It's a 9 hp 125cc engine, even with an open perfectly tuned pipe you're still only going to gain about a 1/2 horsepower. If I remember correctly an air filter, tuned exhaust, and ecu flash only puts you at 10.7 horsepower. Just keep it stock and enjoy it
I plan to. I've modded my Honda Monkey quite a bit and it'll go 67mph, so I'd say an intake/exhaust/cam/high comp piston/ECU tuned to those mods are good for about 10mph at the most on the top end. I don't ride the Trail on the road too often, so I really don't care about top speeds
Agreed. After decades of owning and modding cars and bikes (over 2 dozen), you're always better saving up and getting the drive train and features you want, so if and when you mod, it's minimal. Modding for the most part is a huge waste of money, and usually less reliable. With bikes, if a 125 is too slow, try a 150/160... still too slow?, try a 250-300, and so on....
From all the experiments I've done with the speed, with stock exhaust, different sprockets, Diablo exhaust etc.. etc..... I didn't gain anything until I put the Big Bore Kit on which came with a larger fuel injector. I still didn't need to adjust the ECU with the kit and the HP and torque gains were very noticeable. Take a few minutes to watch a couple of my videos on it to see the difference. The only downside I've experienced so far with the Big Bore Kit is you will suffer with fuel economy. I like your test, it is one that I didn't think of to do. I believe you could probably get some more power out of it if you were able to tweak the ECU for more performance. Good video, I liked it......
Thanks for the feedback and comments bud! I watched a great many of your videos while mine was on preorder 🙏 I’m in the same spot with my Monkey too, have just about all of the bolt on’s and didn’t feel they’ve done much. Even have the ecu tuned for them. BBK’s seem to be a sure thing, and the extra fuel supports it. I’m not chasing HP on this bike as it is too valuable to me as a utility bike around my house and property, but always seek interesting content when I can think of it. Thanks for watching, glad you liked it!
@@John5XR The most important part of the BBK is the torque gain, it just allows the little engine to pull and keep on pulling.... I like how you spun out on the start of your video. Great "foot" clutch work...... ;-)
@@John5XR Un weight the ass of the bike, tilt it almost to the pegs and twist the right grip to spin the rear tire, instant donut........ Don't you wish it had a clutch...... ;-)
Thanks for the great educational video, and a huge thanks for not ruining it with crappy background music while you're talking. I don't know why some people are compelled to add annoying background music throughout the video.
Thanks for watching and the feedback. Adding music to the background is tempting and I’ll do it sometimes because my kids are making noise while in the shop with me or someone is mowing the grass in the vicinity of my shop. I never realized how rare it is to have your environment dead silent until I started doing how-to videos. Every once in a while I’ll have the shop to myself and the kids are busy elsewhere, but most of the time I have to add crappy music too
I second that about background music unless it's something like Lynyrd Skynyrd! JK! although I do enjoy me some Skynyrd, I enjoy hearing what the engine music sounds like as much. Long Live Gasoline power!!
This reminds me of the seventies when my friends and I used to have mopeds in the UK. We used to punch all the baffles out of our exhausts searching for a bit more speed. My dad used to go berserk when there were four or five of us ringa dinging round the neighbourhood:)
@@manstersr old two stroke mopeds are super restricted from the factory. taking the baffle off my batavus gave me a good 7 extra mph, and a LOT of noise lol
It’s a triple combo setup. Intake, fuel delivery, exhaust. If you uncork the exhaust it will run leaner. To compensate for this new lean condition you need more fuel. If it’s carbureted you need a larger jet. If it’s fuel injected you need to reprogram your ECU. You can burn valves, spark plugs and over heat the motor by running it too lean. After your speed run, shut it off and pull the spark plug to see how it’s burning. You should have a nice light chocolate brown color for optimum. If it’s white, it’s too lean. Black is too rich. Unless you have a race bike, leave your spark arrestor in place. It’s a good thing. I just got a new $900 Yoshimura exhaust for my 500 and they forgot to put a spark arrestor in it. They sent me one and I installed it. Now I can ride anywhere legally. Your little 125 is a gem. Performance isn’t what it was designed for. I have a deposit in for the 2022 because they’re sold out everywhere in SoCal. It’s going to be for my wife. You’re lucky to have yours!
@@charkswitlazers Finally, yes. I think it was about a 7 month wait total. The dealer raped me. They lost a customer forever because of their $1000 markup.
@@herbiesnerd damn. I would have walked. That’s why I’m not buying anything at the moment. I refuse to pay more than msrp. I hope these dealers that screw over customers get hit HARD when the recession gets rough. Do you at least like the bike? Btw, I’m in socal. Which dealer was it?
@@charkswitlazers I love the bike. Got it for my wife, but honestly it’s one of those bikes you just want to keep forever for anyone to use because it’s so cool. Coyne Powersports in Banning.
@@techtard829 Nope. Lean. With the emissions requirements they are set lean on modern bikes. You need to add fuel and un restrict both the air box and exhaust. Way back in the day they tended to ship rich and all you had to do was uncork it.
@@charlespratt8663 Ah, you only mentioned restricting the airbox and exhaust, in regards to lean and corked. Alone, those would create a rich fuel mixture. But, they also use lower jetting(would it be metering on F.I.?), to lower fuel usage. Interesting. Fortunately, my bread and butter are classic two stroke Yamahas. RDs, RZs, TZs, etc. I dabble elsewhere. But, have not found myself having to deal with any of this modern fuel mapping stuff.
From past experience w/ other Honda motorcycles, you're more likely to unlock some top speed potential by removing sound control devices from the intake tract & wearing earplugs under your helmet; the company seems to go to great lengths to minimize intake roar and this will affect the performance all the way on top w/ the throttle WFO.
I used to road race box production class many years ago. Engineers back then had already designed the engine flow optimized for the stock specifications. So if you threw a header on there with no intake modifications, there was often a net loss in power. Not surprised by the results. I 'm going to have to come out of retirement and get one of these little red Hondas. If I can find one that is.
This bike fits my needs 1000%, which is to work around my house and go wherever I need it to go. It was a simple experiment to see if it did anything. Everyone seems to be missing that point and thinking I am looking to go 70mph or start forest fires
I like the sound without the spark arrestor. Was just enough extra noise for this bike. Not too much. For no money and almost no loss in top speed I think this is great to do for fun of it. Especially since you can change back and forth with little effort
Cool test. I wonder if going 20 some miles and letting the ECU adjust would have changed the results? Looking forward to your long term review of the Yoshimura exhaust. I like the quiet stealthy nature of the factory pipe. However more power and speed without being too much louder, would be nice. Thank you for the video and content type.
If you are driving off road, through a hay field or in the forest you do need that spark arrestor in there. Apart from the risk of starting a fire some jurisdictions will impose a heavy fine for not having it in place. Thanks for the video.
See if it increases your speed a little, as you might have more miles than I. I now wish I would have left it out for at least 20-miles to let the ecu adjust, as that’s what usually needs done. Or, reinitialize the ecu even, but I wasn’t gonna keep it out unless it sounded super good cause I like the quiet stock sound
@@John5XR I'll gear up later today and give it a run, I took it out last night but have not started it to see what it sounds like. Look for video this weekend sir. I'll give you a shout out.
Hi just fitted aftermarket full Yoshimura Exhaust no cat Converter, removed the rear rack , fitted Cover over the Air box, lot more Torque nice Sound looks great on my new CT125 Hunter ,just keeping a I on the Spark Plug don't want it running to lean.
@@John5XR Hi John top speed on 98 fuel Australia 103km standard have not tested with new parts fitted,do U think the ECU would b need turned 4 the Aftermarket parts I fitted? Thanks
Reminds me of when I picked up my first two CT70s and the kid that had them had hacked the muffler in half on the one that ran and told me it sounded like a Harley. Right!. I replaced it with a new one and couldn't feel any difference in power, it had more with the full muff and baffle if anything. Most people think it's faster because it sounds faster. I'm glad you showed that it actually runs better the way it was configured from the factory and maybe people won't be starting fires in the woods. Also, most modern cats are non-restrictive so that probably won't make a difference either, just make it stink and pollute more. If you want more power just put a turbo on it with a K&N cone air filter, or you could just get a faster bike to begin with. My recommendation is a Hyabusa, 90+mph in first gear, over 150 in 3rd. The kind of bike you give to a beginner to learn how to respect a bike...or die.🤣 BTW, Def Leppard sucks!
I love this comment, this video caused so much static because people thought I took out the arrestor and was going around starting forest fires. If watched all the way through like you did, anyone would be able to see that I said it didn’t work and put it back in. Thank you sir for the story, comment, and watching all the way through!
@@John5XR Oh sorry, I either missed your comment on the video or didn't watch to the end. Probably watching at 3 am and half asleep anyway. I'm glad you did explain the results and hope people won't just take them out of their bikes based on your vid title and watching half of it. Maybe you should have said or put in the title to watch to the end for results of the test.
What? Def Leppard definitely rocks. I don't think most beginners start on a Hayabusa for fear of death lol. If you have a Hayabusa that you'd like to give to a beginner then lmk. I'll take it. Dude just wants a super cub but bought the hunter cub. I knew the stock was gonna go faster from the get-go.
Your decrease in top speed is probably due to an increase in a leaner running condition. You may have been able to see a difference in the spark plug if you had done a before and after comparison. The point is, you increased exhaust flow without increasing fuel, so your results make sense. 👍🏾
I've been wondering what was behind the exhaust caps on these things. Granted I've only ever built motorized bicycles, one of the first things I always do is pull the exhaust cap off and cut the tube. I wonder if this kind of modification is better off on a two stroke? Like you said though, Honda has this motor tuned with that exhaust and love em or hate em, you really can't argue with Honda reliability
50 years ago we had a new CT70 as did one of our camping family buddies. That guy was handy and he pulled the spark arrestor and drilled a few small holes in the air cleaner housing. ALso rejetted the carb for the "increased breathing". Both bikes ran dead even from start up to top end (about 40mph). ;) And that was long before any added emissions junk. Sure sounded meaner. Always been that way.
Bought Honda XR650L new in 1995 and talk about corked up and restricted. Jetted it up twice, the exhaust outlet same size as your 125 and had 5X displacement. Parts desk had number for bigger silencer for a 4 wheeler, still didn't help. Noticed 3 Chambers inside muffler and with a 12"long 3/8" (use to build decks) bit I drilled into each Chamber as deep as bit would go. Put silencer back in and the difference was night and day. Had a nice bark...not too loud and increased mid range torque you could feel in the seat of the pants. Put 4.7 Clark gas tank on and the XR600 gearing. Could pull wheelies in second gear just jerking throttle open & I weigh 190#. Still Cruise at 60 mph without over revving engine...and it had gorilla like power in Pisgah National Forest on logging roads. Still got 50 MPG. Stock gearing would do 115 easy and had to be going 65 to shift into 5th gear, way to high for the mountains and using engine for braking. That was my experience.
And sitting here in Nor Cal, August 27th 2021, with 100's of thousands of acres of National Forest on fire (yeah, literally!)... I think leaving the spark arrestor functional is a pretty good idea! .
Temporary experiment. Watching any of the following videos after this would easily show that the experiment wasn’t worth it. No forest fires were started 😐
@@John5XR Yes I watched through... you Did mention a slight increase in exhaust sound so, just incase that was appealing to any of your audience, I thought I'd mention a downside of even CONSIDERING! tampering with the spark arrestor screen. No bigee (unless it starts a 300,000 acre fire!). Dixie fire - Northern California, August 2021
And I appreciate your feedback knowing you’ve seen the video through instead of putting me on trial for “almost starting a forest fire” without ever having ridden in a forest! 😂🤷🏼♂️ A “quiet” experiment is all it ever was 🙏
Sounds about what I would expect from a gutless little 125 without a spark arrestor. I love the little trail 125 but I think I would also leave the spark arrestor in because it is not a bike that you really want to announce your presence on lol
see if you can use a high flow intake filter in place of the OEM filter as well as removing the spark arrester. also, try getting an extra arrester and cut off near the plate you mentioned so you can replace the end of the muffler, if only for looks. it might add a slight resistance. Enough to bring back that 1 -2 mph you lost. Another thing you can do, is see if you can get a big bore kit that will take it to like 150cc or so.
You may want to see what can be done to increase the gas flow through the Fuel injection system now that you have increased the exhaust flow. They have to be tuned together.
Typically with the small bore Hondas you would have the ecu flashed by one of the several talented tuners out there, but I’m not aware of any who are doing the Trail yet. For the monkey, that is fairly easy to accomplish
Had Honda 50 put on 16k, while riding through Beverly Hills police motorcycle officer who ticket me because of missing baffle which was over 12 inches lone so friend of my cut down it to one inch did it make a difference maybe. Back in 1965 to fill up the gas tank was around 50 cents.
When you lower the exhaust back pressure, you need to change the size of your main jet if you have a normal carb, or reprogram your computer if you are fuel injected, if you want to realize any power gain.
Careful Mike! There's A LOT of commenters on here that will accuse you of starting a forest fire like they're assuming I will (even though I left this baffle in because it didn't add power)
I am not sure that top speed is going to be the metric by which to gage whether there was an increase in hp. In this case obviously there was a decrease, but as I understand it, the computer driven EFI acts as a governor and won't let the engine go over a set RPM on the road. Had the speed been identical before and after the spark arrestor been removed then another way to try it might have been to gear up the sprockets to the point where (by using a tiny tach) that top EFI governed RPM couldn't be reached with stock exhaust and then run the experiment. Probably best to use the GPS method as the speedometer will not be accurate any longer. Then if the bike does go faster then you will know if the mod helped hp or not.
Out of curiosity since you've had it a while. Any future plans for an after market exhaust? I was eyeballing the Yoshimura Cyclone. Pricey but very cool looking and sounding.
There’s a few more I’d like to try, but don’t think any of the high mounts will sound any different. Low mount would be the way to get a different sound, but I’m not a fan of the low mount design due to riding offroad mostly
I wonder if simply adding a 5th gear with a taller ratio on the top end would help. Intake and exhaust is a super finicky balance. Id not mess with it unless you have full ecu flash and tune.
The screen will carbon up after a while, and restrict flow, but is a simple maintenance item if you remember to do it. If you don't want to bother with that, you could punch out just the screen.
This is what peaked my curiosity when I read the manual. I like the quiet sound of the exhaust though and want it in, but the experiment was fun to try
Your speed test is fine, but I think you should measure a mile distance and then run that mile for time. That way your tests accomodate for power and a different torque curve.
Honda runs everything super lean from the factory. Opening the exhausts and intake probably just best prep for mild jetting. That’s really the best way to get better top speed or power from Honda. If yo get any leaner, your pipes will blue and you’ll lose power. Generally.
Not just Honda, all manufacturers run the street legal stuff as lean as possible to pass EPA regulations. In all honesty with the cost of aftermarket modern FI intake kits, air box or filter kits and aftermaket exhaust and aftermarket ecm or reflashing the stock ecm not to mention for street use your bike will no longer actually be legal if you need more power just move up to a bike that stock fills your needs. Will probably be no more expensive, be actually street legal and not void your warranty. Say the trail 125 properly modded for instance would actually end up being only a few hundred dollars less than a street legal CRF 300L which would have much better power stock than the trail 125 modded. Buy the right bike to begin with is the best move.As far as long term reliability and minimum issues usually the more stock it is the better off you are as an owner.
One thing you can do...make sure at wide open throttle the carb slide completely clears the venturi. Some bike the spring will coil bind prior to slide clearing venturi
agreed, I rode for about two miles and knew it wouldn't be enough to let the ecu adapt to the change, but didn't plan to keep it out anyways. More of a test of curiosity.
I guess they put a different model muffler on the Australian CT125 vs the US Trail125... My CT125 doesn't have that removable piece at the end of the muffler body to unbolt.. it's a welded one-piece muffler body.
Exhaust back pressure on any four stroke engine increases the power range, so instead of getting majority power at lower rpm you get power right through to high rpm. The only thing that makes a vehicle go faster is gearing.
You need to add more airflow and more fuel when you relieve the back pressure you just need to raise the fuel pressure up a pound or so you'll get that mile an hour back
It might be related to backpressure and scavenging in the exhaust. Backpressure is when the exhaust flows (typically) down the center of the exhaust, but air flows around the edges back towards the manifold in reverse. You increase backpressure by removing the arrester. But also, the factory design might include some induced scavenging of exhaust, so that the restricted flow actually creates a low pressure that "sucks" the exhaust out more efficiently. Don't know if either is true here, but those could be contributing factors.
Exhaust dynamics are so complicated and counter intuitive that you really need to understand them or you just make it worse most of the time. Better yet, leave it to the professionals, even though I've heard plenty of people tell me that aftermarket cans and such usually reduce power unless it's a complete header system from a manufacturer with a racing background. And then some people just think it's faster if it's louder.
Back pressure is much more a 2 stroke thing, you need it so when kids remove the baffle they often loose performance. The baffle on a four stroke is about sound suppression and shouldn't make much difference
@@nickcarter9538 someone was almost talking like this wasn't too stroke probably a lot of people don't really know and they start using terminology they don't know anything about just doesn't have scavenging ports it has a port for the exhaust and a port for the intake valve
Thank you for the video. I got mt CT 125 2 days ago after a 10 month wait! It is SO cool. We have lots of off road and truck trails here but I also live on a paved mountain rode with 2 miles of it at a 5% grade going 6 miles, (flat) to the nearest town. I am hoping that wont be too much for the bike. Any thoughts? we will find out soon.
If it flows more air without the arrest or, you’d then also need to remap the injector to deliver more fuel. Otherwise, you’ve leaned out an already lean motor which will always result in less power.
Just installed a windshield/windscreen on my BUDDY 50 scooter ..GAINED 5 MPH on TOP END with windshield ! .plus much less wind noise ..warmer in cool weather ..win win 👍
I wouldn't bother trying to get a few mph more out of the T125, it's not logical, like trying to soup up a farm tractor to go a little faster. I owned a '63 and still have a 68 CT-90. They would only go 45+ mph. I always wished they had conventional foot shift and hand clutch. I wonder if the supplied battery needs to be helped with a "battery minder" to keep it in good shape and reliable to start the bike if you ride a few miles once per week. Also wonder whether kick starting will work when battery is not able to start with electric starter.
If you do this spark arrestor mod do not operate it in any forest or desert area because when they track you down after the fire you start and you receive the massive life long financial ruin that follows you will learn the consequences .
good thing it went back in as soon as I hit stop on my gopro. I wish everyone would watch the whole thing before posting their fears of me starting a forest fire...
@@John5XR John it is not fears of you starting a forest fire. If the video encourages 1000 other CT125 owners take their spark arrestors out then maybe one might accidentally start a forest fire. As I write this over 92k have watched the video. It isn't inconceivable that a few thousand might proceed to remove or modify the arrestor to get the throatier exhaust growl. It did sound good - but with UA-cam stardom comes great responsibility! 😁
plug read would be interesting to do, but since it's injected the only thing I'd be able to change is the fuel map, which I can't even change as I don't have the ability to do that. No biggie, just a simple experiment to see what happened as I've had it help on other bikes (all carbureted though)
mine is now 1 year old yesterday. and it loves 50 mph. but on good days i have seen 62 mph. and its still 100% stock. its not for from needing a new chain and when i do i'm thinking of going to a 15/ 41 i will have the same top speed. but when i hit hills for a few days in a row i can drop my front sprocket to a 13 or 14 and get more power. but with a stock bore engine i dont see getting anymore power or speed out of it.
Update. i took mine out and it seemed to give me a little more power lower end but the same top speed. and made more noise. so i just cut the screen off and put it back on and same thing more lower end power seemed to hit top speed sooner but still the same. now i'm thinking of cutting the tube off at the mount and see what that might do because it wont have to make 3 trips through the muffler.
In case you never checked it via GPS but the stock speedometer is about 2 mph higher than your actual speed. Everyone on the forums report the same thing. I'm not real surprised the speed didn't change much. Sometimes more back pressure provides better performance. The engine is tuned for a certain amount of back pressure. Of course there are too many variables to be certain. Same wind as before? Exactly? Same wind speed and same direction, exactly? This bike is very susceptible to any small changes like that. Also, when you open the exhaust up, the normal thing to do is you have to increase the breathing (more intake to take advantage of more exhaust). Again, it was a quick test that proved nothing because you didn't increase the airflow to match the new exhaust free-flow and the weather is your biggest factor. But it serves to tell people "don't bother taking out the spark arrestor". (which is illegal in the US anyway.)
I cross-reference all of these test rides with the REVER app, which tracks the ride and provides the top speed achieved. It’s gps based. My Speedo was 1mph slower than the app, close enough for me. You might not be like me, but when I flipped through the manual and saw a big potential restriction in the pipe that could be removed with a few bolts, there was no way I wasn’t gonna take it out and see what it did. Whether it worked or not, I wanted to see what happened. I’m a racer and a tinkerer, even if the experiment doesn’t work on paper, I find the experience fun and interesting nonetheless. You say it proved nothing? Absolutely it proved something: that it didn’t help top speed! Lol! And I’m not worried about legality, as here in Florida we run motorcycles with aftermarket pipes with no issues from the law. If I’m riding in a US forestry or park, yes it is required to have a spark arrestor and I would do so
@@John5XR I installed the opmid speedometer multi-meter so I could set my speedo to read exactly what the GPS says. Also, like most of the guys that got these anemic bikes, I've been changing the gearing which put the speedometer a long ways off so the Opmid makes up for those experiments. I don't know why your speedo reads slower than everyone else's. All cars/trucks, bikes tend to read higher (they say it has something to do with keeping you at the speed limit because everyone speeds a little), but all manufacturers do it and pretty much always have. Like everyone else, mine read almost 2 mph higher than I was going and when I geared it down it was off by at least 5 mph. I hated having to think about what my speed really was all the time when I'm in town, and of course it affects your odometer so your mpg calculations can be way off. BTW, I got 140 mpg yesterday. I've been doing some slow riding while my wife gets her new trike broken in.
Riding a lot in the bush up in British Columbia I'd never even think about it. Forest fires are such a huge problem I don't want to be the guy to add to it.
A lot of these small bikes from 50cc up 125cc maybe a little bigger used to have a small diameter piece of pipe welded into the exhaust where it bolts onto the head to restrict them I removed loads of them when I was younger for myself and friends who had bikes, it takes some hammering to get them out but it always had good results but taking out baffles never done anything other than change the noise so take a look.
Nice one john,the postmans bike is a legendary Honda,,in Australia thay have mad desert rally on ct110s each year,",the postmans chalenge" ,,,,,,the cat IS a really restrictive unit,,,im gonna cut the cat and leave the muffler on my 2020 grom,,
@@John5XR we jus got them here,,i like the desert storm colour,,really cool real world bikes,,,yoc can have a shed full of bikes, vut the one you need is the posty,,,lots of ozy deckoutwhith xr 200 tank gard,seat ,rims,if you take ego out of equation its NUMBER 1☝️🌎
Think the ecu has a break in. After a certain mileage the bike will open up and go faster. Be interesting to find out if this is true or not. I've seen videos after a certain mileage the bike will go up to 65 close to 70
A modern ecu usually restricts the engine to only make a certain amount of power. Reduces warranty calls and improves their reliability reputation. The days of just turning a screw on the carb are over.
Yep. You’re right. Honda looks to have done a great job tuning the spark arrestor into the exhaust. That arrestor is a behemoth compared to the other aftermarket exhausts. Wonder if you’ll have any more HP after break-in and first oil change?
It’s a huge restriction, but if you look into the pipe there are other smaller pipes in there as well, kind of like a 6-shooter barrel, it’s weird. Once I saw those I didn’t think there would be a huge flow increase from removing just the spark arrestor, but was curious to try either way. With an aftermarket pipe and ecu reflash, it would probably add a good amount of power and speed to this bike, BUT, I like the super quiet exhaust as I use this bike around the house
Didn't he say he's owned his CT125 for a couple of years now? Ive watch an ass load of videos on these Honda Mini cycles today so I may get what was said, mixed up! Great little machine
I wish Honda would come out with the sub transmission. The first year they came out with the ct110, they didn't the sub transmission. The next year they did, and you could then ride better off road, and climb any hill and crawl. I still have mine but was hoping the 125 would have that sub transmission. We'll see.
If you ride off road or on BDRs , forest service roads, public lands spark arrestors are required. Regardless of sounds or horsepower gains removing it is not advisable. Many aftermarket exhaust systems include spark arrestors. The reason they are there is for what they name implies which prevents fires . JS.
It's a 9 hp 125cc engine, even with an open perfectly tuned pipe you're still only going to gain about a 1/2 horsepower. If I remember correctly an air filter, tuned exhaust, and ecu flash only puts you at 10.7 horsepower. Just keep it stock and enjoy it
I plan to. I've modded my Honda Monkey quite a bit and it'll go 67mph, so I'd say an intake/exhaust/cam/high comp piston/ECU tuned to those mods are good for about 10mph at the most on the top end. I don't ride the Trail on the road too often, so I really don't care about top speeds
Thats nearly a 20 pct increase , you sound zany
@@John5XR from 60 to 70 is alot
Agreed. After decades of owning and modding cars and bikes (over 2 dozen), you're always better saving up and getting the drive train and features you want, so if and when you mod, it's minimal. Modding for the most part is a huge waste of money, and usually less reliable. With bikes, if a 125 is too slow, try a 150/160... still too slow?, try a 250-300, and so on....
From all the experiments I've done with the speed, with stock exhaust, different sprockets, Diablo exhaust etc.. etc..... I didn't gain anything until I put the Big Bore Kit on which came with a larger fuel injector. I still didn't need to adjust the ECU with the kit and the HP and torque gains were very noticeable. Take a few minutes to watch a couple of my videos on it to see the difference. The only downside I've experienced so far with the Big Bore Kit is you will suffer with fuel economy. I like your test, it is one that I didn't think of to do. I believe you could probably get some more power out of it if you were able to tweak the ECU for more performance. Good video, I liked it......
Thanks for the feedback and comments bud! I watched a great many of your videos while mine was on preorder 🙏 I’m in the same spot with my Monkey too, have just about all of the bolt on’s and didn’t feel they’ve done much. Even have the ecu tuned for them. BBK’s seem to be a sure thing, and the extra fuel supports it. I’m not chasing HP on this bike as it is too valuable to me as a utility bike around my house and property, but always seek interesting content when I can think of it. Thanks for watching, glad you liked it!
@@John5XR The most important part of the BBK is the torque gain, it just allows the little engine to pull and keep on pulling.... I like how you spun out on the start of your video. Great "foot" clutch work...... ;-)
Haha, did you see the outro?
@@John5XR Un weight the ass of the bike, tilt it almost to the pegs and twist the right grip to spin the rear tire, instant donut........ Don't you wish it had a clutch...... ;-)
Lol, well on this bike I don’t wish for the clutch because of all the utility work I do with it, but that’s why I have my monkey and Grom 😁
Thanks for the great educational video, and a huge thanks for not ruining it with crappy background music while you're talking. I don't know why some people are compelled to add annoying background music throughout the video.
Thanks for watching and the feedback. Adding music to the background is tempting and I’ll do it sometimes because my kids are making noise while in the shop with me or someone is mowing the grass in the vicinity of my shop. I never realized how rare it is to have your environment dead silent until I started doing how-to videos. Every once in a while I’ll have the shop to myself and the kids are busy elsewhere, but most of the time I have to add crappy music too
I second that about background music unless it's something like Lynyrd Skynyrd! JK! although I do enjoy me some Skynyrd, I enjoy hearing what the engine music sounds like as much. Long Live Gasoline power!!
This reminds me of the seventies when my friends and I used to have mopeds in the UK. We used to punch all the baffles out of our exhausts searching for a bit more speed. My dad used to go berserk when there were four or five of us ringa dinging round the neighbourhood:)
Two strokes depended on that baffle for tuning so much. Didn't that make them lose power?
@@manstersr old two stroke mopeds are super restricted from the factory. taking the baffle off my batavus gave me a good 7 extra mph, and a LOT of noise lol
That sounds like a very good time and even better memories
Good times!
@@manstersr You are correct, 2 cycle engines need the tuned exhaust systems to run correctly.
Enjoyed watching your experiment, I was wondering about taking mine out as well. You saved me the trouble.
Finally a comment that isn’t about me starting forest fires! Glad this helped you 👍
Awesome video i really appreciate the time you spent on this test
God bless you and stay safe out there 🙋♂️🇬🇧
Thanks my friend!
It’s a triple combo setup. Intake, fuel delivery, exhaust. If you uncork the exhaust it will run leaner. To compensate for this new lean condition you need more fuel. If it’s carbureted you need a larger jet. If it’s fuel injected you need to reprogram your ECU. You can burn valves, spark plugs and over heat the motor by running it too lean.
After your speed run, shut it off and pull the spark plug to see how it’s burning. You should have a nice light chocolate brown color for optimum. If it’s white, it’s too lean. Black is too rich.
Unless you have a race bike, leave your spark arrestor in place. It’s a good thing.
I just got a new $900 Yoshimura exhaust for my 500 and they forgot to put a spark arrestor in it. They sent me one and I installed it. Now I can ride anywhere legally.
Your little 125 is a gem. Performance isn’t what it was designed for. I have a deposit in for the 2022 because they’re sold out everywhere in SoCal. It’s going to be for my wife. You’re lucky to have yours!
Did you get your bike yet?
@@charkswitlazers Finally, yes. I think it was about a 7 month wait total. The dealer raped me. They lost a customer forever because of their $1000 markup.
@@herbiesnerd damn. I would have walked. That’s why I’m not buying anything at the moment. I refuse to pay more than msrp. I hope these dealers that screw over customers get hit HARD when the recession gets rough. Do you at least like the bike?
Btw, I’m in socal. Which dealer was it?
@@charkswitlazers I love the bike. Got it for my wife, but honestly it’s one of those bikes you just want to keep forever for anyone to use because it’s so cool.
Coyne Powersports in Banning.
A lot of bikes are shipped both lean and corked ie restrictive air box and exhaust. You typically need to address all three to have an impact.
You mean rich, not lean...
@@techtard829 Nope. Lean. With the emissions requirements they are set lean on modern bikes. You need to add fuel and un restrict both the air box and exhaust. Way back in the day they tended to ship rich and all you had to do was uncork it.
@@charlespratt8663 Ah, you only mentioned restricting the airbox and exhaust, in regards to lean and corked.
Alone, those would create a rich fuel mixture. But, they also use lower jetting(would it be metering on F.I.?), to lower fuel usage. Interesting.
Fortunately, my bread and butter are classic two stroke Yamahas. RDs, RZs, TZs, etc. I dabble elsewhere. But, have not found myself having to deal with any of this modern fuel mapping stuff.
Real world testing. Love it.
From past experience w/ other Honda motorcycles, you're more likely to unlock some top speed potential by removing sound control devices from the intake tract & wearing earplugs under your helmet; the company seems to go to great lengths to minimize intake roar and this will affect the performance all the way on top w/ the throttle WFO.
P.S. Your thumbnail and title game is on-point. Nicely done!
Thanks man, it’s a fine line between being click-baity and not baity enough
Thanks for making this video!
Thanks for watching!
I used to road race box production class many years ago. Engineers back then had already designed the engine flow optimized for the stock specifications. So if you threw a header on there with no intake modifications, there was often a net loss in power. Not surprised by the results. I 'm going to have to come out of retirement and get one of these little red Hondas. If I can find one that is.
lots of science behind exhausts, which is why experimentation is so fun!
I wish I were living in Florida and owning a Trail 125…
10 miles better than my old CT 90, back in the 70's
Back pressure has already been factored in by Honda. Somehow I just think I would leave a $3,999 125 cc bike alone, or move up to a Rebel.
Watch the rest of the video 👍
@@John5XR I watched it all that was my point. I would not have taken it apart in the first place, I would have bought a bike that fit my needs.
This bike fits my needs 1000%, which is to work around my house and go wherever I need it to go. It was a simple experiment to see if it did anything. Everyone seems to be missing that point and thinking I am looking to go 70mph or start forest fires
@@John5XR some people will never understand and it's a waste of time trying to explain
@bulletproof47 I’ve begun to notice that… 🤦🏼♂️🤷🏼♂️
I like the sound without the spark arrestor. Was just enough extra noise for this bike. Not too much. For no money and almost no loss in top speed I think this is great to do for fun of it. Especially since you can change back and forth with little effort
I would go for a K and N air filter as well, help to balance output and input
I wouldn't stop using the foam style or paper style that k&n filters end up damaging engines by dusting them 🤷🏼♂️
that'd be interesting to test
Yes they allow more dirt into the engine. Keep the foam.
Where to buy your new Honda trail where do you buy it
John, much appreciated.. thanks..
Thanks for watching!
Great experiment. Thanks for sharing.
Thanks for watching!
Cool test. I wonder if going 20 some miles and letting the ECU adjust would have changed the results? Looking forward to your long term review of the Yoshimura exhaust. I like the quiet stealthy nature of the factory pipe. However more power and speed without being too much louder, would be nice. Thank you for the video and content type.
Nice test. Thanks. I have the 2021
Trail 125. I only been at 58 mph.
58 is good for the Trail! I’ve only been able to squeeze out 57
If you open up the exhaust you need to increase air flow and fuel or you will be running lean.
The stock ECU easily manages the fuel with room to spare. A quick reset or just letting run for a while and its fine.
If you are driving off road, through a hay field or in the forest you do need that spark arrestor in there. Apart from the risk of starting a fire some jurisdictions will impose a heavy fine for not having it in place. Thanks for the video.
opening the exhaust can only give an increase if its over carbureted.what you proved is what you said,Honda got the flow spot on.
Plan on taking my out before the weekend just for fun, great idea to do. See if I can get a new video up before I travel again.
See if it increases your speed a little, as you might have more miles than I. I now wish I would have left it out for at least 20-miles to let the ecu adjust, as that’s what usually needs done. Or, reinitialize the ecu even, but I wasn’t gonna keep it out unless it sounded super good cause I like the quiet stock sound
@@John5XR I'll gear up later today and give it a run, I took it out last night but have not started it to see what it sounds like. Look for video this weekend sir. I'll give you a shout out.
Can’t wait!
@@John5XR LOL, I guess I can. Went out of town with my wife this weekend and start business travel again on Sunday. Hope I have time soon.
Hi just fitted aftermarket full Yoshimura Exhaust no cat Converter, removed the rear rack , fitted Cover over the Air box, lot more Torque nice Sound looks great on my new CT125 Hunter ,just keeping a I on the Spark Plug don't want it running to lean.
Wow! That new Yoshimura exhaust is nice, I wish they’d send me one to test. Did your top speed increase at all?
@@John5XR Hi John top speed on 98 fuel Australia 103km standard have not tested with new parts fitted,do U think the ECU would b need turned 4 the Aftermarket parts I fitted? Thanks
So if Google is correct, that’s 64mph! Typically just the exhaust won’t require an ecu tune
Did you have to reset the ecu before running the new exhaust?
Cool experiment, enjoyed watching it
Reminds me of when I picked up my first two CT70s and the kid that had them had hacked the muffler in half on the one that ran and told me it sounded like a Harley. Right!. I replaced it with a new one and couldn't feel any difference in power, it had more with the full muff and baffle if anything. Most people think it's faster because it sounds faster. I'm glad you showed that it actually runs better the way it was configured from the factory and maybe people won't be starting fires in the woods. Also, most modern cats are non-restrictive so that probably won't make a difference either, just make it stink and pollute more. If you want more power just put a turbo on it with a K&N cone air filter, or you could just get a faster bike to begin with. My recommendation is a Hyabusa, 90+mph in first gear, over 150 in 3rd. The kind of bike you give to a beginner to learn how to respect a bike...or die.🤣
BTW, Def Leppard sucks!
I love this comment, this video caused so much static because people thought I took out the arrestor and was going around starting forest fires. If watched all the way through like you did, anyone would be able to see that I said it didn’t work and put it back in. Thank you sir for the story, comment, and watching all the way through!
@@John5XR Oh sorry, I either missed your comment on the video or didn't watch to the end. Probably watching at 3 am and half asleep anyway. I'm glad you did explain the results and hope people won't just take them out of their bikes based on your vid title and watching half of it. Maybe you should have said or put in the title to watch to the end for results of the test.
What? Def Leppard definitely rocks. I don't think most beginners start on a Hayabusa for fear of death lol. If you have a Hayabusa that you'd like to give to a beginner then lmk. I'll take it. Dude just wants a super cub but bought the hunter cub. I knew the stock was gonna go faster from the get-go.
top speed is related to engine rpm will only go faster if you alter the sprockets to rise the gearing
That's only true if you're hitting the rev limiter and that's what's limiting your top speed.
Your decrease in top speed is probably due to an increase in a leaner running condition. You may have been able to see a difference in the spark plug if you had done a before and after comparison. The point is, you increased exhaust flow without increasing fuel, so your results make sense. 👍🏾
Wouldn't fuel injection automatically adjust for that?
@@chrishoesing5455 no needs to be programmed to exceed presets
My old XR100 was such an awesome bike. It's no wonder these things are impossible to find.
They’re abundant now 😂
I've been wondering what was behind the exhaust caps on these things. Granted I've only ever built motorized bicycles, one of the first things I always do is pull the exhaust cap off and cut the tube. I wonder if this kind of modification is better off on a two stroke?
Like you said though, Honda has this motor tuned with that exhaust and love em or hate em, you really can't argue with Honda reliability
50 years ago we had a new CT70 as did one of our camping family buddies. That guy was handy and he pulled the spark arrestor and drilled a few small holes in the air cleaner housing. ALso rejetted the carb for the "increased breathing". Both bikes ran dead even from start up to top end (about 40mph). ;) And that was long before any added emissions junk.
Sure sounded meaner. Always been that way.
Bought Honda XR650L new in 1995 and talk about corked up and restricted. Jetted it up twice, the exhaust outlet same size as your 125 and had 5X displacement.
Parts desk had number for bigger silencer for a 4 wheeler, still didn't help. Noticed 3 Chambers inside muffler and with a 12"long 3/8" (use to build decks) bit I drilled into each Chamber as deep as bit would go. Put silencer back in and the difference was night and day. Had a nice bark...not too loud and increased mid range torque you could feel in the seat of the pants. Put 4.7 Clark gas tank on and the XR600 gearing. Could pull wheelies in second gear just jerking throttle open & I weigh 190#. Still Cruise at 60 mph without over revving engine...and it had gorilla like power in Pisgah National Forest on logging roads. Still got 50 MPG. Stock gearing would do 115 easy and had to be going 65 to shift into 5th gear, way to high for the mountains and using engine for braking. That was my experience.
And sitting here in Nor Cal, August 27th 2021, with 100's of thousands of acres of National Forest on fire (yeah, literally!)... I think leaving the spark arrestor functional is a pretty good idea!
.
Temporary experiment. Watching any of the following videos after this would easily show that the experiment wasn’t worth it. No forest fires were started 😐
@@John5XR Yes I watched through... you Did mention a slight increase in exhaust sound so, just incase that was appealing to any of your audience, I thought I'd mention a downside of even CONSIDERING! tampering with the spark arrestor screen. No bigee (unless it starts a 300,000 acre fire!). Dixie fire - Northern California, August 2021
Great little bikes...way more fun then massive machines...interesting vid..
thanks! I think so, but also have no need for the massive road going bikes either
That washer goes between the cap and carb piston.
You’re logical, adventurous and (judging by your replies to others), intelligent. I enjoyed this quiet experiment LOL 😆
And I appreciate your feedback knowing you’ve seen the video through instead of putting me on trial for “almost starting a forest fire” without ever having ridden in a forest! 😂🤷🏼♂️ A “quiet” experiment is all it ever was 🙏
Great video now I don't have to do this myself
Sounds about what I would expect from a gutless little 125 without a spark arrestor. I love the little trail 125 but I think I would also leave the spark arrestor in because it is not a bike that you really want to announce your presence on lol
Thanks, great video
Thanks! I rare supporter of my experiment! lol
Probable need to tune your EFI after removing the arrester
see if you can use a high flow intake filter in place of the OEM filter as well as removing the spark arrester. also, try getting an extra arrester and cut off near the plate you mentioned so you can replace the end of the muffler, if only for looks. it might add a slight resistance. Enough to bring back that 1 -2 mph you lost. Another thing you can do, is see if you can get a big bore kit that will take it to like 150cc or so.
You may want to see what can be done to increase the gas flow through the Fuel injection system now that you have increased the exhaust flow. They have to be tuned together.
Typically with the small bore Hondas you would have the ecu flashed by one of the several talented tuners out there, but I’m not aware of any who are doing the Trail yet. For the monkey, that is fairly easy to accomplish
I saw the same result on another video that opened up the intake by drilling a hole in the intake box. It wouldn't even idle..
Had Honda 50 put on 16k, while riding through Beverly Hills police motorcycle officer who ticket me because of missing baffle which was over 12 inches lone so friend of my cut down it to one inch did it make a difference maybe. Back in 1965 to fill up the gas tank was around 50 cents.
Fun experiment, thanks John.
When you lower the exhaust back pressure, you need to change the size of your main jet if you have a normal carb, or reprogram your computer if you are fuel injected, if you want to realize any power gain.
I see a bottle opener next to the cup holder.
My question is where do you find a trail 125, to heck w/changes !
Brother that’s a nice piece of property there. Flat with trees and shade. That great house in the back. Jealous!
Checking the performance needs to be the same temperature.. 60' x 70' x 80'
It may not have enough back pressure. I'd at least figure out how to put the cap on.
We were taking baffles and spark arresters out of Honda sl 100s ,sl125s ,CT 90s and mini trails since the 60s and 70s.
Careful Mike! There's A LOT of commenters on here that will accuse you of starting a forest fire like they're assuming I will (even though I left this baffle in because it didn't add power)
I am not sure that top speed is going to be the metric by which to gage whether there was an increase in hp. In this case obviously there was a decrease, but as I understand it, the computer driven EFI acts as a governor and won't let the engine go over a set RPM on the road. Had the speed been identical before and after the spark arrestor been removed then another way to try it might have been to gear up the sprockets to the point where (by using a tiny tach) that top EFI governed RPM couldn't be reached with stock exhaust and then run the experiment. Probably best to use the GPS method as the speedometer will not be accurate any longer. Then if the bike does go faster then you will know if the mod helped hp or not.
Out of curiosity since you've had it a while. Any future plans for an after market exhaust? I was eyeballing the Yoshimura Cyclone. Pricey but very cool looking and sounding.
There’s a few more I’d like to try, but don’t think any of the high mounts will sound any different. Low mount would be the way to get a different sound, but I’m not a fan of the low mount design due to riding offroad mostly
@@John5XR Definitely high mount on this bike. I will say I do like the stealthness of the oem tho.
I wonder if simply adding a 5th gear with a taller ratio on the top end would help. Intake and exhaust is a super finicky balance. Id not mess with it unless you have full ecu flash and tune.
Are you gonna turn it in to a chopper? K-speed did a cool chopper build to one
Nope, I use this bike too much to mess with functionality
The screen will carbon up after a while, and restrict flow, but is a simple maintenance item if you remember to do it. If you don't want to bother with that, you could punch out just the screen.
This is what peaked my curiosity when I read the manual. I like the quiet sound of the exhaust though and want it in, but the experiment was fun to try
The easy way to get more power and speed is a bike already designed to do just that, 250, 450, 1000, 1800 cc bikes.
Stfu
Thanks Big Balls! Lol. Seems most people aren’t getting the point of an “experiment” and think I’m looking to turn this bike into a 100mph bike
Your speed test is fine, but I think you should measure a mile distance and then run that mile for time. That way your tests accomodate for power and a different torque curve.
Makes sense
Owh. Spark arrestor also acts as screen from outside debris.
Honda runs everything super lean from the factory. Opening the exhausts and intake probably just best prep for mild jetting. That’s really the best way to get better top speed or power from Honda. If yo get any leaner, your pipes will blue and you’ll lose power. Generally.
Not just Honda, all manufacturers run the street legal stuff as lean as possible to pass EPA regulations.
In all honesty with the cost of aftermarket modern FI intake kits, air box or filter kits and aftermaket exhaust and aftermarket ecm or reflashing the stock ecm not to mention for street use your bike will no longer actually be legal if you need more power just move up to a bike that stock fills your needs.
Will probably be no more expensive, be actually street legal and not void your warranty.
Say the trail 125 properly modded for instance would actually end up being only a few hundred dollars less than a street legal CRF 300L which would have much better power stock than the trail 125 modded.
Buy the right bike to begin with is the best move.As far as long term reliability and minimum issues usually the more stock it is the better off you are as an owner.
Change the sprocket size 16/ 37
I don’t think it would even move with that combo
Enjoyed the video! It's the little things that count. Why would people get angry?
One thing you can do...make sure at wide open throttle the carb slide completely clears the venturi.
Some bike the spring will coil bind prior to slide clearing venturi
that'd make sense on a carbureted bike
If you wanted it to adapt to the change, I'd ride 10-20 miles to let the ecu relearn the optimal AFR then try the top speed run. Just my 2¢
It probably will add a bit of top end after riding it more uncorked, just idling won't make the ecu adapt the fuel map like riding would
agreed, I rode for about two miles and knew it wouldn't be enough to let the ecu adapt to the change, but didn't plan to keep it out anyways. More of a test of curiosity.
I guess they put a different model muffler on the Australian CT125 vs the US Trail125... My CT125 doesn't have that removable piece at the end of the muffler body to unbolt.. it's a welded one-piece muffler body.
i thought the same as you did. now i wonder if you just cut the screens out and let the pipe on it.
Exhaust back pressure on any four stroke engine increases the power range, so instead of getting majority power at lower rpm you get power right through to high rpm. The only thing that makes a vehicle go faster is gearing.
You need to add more airflow and more fuel when you relieve the back pressure you just need to raise the fuel pressure up a pound or so you'll get that mile an hour back
It might be related to backpressure and scavenging in the exhaust. Backpressure is when the exhaust flows (typically) down the center of the exhaust, but air flows around the edges back towards the manifold in reverse. You increase backpressure by removing the arrester. But also, the factory design might include some induced scavenging of exhaust, so that the restricted flow actually creates a low pressure that "sucks" the exhaust out more efficiently. Don't know if either is true here, but those could be contributing factors.
Exhaust dynamics are so complicated and counter intuitive that you really need to understand them or you just make it worse most of the time. Better yet, leave it to the professionals, even though I've heard plenty of people tell me that aftermarket cans and such usually reduce power unless it's a complete header system from a manufacturer with a racing background. And then some people just think it's faster if it's louder.
Louder definitely “feels” faster. Agreed
Back pressure is much more a 2 stroke thing, you need it so when kids remove the baffle they often loose performance. The baffle on a four stroke is about sound suppression and shouldn't make much difference
@@nickcarter9538 someone was almost talking like this wasn't too stroke probably a lot of people don't really know and they start using terminology they don't know anything about just doesn't have scavenging ports it has a port for the exhaust and a port for the intake valve
Thank you for the video. I got mt CT 125 2 days ago after a 10 month wait! It is SO cool. We have lots of off road and truck trails here but I also live on a paved mountain rode with 2 miles of it at a 5% grade going 6 miles, (flat) to the nearest town. I am hoping that wont be too much for the bike. Any thoughts? we will find out soon.
how'd it do?
Very well done
Thanks!
If it flows more air without the arrest or, you’d then also need to remap the injector to deliver more fuel. Otherwise, you’ve leaned out an already lean motor which will always result in less power.
Just curious John. What was your out-the -door cost on the bike in Florida?
Mine was 4200.00
Just installed a windshield/windscreen on my BUDDY 50 scooter ..GAINED 5 MPH on TOP END with windshield ! .plus much less wind noise ..warmer in cool weather ..win win 👍
I wouldn't bother trying to get a few mph more out of the T125, it's not logical, like trying to soup up a farm tractor to go a little faster. I owned a '63 and still have a 68 CT-90. They would only go 45+ mph. I always wished they had conventional foot shift and hand clutch. I wonder if the supplied battery needs to be helped with a "battery minder" to keep it in good shape and reliable to start the bike if you ride a few miles once per week. Also wonder whether kick starting will work when battery is not able to start with electric starter.
The injection version of the honda z50 can be started with a flat battery.
(otherwise a kicker would not be of much use)
If you do this spark arrestor mod do not operate it in any forest or desert area because when they track you down after the fire you start and you receive the massive life long financial ruin that follows you will learn the consequences .
good thing it went back in as soon as I hit stop on my gopro. I wish everyone would watch the whole thing before posting their fears of me starting a forest fire...
@@John5XR John it is not fears of you starting a forest fire. If the video encourages 1000 other CT125 owners take their spark arrestors out then maybe one might accidentally start a forest fire. As I write this over 92k have watched the video. It isn't inconceivable that a few thousand might proceed to remove or modify the arrestor to get the throatier exhaust growl. It did sound good - but with UA-cam stardom comes great responsibility! 😁
Honda dealer say engine is tuned to the exhaust
Should do a 0 to 30 mph test
You need to read the plug ,i bet it's runing lean . you need to free up air cleaner and up size main jet. Or change fuel map if its injected.
plug read would be interesting to do, but since it's injected the only thing I'd be able to change is the fuel map, which I can't even change as I don't have the ability to do that. No biggie, just a simple experiment to see what happened as I've had it help on other bikes (all carbureted though)
Had a two stroke moped in college. The exhaust fell off and it picked up a few mph. The engine would also run backwards.
Love two strokes!
mine is now 1 year old yesterday. and it loves 50 mph. but on good days i have seen 62 mph. and its still 100% stock. its not for from needing a new chain and when i do i'm thinking of going to a 15/ 41 i will have the same top speed. but when i hit hills for a few days in a row i can drop my front sprocket to a 13 or 14 and get more power. but with a stock bore engine i dont see getting anymore power or speed out of it.
Update. i took mine out and it seemed to give me a little more power lower end but the same top speed. and made more noise. so i just cut the screen off and put it back on and same thing more lower end power seemed to hit top speed sooner but still the same. now i'm thinking of cutting the tube off at the mount and see what that might do because it wont have to make 3 trips through the muffler.
In case you never checked it via GPS but the stock speedometer is about 2 mph higher than your actual speed. Everyone on the forums report the same thing. I'm not real surprised the speed didn't change much. Sometimes more back pressure provides better performance. The engine is tuned for a certain amount of back pressure. Of course there are too many variables to be certain. Same wind as before? Exactly? Same wind speed and same direction, exactly? This bike is very susceptible to any small changes like that. Also, when you open the exhaust up, the normal thing to do is you have to increase the breathing (more intake to take advantage of more exhaust). Again, it was a quick test that proved nothing because you didn't increase the airflow to match the new exhaust free-flow and the weather is your biggest factor. But it serves to tell people "don't bother taking out the spark arrestor". (which is illegal in the US anyway.)
I cross-reference all of these test rides with the REVER app, which tracks the ride and provides the top speed achieved. It’s gps based. My Speedo was 1mph slower than the app, close enough for me.
You might not be like me, but when I flipped through the manual and saw a big potential restriction in the pipe that could be removed with a few bolts, there was no way I wasn’t gonna take it out and see what it did. Whether it worked or not, I wanted to see what happened. I’m a racer and a tinkerer, even if the experiment doesn’t work on paper, I find the experience fun and interesting nonetheless.
You say it proved nothing? Absolutely it proved something: that it didn’t help top speed! Lol!
And I’m not worried about legality, as here in Florida we run motorcycles with aftermarket pipes with no issues from the law. If I’m riding in a US forestry or park, yes it is required to have a spark arrestor and I would do so
@@John5XR I installed the opmid speedometer multi-meter so I could set my speedo to read exactly what the GPS says. Also, like most of the guys that got these anemic bikes, I've been changing the gearing which put the speedometer a long ways off so the Opmid makes up for those experiments. I don't know why your speedo reads slower than everyone else's. All cars/trucks, bikes tend to read higher (they say it has something to do with keeping you at the speed limit because everyone speeds a little), but all manufacturers do it and pretty much always have. Like everyone else, mine read almost 2 mph higher than I was going and when I geared it down it was off by at least 5 mph. I hated having to think about what my speed really was all the time when I'm in town, and of course it affects your odometer so your mpg calculations can be way off. BTW, I got 140 mpg yesterday. I've been doing some slow riding while my wife gets her new trike broken in.
So I'm guessing there's no spark arrestor on the Monkey since it's main purpose is on the road?
Curious to know...
No, the Monkey doesn’t have the same spark arrestor setup as the trail.
Riding a lot in the bush up in British Columbia I'd never even think about it. Forest fires are such a huge problem I don't want to be the guy to add to it.
A lot of these small bikes from 50cc up 125cc maybe a little bigger used to have a small diameter piece of pipe welded into the exhaust where it bolts onto the head to restrict them I removed loads of them when I was younger for myself and friends who had bikes, it takes some hammering to get them out but it always had good results but taking out baffles never done anything other than change the noise so take a look.
Is that a 10AE miata in your driveway?
Nice one john,the postmans bike is a legendary Honda,,in Australia thay have mad desert rally on ct110s each year,",the postmans chalenge" ,,,,,,the cat IS a really restrictive unit,,,im gonna cut the cat and leave the muffler on my 2020 grom,,
As it should be, this bike is so useful that it should be celebrated!
Yup, I also heard that a kangaroo wearing a postman's outfit delivers the mail and sez "guday mate" when he delivers that mail.....
@@John5XR we jus got them here,,i like the desert storm colour,,really cool real world bikes,,,yoc can have a shed full of bikes, vut the one you need is the posty,,,lots of ozy deckoutwhith xr 200 tank gard,seat ,rims,if you take ego out of equation its NUMBER 1☝️🌎
@@chuckbowen4334 chuck ,HONESTLY m8,,your nearly as crazy as me,,,my advise??, ride lots✊🍀
Think the ecu has a break in. After a certain mileage the bike will open up and go faster. Be interesting to find out if this is true or not. I've seen videos after a certain mileage the bike will go up to 65 close to 70
I feel this bike has a secret built in top speed limiter honestly
We always took the baffles out on our dirt bikes back in the 70s big difference in power orr put tuned eshaust them lol... 👍🇺🇸
That was my thoughts with this experiment too, but modern fuel injection had other plans.
A modern ecu usually restricts the engine to only make a certain amount of power. Reduces warranty calls and improves their reliability reputation. The days of just turning a screw on the carb are over.
You mite consider cutting the screen end off so it never plugs up.
Yep. You’re right. Honda looks to have done a great job tuning the spark arrestor into the exhaust. That arrestor is a behemoth compared to the other aftermarket exhausts. Wonder if you’ll have any more HP after break-in and first oil change?
It’s a huge restriction, but if you look into the pipe there are other smaller pipes in there as well, kind of like a 6-shooter barrel, it’s weird. Once I saw those I didn’t think there would be a huge flow increase from removing just the spark arrestor, but was curious to try either way. With an aftermarket pipe and ecu reflash, it would probably add a good amount of power and speed to this bike, BUT, I like the super quiet exhaust as I use this bike around the house
Didn't he say he's owned his CT125 for a couple of years now? Ive watch an ass load of videos on these Honda Mini cycles today so I may get what was said, mixed up! Great little machine
The only way to increase speed is to increase rpm. Removing spark arrester (old school baffle) will improve performance, ie 0 to 50 time.
Density altitude also will effect that performance cool morning vs mid afternoon. Probably nominally different but still.
I wish Honda would come out with the sub transmission. The first year they came out with the ct110, they didn't the sub transmission. The next year they did, and you could then ride better off road, and climb any hill and crawl. I still have mine but was hoping the 125 would have that sub transmission. We'll see.
If you ride off road or on BDRs , forest service roads, public lands spark arrestors are required. Regardless of sounds or horsepower gains removing it is not advisable. Many aftermarket exhaust systems include spark arrestors. The reason they are there is for what they name implies which prevents fires . JS.