I’m surprised your videos are JUST NOW coming into my algorithm. For years I’ve scoured YT for the exact topics you’re discussing on your channel and you’re by far the easiest to listen to and the most informative. Perfect blend of knowing what you’re talking about but delivering it in a non-technical manner that easy to understand. Wish I’d found you sooner. Keep it up either way! Cheers.
I'm learning the feel. Rich feels thicker/juicier in midrange, stiff on top, kinda like a clogged catalytic converter. lean feels tinny, thin,hollow in the handlebars. My TC250 was so punchy in midrange for my Vet butt, lowered clip and its more linear, helps me control and roll on throttle easier.
Right on. Sounds like you got a good grasp of it. Using it to tune in the type of the power you are looking for as well. It was kinda hard to make this video because its more of a hands on thats needed to learn the feel and sound. Good job!
@@MasterMotoTv Thanks! Yes sir, I get out to Croom from time to time. Been riding there since like 1997. I also try to camp out there about once a year. Love that place!
@@UpAllNight91 well I just blew up the top end this weekend trying to tune my bike. New top end will be in tomorrow. Are you near Brandon FL? I’d like to take my bike to you and maybe learn a thing or two.
@@MasterMotoTv Hello. I'm located in Parrish which is right up the road. Bummer on the bike blowing up, that sucks. If you need any work done you can reach me at upallnight91@hotmail.com
I like that you mentioned that its also rider preference and that they can be tuned like the tuner app on the f's. People get way too caught up trying to find the magic combo or spark plug color.. lol i know i was one of em. Ditched all that. Just go by feel. Love a meaty midrange especially coming out of corners is really important to me so maybe a tad fat in the mid but main still revs out clean. So mines less linear, more punchy. But i freaking love that fealing, im addicted lol. So perfect for more me.
Also cutting the head the way you did, woke up the bike so much and made jetting considerably easier. Obviously setting the squish isn't mandatory but does make jetting way easier
I can understand that. My YZ125 I actually prefer the ever slightly rich needle used in the 2011 to 2021 over the slightly leaner 2005 to 2010 needle. It gives more throttle control.
i’m not surprised to see that the main jet on the keihin carb has effects at all throttle ranges. i have noticed changes in idling after changing main jet sizes on my ktm.
If one clip groove on the needle is too much of a jump, you can also use little washers, (I make mine), that will allow you to make adjustments lesser than one whole groove. The clip jump is about 1mm (.040"), so a washer at .5mm thick under the clip, (and the same outside diameter of the clip), of the needle will give you half that adjustment.
great sound effects bud lol! i got a really clean 98 yz250 and i installed a lectron carb that just works awesome. i couldnt jet that bike to save my life. think the stock carb was just worn. your vids are great. keep up the good work
Plug readings: I can see your point if you don't know what rpm range you are running at, but it is still a good indicator for other throttle settings, (plus how much oil you are spitting through the exhaust. I like it dry.). But for setting the main jet, plug color and condition work very well with wide open runs and a throttle chop. You should use the manufactures plug, as different brands with supposedly the same what range are different. With that dark plug, it is rich somewhere in the power curve, and losing power. I like to set the main jet last. The YZ 250 (my 2019 model for sure), is very very rich stock. I am, not a fan of the power jet. I say a carb was easier to jet well with out it.
Right. For me I'm not always looking for the perfect burn. Like example the YZ250 with a custom head, I like it a little on the richer side on the crack of the throttle to soften the extremely sharp snap that bike has with a custom head. Not so rich to foul plugs but just enough to change the delivery some. There is room to play around with the mixture to curve the power delivery some, as long as its not too lean that it burns things up or too rich that plugs don't last
hey man im having issues with my 2019 kx250f spitting and sputtering and then shutting off while im riding. i got it on my gopro if you have something i can send it to. i just need some guidance on what it could be!
I usually use JetsRus when I buy jets or carb parts. Might be worth checking out even as a quick reference since they have info like typical jet ranges.
Hello. Looking for the best highest idle while setting the idle mixture works great on 4 strokes. On 2 strokes is a little different because the charge first goes down to the crank area and then makes it way into the combustion chamber there is a delay at low velocities (like during a idle). For the tuner this can feel like it leaves use a huge range that all seems about the same but also 2 strokes when run overly lean they will start to run away and lean free rev. Its not good for the motor. So we can be fooled into thinking thats the best air fuel ratio but its actually starting to lean run away. For me I like to tune the air screw by feeling how it takes little blips of the throttle and how it feels when riding the bike and cracking into the throttle. I dial that in and thats the sweet spot.
@@UpAllNight91 thanks buddy. I’ll play with mine I checked the stock jetting the other day just to verify after my fmf fatty install and it was a 50 pilot 178 main and air screw was around 2 1/4 turns out.
@@UpAllNight91 I know. Manual says stock is 1.75 turns. Haven’t had a minute to mess around and ride to get back to you. Glad everything is good after the hurricane. I have family in Tampa and Ft. Lauderdale and all is well.
@@Aad2797 Yes sir! I found my 2022 at just under one turn. The original over never stuck a tool on it. I'm currently running only 3/4th's on a turn on it.
I run 173 main 40pj 43 pilot on 110 with vforce3 reads apex head cx dome and read spacer. Im at 1090 ft elevation you think thats about correct. Also 32:1 on fuel. Stock exhaust
I put a JD jet kit in my sons 23 yz85. It seems a little too rich with the recommended 148 main and too lean with the 145. Do they make a 146/147 main for the keihin carb? or should I try adjuting the needle with either the 145 or 148?
@@UpAllNight91 yes it came with 2 needles, one for low altitude and one for higher altitude. We are close to sea level and I have the lower altitude needle installed. The throttle response sounded good with the 145 but it was very lean wide open on the stand, wasn't as noticeable on the track but the bike ran hotter than I'm comfortable with. I'm thinking it might be best to try the 148 and lean the needle out by raising the clip. Throttle response sounded a little rich and not as crisp as with the 145. It did seem to clear up some on the track. Though not perfect, this setup did seem better than the stock settings.
@@jonjones8030 ok. Yeah maybe try the richer main and needle one clip leaner. I would focus the main jet testing on the track when its at wide open throttle under load.
I'm getting "pipe bangs" stock reeds new top end 178main 50 pilot i'm at 850 ft 65° fmf exhaust system. Never had this before with the old top end kinda confused. Ive been letting it warm up for the heat cycles. And taking it easy, i was 1.5 turn out on air screw. I think the idle screw might need adjusted lower?
Oh man. Yeah. I'm sure at that altitude it can be very challenging. I don't personally have experience at them altitudes but I do remember hearing from guys who do that having the head rechambered with higher compression sure helps clean things up and makes the jetting easier
I’ll get it. I think your idea of learning what it feels like is smart. I know rich. A decent tune at 6k is crap at 9 or 10k. I can feel that. I did get a high altitude Apex head too.
Ahh right on! I'm sure that head helps majorly. Down here in Florida we are at sea level and that makes it easier except when the summer humidity comes. It gets a little different in the high humidity to get them right on
Hello, a question that you would recommend for a Yamaha YZ 250 2t 2023, I am waiting for a fmf factory fatty and shorty, it is carbureted as standard with a main jet 178, do you recommend that when I put the exhaust, I raise the jet to 180 or 182, thanks in advance, regards
What website are you using or are going through to get the Yamaha YZ 125 manual for free? I am in desperate need of a service manual for a 2002 Yamaha YZ125 . Can any of my brother's here in this group please help me out. Thank you and God bless guys ride safe Brothers!!! 💯💪🙏
Dynos are cool. I use them when I put a cars engine package together. On the dirt for me its more about how it feels and performs on the track than it is getting a good o2 reading and a nice curve that a dyno offers. Plus weather changes and its good to be able to jet it out yourself on the fly when it does.
Question. I got a 03 yz250 making a trip to an Elevation is 0-2000ft. I am getting some spooge out the silencer. Plug is a little wet so I’m know I’m running a little rich. I got v force 3 reeds with Fmf factory pipe and turbine 2 silencer. Done some research and I’m seeing a lot of points to run a 175 main 48 pilot with stock needle 2 clip. I’m currently have stock 178/50 air/mix screw 1 turn out, jetting in at the moment. Any thoughts? Also, run 40.1 yamalube mix and do hill climbing/trail riding
Hello. My wifes yz125 is jetted spot on while leaning towards the leaner side, running 40;1 and she also has spooge coming out of the silencer most of the time. I wont go any leaner because it would be too lean and I wont run less premix either as I don't want the motor to suffer. She just doesn't ride the bike hard enough to keep it cleaned out but its ok the way it is. The bike has 300 hours on the original crank and never fouls a plug. If you are not opening the motor up and keeping some good heat in her they will spooge, that's just how it is. Sure you can go too lean and run less oil but its not healthy for the motor. The spooge doesnt hurt a thing. I'm not saying your not opening her up enough but thought I would cover that just in case. a 175 and 48 with the stock needle on 2nd clip sounds fair to me, I don't see anything wrong with that jetting and sounds like a good starting point. As you go up in elevation you will also need to turn the air screw out to keep it nice and clean running at throttle tip in.
@@UpAllNight91 okay, I’m going back to old riding spots and the bike ran good stock everything on it. Just thought on the Fmf pipe and vforce3 reeds on it now with getting stooge. Every thing I read about is everyone drops sizes when putting a pipe on. Just curious what your thoughts.
@@Drakester55 Right on. The v force doesn't change jetting at all in my experience. PC and FMF pipes don't change the jetting much either but they seem respond better to slightly leaner main jets (usually one size leaner than the stock pipes preferred jetting) to bring out the extra top end performance they have to offer. These are just my experiences with these at least.
@@UpAllNight91 hey, I replaced the mid body gasket on my YZ the other day and noticed the brass where the slide needle goes into the jet mid body is starting to chip/break/crack however to put it apart alittle. I have a picture of it but can’t send it on here. Just curious is that going to affect it at all. Just not seeing anywhere to buy a new jet mid body or how to replace the brass part of housing for the mid body. Any ideas?
I have a 98 cr 250 it will start and run it might run a minute or it might even go 15 minutes then it dies it’s like it runs out of gas any suggestions
Be sure to check that the carb is getting a good flow of fuel and the carbs float bowl is getting filled up nicely. If thats good. I have seen stator coils that work fine when cold but fade away as it warms up and the bike dies. To test it run the bike till it dies. Quickly remove the spark plug and reduce the gap to about 0.012", install plug and see if it will run again and stay running. If it does then your stator is going out.
Ive rebuilt a 83 RM250, it has a stock TM flat slide carb it dont run too good, Im thinking about replacing it with a PWK from a Yam YZ250 is that a good plan? ( The TM dont have an idle screw)
Hello. Nothing wrong with using PWK. I would look for one from like a KTM 125sx (38mm) or a KTM 250sx (36mm) because they dont have the power jet. Since your bike doesnt have the electronics to run the power jet might as well get the PWK that does not have one in there. I dont know what size you are looking for but for some reason KTM used a smaller 36mm on the 250 and the larger 38 on the 125 and 150.
@@aaaaaaaaaaaaaa4151 ok, hmm. I dont have experience with a 83 RM250 but if I was to try and get a PWK 38 to work on it I would start with jetting found on other newer Rm250's with the PWK. Pro circuit has a jetting chart ( www.procircuit.com/jetting-specs.htm ), look at a Rm250's jetting with a PWK and start with that jetting. and then adjust from there,
Im.chasing an issue. 172 main jet fmf fatty kiehin carb 99 yz250.. set float hieght. Still having issues bikes not responive feel rich and slow. New reeds
Hello. I would start with new reeds if they are old. However I am in the process of replacing my wifes YZ125 (317 hours on bike) carburetor. I thought it only needed a new jet block gasket, replaced that and it still runs a little rich on tip in. Nothing I could do to fix it, even jetting would only mask it and cause other jetting issues in other throttle ranges. So I installed my YZ125 carb (120 hours on bike) on her bike and it instantly ran like a brand new bike. Long story short, these carbs needle can wear into the hole the needle goes into (atomizer) after many hours of use. It will cause a richness. And this part is not replaceable, the only fix is a new carb. Not saying thats what you need, just sharing what I'm facing and what I found the fix was. About to do a video on this actually.
hi . i have a problem with closed gas to 15 percent .... its like not running permanent its like going back and forth all the time .. sorry for bad english im from germany =)
Is my jet needle too rich if i slowly rev up my bike then when i get around 1/4 to 3/4 throttle it starts sputtering and skipping but my clip on the needle is already on the top position what should i do
@@UpAllNight91 its a 2000 yz125 and it runs good when riding it but she does file the 9 spark plug after a few hours of hard riding and my pilot jet and main jet are good
@@UpAllNight91 then whenever i put a hotter spark plug in it skips less and runs better but not perfect yet it still skips and another thing is that the 8 plug is tan when i use it
@@braydenhoffman ok. That has the mikuni carburetor right? There are two issues that can pop up on that carb that can cause it to run rich in the needle area of the fueling. I had the same issue with the wifes bike and fixed it. Here is a link to the video on it ua-cam.com/video/Ti1d6TOdlGg/v-deo.html
stock pwk on my RM 250 2003...runs great but will not idle and it loads up and dies after about 10 seconds at idle. Dropped from a 48 pilot all the way to a 38 and it still never leans out even with the air screw 3 turns out. Fresh top end and 185lbs of compression with new Boyesen reeds. 162 main, 6.5 slide, 50 PJ and stock needle on the 2nd clip. All circuits are clear, new midbody gasket, choke sealing the well. I can get it to idle for a little bit and put the choke on and it didn't effect the rpm at ALL?! Spits a lot of spooge out the pipe but runs amazing through the rev range....just will not idle.
@@RadioReprised Ok, I ask because cast iron sleeves can cause all kinda of issues when not installed correctly. Is the powervalve closing completely, center and side sub ports?
I have yz125 2003 an it has 35 for pilot seems to small but bike running dam good so should i leave it alone??? My spark plug is black on one side every time ??? Why
If its running good you can be good. But sometimes a little trial and error and you may find you like one better than the other. Maybe try a 37.5 just to see, and or try the leaner one too. I often cant leave good enough alone till I truly see what the other options have to offer lol
@@UpAllNight91 im gonna try that when I get my bike back from my mechanic I like what u said im try 37.5 an IL try leaner one too see how it does il keep u updated bro.
My pilot is 63 an after a few rides its getting clogged I put a filter strainer in my gas tanks to help bike still runs good even if pilot clogged u have any suggestions
You can check for play in the main crank bearings with the cylinder off. You can also just remove the stator cover and grab the flywheel and check the tightness of the crank bearings there.
If the bearing on the clutch side has up and down play you will be able to feel it on the flywheel as well. It will rock up and down as you try to move the flywheel up and down.
@@sethmacgillivary1281 overly rich washes the lube off the cylinder wall. The fuel needs to be lean enough to vaporize or atomize to drop the lube out of it,
This is a pain to do, 2 strokes are so old school. Get a 4 stroke with EFI, you will be a happier rider. No wasted time on old carbs. Didn't anyone tell you carbs are bad? :>
On a 4 stroke I agree, EFI is best. Owned many of them and wont own a 4 stroke carbed bike. But on a 2 stroke a carb can't be beat by EFI. The 1 HP lost in power due to the extra power pulled from the stator to run the fuel pump and extra electronics is not made up in the end and the motor doesn't even feel any better. They are two totally different animals
Thank you for taking the time to do these carb videos. As a new rider that works on his bike, I find them extremely helpful!
Ahh nice! Glad to hear this!
I’m surprised your videos are JUST NOW coming into my algorithm.
For years I’ve scoured YT for the exact topics you’re discussing on your channel and you’re by far the easiest to listen to and the most informative. Perfect blend of knowing what you’re talking about but delivering it in a non-technical manner that easy to understand.
Wish I’d found you sooner.
Keep it up either way!
Cheers.
Ahh Glad you found it!. Thanks and welcome aboard!
Gave me all the info I need to get going on tuning my yz250. Thank you so much!
Right on! Glad it was of help!
@@UpAllNight91 upallnite's channel - yz125\250 2t ex race team mechanic
I have an 09 yz125, your channels an amazing resource! Thank you
Your welcome! Glad to hear that!
I'm learning the feel. Rich feels thicker/juicier in midrange, stiff on top, kinda like a clogged catalytic converter. lean feels tinny, thin,hollow in the handlebars. My TC250 was so punchy in midrange for my Vet butt, lowered clip and its more linear, helps me control and roll on throttle easier.
Right on. Sounds like you got a good grasp of it. Using it to tune in the type of the power you are looking for as well. It was kinda hard to make this video because its more of a hands on thats needed to learn the feel and sound. Good job!
Absolutely amazing video!! Thank you for the help and knowledge brother
do you go to Croom?
@@MasterMotoTv Thanks! Yes sir, I get out to Croom from time to time. Been riding there since like 1997. I also try to camp out there about once a year. Love that place!
@@UpAllNight91 well I just blew up the top end this weekend trying to tune my bike. New top end will be in tomorrow. Are you near Brandon FL? I’d like to take my bike to you and maybe learn a thing or two.
@@MasterMotoTv Hello. I'm located in Parrish which is right up the road. Bummer on the bike blowing up, that sucks. If you need any work done you can reach me at upallnight91@hotmail.com
I like that you mentioned that its also rider preference and that they can be tuned like the tuner app on the f's. People get way too caught up trying to find the magic combo or spark plug color.. lol i know i was one of em. Ditched all that. Just go by feel. Love a meaty midrange especially coming out of corners is really important to me so maybe a tad fat in the mid but main still revs out clean. So mines less linear, more punchy. But i freaking love that fealing, im addicted lol. So perfect for more me.
Also cutting the head the way you did, woke up the bike so much and made jetting considerably easier. Obviously setting the squish isn't mandatory but does make jetting way easier
I can understand that. My YZ125 I actually prefer the ever slightly rich needle used in the 2011 to 2021 over the slightly leaner 2005 to 2010 needle. It gives more throttle control.
Yes getting the head right surely sharpens up the jetting, I agree with that
i’m not surprised to see that the main jet on the keihin carb has effects at all throttle ranges. i have noticed changes in idling after changing main jet sizes on my ktm.
For sure. I also notice the pilot effects the full throttle as well.
Yep it’ll give you a rich bog when you wick the throttle fully open then u know you gotta drop a pilot size
If one clip groove on the needle is too much of a jump, you can also use little washers, (I make mine), that will allow you to make adjustments lesser than one whole groove. The clip jump is about 1mm (.040"), so a washer at .5mm thick under the clip, (and the same outside diameter of the clip), of the needle will give you half that adjustment.
Thats a good tip!
great sound effects bud lol! i got a really clean 98 yz250 and i installed a lectron carb that just works awesome. i couldnt jet that bike to save my life. think the stock carb was just worn. your vids are great. keep up the good work
Thanks man! Yeah I have run into a few carbs that just cant get right and I gotta write them off as age. 1998 YZ250, cool bike
Pretty common sense breakdown. Great video!
Thanks!
excellent video sir!
Thank you!
Thank you, another great one!!
Thanks! And thanks for watching!
Plug readings: I can see your point if you don't know what rpm range you are running at, but it is still a good indicator for other throttle settings, (plus how much oil you are spitting through the exhaust. I like it dry.). But for setting the main jet, plug color and condition work very well with wide open runs and a throttle chop. You should use the manufactures plug, as different brands with supposedly the same what range are different. With that dark plug, it is rich somewhere in the power curve, and losing power. I like to set the main jet last. The YZ 250 (my 2019 model for sure), is very very rich stock. I am, not a fan of the power jet. I say a carb was easier to jet well with out it.
Right. For me I'm not always looking for the perfect burn. Like example the YZ250 with a custom head, I like it a little on the richer side on the crack of the throttle to soften the extremely sharp snap that bike has with a custom head. Not so rich to foul plugs but just enough to change the delivery some. There is room to play around with the mixture to curve the power delivery some, as long as its not too lean that it burns things up or too rich that plugs don't last
Does the transmition oil u put in ur motor lube ur crankshaft or does the oil u mix with ur gas lube ur crankshaft
The transmission oil on a 2 stroke bik only lubes the trans and clutch. The premix in the gas lubes the crank and piston.
Another great video!!!
Thanks!👍
hey man im having issues with my 2019 kx250f spitting and sputtering and then shutting off while im riding. i got it on my gopro if you have something i can send it to. i just need some guidance on what it could be!
Hello. Sure. You can email it to upallnight91@hotmail.com
I usually use JetsRus when I buy jets or carb parts. Might be worth checking out even as a quick reference since they have info like typical jet ranges.
JetsRus, Will check it out! Thanks
When setting your air screw are you letting it idle and listen for the fastest idle or 1.5 turns out and tune for the power you want while riding.
Hello. Looking for the best highest idle while setting the idle mixture works great on 4 strokes. On 2 strokes is a little different because the charge first goes down to the crank area and then makes it way into the combustion chamber there is a delay at low velocities (like during a idle). For the tuner this can feel like it leaves use a huge range that all seems about the same but also 2 strokes when run overly lean they will start to run away and lean free rev. Its not good for the motor. So we can be fooled into thinking thats the best air fuel ratio but its actually starting to lean run away. For me I like to tune the air screw by feeling how it takes little blips of the throttle and how it feels when riding the bike and cracking into the throttle. I dial that in and thats the sweet spot.
@@UpAllNight91 thanks buddy. I’ll play with mine I checked the stock jetting the other day just to verify after my fmf fatty install and it was a 50 pilot 178 main and air screw was around 2 1/4 turns out.
@@Aad2797 How 2-1/4 is pretty lean on the air screw. Stock they come at around 1 turn.
@@UpAllNight91 I know. Manual says stock is 1.75 turns. Haven’t had a minute to mess around and ride to get back to you. Glad everything is good after the hurricane. I have family in Tampa and Ft. Lauderdale and all is well.
@@Aad2797 Yes sir! I found my 2022 at just under one turn. The original over never stuck a tool on it. I'm currently running only 3/4th's on a turn on it.
I run 173 main 40pj 43 pilot on 110 with vforce3 reads apex head cx dome and read spacer. Im at 1090 ft elevation you think thats about correct. Also 32:1 on fuel. Stock exhaust
Hello. Considering the elevation that sounds fairly close.maybe a little lean on the pilot but not too bad.
I put a JD jet kit in my sons 23 yz85. It seems a little too rich with the recommended 148 main and too lean with the 145. Do they make a 146/147 main for the keihin carb? or should I try adjuting the needle with either the 145 or 148?
Hello. They dont have jets in the middle like that. You can try the needle clip. Did this JD kit come with its own needle?
@@UpAllNight91 yes it came with 2 needles, one for low altitude and one for higher altitude. We are close to sea level and I have the lower altitude needle installed.
The throttle response sounded good with the 145 but it was very lean wide open on the stand, wasn't as noticeable on the track but the bike ran hotter than I'm comfortable with.
I'm thinking it might be best to try the 148 and lean the needle out by raising the clip. Throttle response sounded a little rich and not as crisp as with the 145. It did seem to clear up some on the track. Though not perfect, this setup did seem better than the stock settings.
@@jonjones8030 ok. Yeah maybe try the richer main and needle one clip leaner. I would focus the main jet testing on the track when its at wide open throttle under load.
I'm getting "pipe bangs" stock reeds new top end 178main 50 pilot i'm at 850 ft 65° fmf exhaust system. Never had this before with the old top end kinda confused. Ive been letting it warm up for the heat cycles. And taking it easy, i was 1.5 turn out on air screw. I think the idle screw might need adjusted lower?
I would check the power valve, make sure its closing at low RPM's
Been struggling with mine for awhile. I’m at 6k ft and ride up to 10k ft. I’m gonna try some Suzuki needles.
Oh man. Yeah. I'm sure at that altitude it can be very challenging. I don't personally have experience at them altitudes but I do remember hearing from guys who do that having the head rechambered with higher compression sure helps clean things up and makes the jetting easier
I’ll get it. I think your idea of learning what it feels like is smart. I know rich. A decent tune at 6k is crap at 9 or 10k. I can feel that. I did get a high altitude Apex head too.
Ahh right on! I'm sure that head helps majorly. Down here in Florida we are at sea level and that makes it easier except when the summer humidity comes. It gets a little different in the high humidity to get them right on
Dirtbike bogs out then dies when riding? What's my issue
Could be so many things. I would start by removing the fuel like and making sure the fuel going from the tank to the carb is flowing fast and free.
What’s considered winter in Florida? I’m living in SC last 4 years, but lived in MI most of my life.
70 degress is winter here in Florida lol. But the cool air really doesnt start messing with our jetting till it gets close to and before 50 degrees.
If I run my bike rich I know it wouldn’t run great, but would it harm anything besides fouling plugs?
Depends on how rich. A little rich wont hurt anything but overly rich can wash the cylinder walls of lubrication and wear out the motor quicker.
Hello, a question that you would recommend for a Yamaha YZ 250 2t 2023, I am waiting for a fmf factory fatty and shorty, it is carbureted as standard with a main jet 178, do you recommend that when I put the exhaust, I raise the jet to 180 or 182, thanks in advance, regards
Hello. Usually aftermarket performance pipes seem to like about a main jet size leaner than the stock pipe.
I recommend JD jetting Kitt
What website are you using or are going through to get the Yamaha YZ 125 manual for free? I am in desperate need of a service manual for a 2002 Yamaha YZ125 . Can any of my brother's here in this group please help me out. Thank you and God bless guys ride safe Brothers!!! 💯💪🙏
Hello. You can download your manual for free on this link... library.ymcapps.net/library/om/app/index.html?baseCode=6150&langId=02
@UpAllNight91 thank you so much brother. you are a lifesaver man!!! 💯💪🙏
Dyno tune it and save yourself the emotions of thinking is it perfect.
Dynos are cool. I use them when I put a cars engine package together. On the dirt for me its more about how it feels and performs on the track than it is getting a good o2 reading and a nice curve that a dyno offers. Plus weather changes and its good to be able to jet it out yourself on the fly when it does.
sick bike bro!!! 👌🤌
Thanks!😁
I put a new carburetor for my bike did what FMF said but when I run the fuel out of the carburetor it rev super high what should I be looking at
Hello. When you say "run the fuel out" do you mean shutting the gas off and running the carb dry?
why do you put duct tape on the sub frame above the chain?
My boot likes to wear away the weld in the sub frame right there. The tape kinda keeps that from happening. A cheap quick fix lol
Question. I got a 03 yz250 making a trip to an Elevation is 0-2000ft. I am getting some spooge out the silencer. Plug is a little wet so I’m know I’m running a little rich. I got v force 3 reeds with Fmf factory pipe and turbine 2 silencer. Done some research and I’m seeing a lot of points to run a 175 main 48 pilot with stock needle 2 clip. I’m currently have stock 178/50 air/mix screw 1 turn out, jetting in at the moment. Any thoughts? Also, run 40.1 yamalube mix and do hill climbing/trail riding
Hello. My wifes yz125 is jetted spot on while leaning towards the leaner side, running 40;1 and she also has spooge coming out of the silencer most of the time. I wont go any leaner because it would be too lean and I wont run less premix either as I don't want the motor to suffer. She just doesn't ride the bike hard enough to keep it cleaned out but its ok the way it is. The bike has 300 hours on the original crank and never fouls a plug. If you are not opening the motor up and keeping some good heat in her they will spooge, that's just how it is. Sure you can go too lean and run less oil but its not healthy for the motor. The spooge doesnt hurt a thing. I'm not saying your not opening her up enough but thought I would cover that just in case. a 175 and 48 with the stock needle on 2nd clip sounds fair to me, I don't see anything wrong with that jetting and sounds like a good starting point. As you go up in elevation you will also need to turn the air screw out to keep it nice and clean running at throttle tip in.
@@UpAllNight91 okay, I’m going back to old riding spots and the bike ran good stock everything on it. Just thought on the Fmf pipe and vforce3 reeds on it now with getting stooge. Every thing I read about is everyone drops sizes when putting a pipe on. Just curious what your thoughts.
@@Drakester55 Right on. The v force doesn't change jetting at all in my experience. PC and FMF pipes don't change the jetting much either but they seem respond better to slightly leaner main jets (usually one size leaner than the stock pipes preferred jetting) to bring out the extra top end performance they have to offer. These are just my experiences with these at least.
@@UpAllNight91 hey, I replaced the mid body gasket on my YZ the other day and noticed the brass where the slide needle goes into the jet mid body is starting to chip/break/crack however to put it apart alittle. I have a picture of it but can’t send it on here. Just curious is that going to affect it at all. Just not seeing anywhere to buy a new jet mid body or how to replace the brass part of housing for the mid body. Any ideas?
@@Drakester55 Hmm. Can you email the picture to upallnight91@hotmail.com . Sometimes the only fix is a new carb body but would like to see a pic.
I have a 98 cr 250 it will start and run it might run a minute or it might even go 15 minutes then it dies it’s like it runs out of gas any suggestions
Be sure to check that the carb is getting a good flow of fuel and the carbs float bowl is getting filled up nicely. If thats good. I have seen stator coils that work fine when cold but fade away as it warms up and the bike dies. To test it run the bike till it dies. Quickly remove the spark plug and reduce the gap to about 0.012", install plug and see if it will run again and stay running. If it does then your stator is going out.
Ive rebuilt a 83 RM250, it has a stock TM flat slide carb it dont run too good, Im thinking about replacing it with a PWK from a Yam YZ250 is that a good plan? ( The TM dont have an idle screw)
Hello. Nothing wrong with using PWK. I would look for one from like a KTM 125sx (38mm) or a KTM 250sx (36mm) because they dont have the power jet. Since your bike doesnt have the electronics to run the power jet might as well get the PWK that does not have one in there. I dont know what size you are looking for but for some reason KTM used a smaller 36mm on the 250 and the larger 38 on the 125 and 150.
@@UpAllNight91 Any suggestion for the jets & needle? thanks for your help!!
@@aaaaaaaaaaaaaa4151 Are you thinking of going with the 36 or 38?
@@UpAllNight91 38mm
@@aaaaaaaaaaaaaa4151 ok, hmm. I dont have experience with a 83 RM250 but if I was to try and get a PWK 38 to work on it I would start with jetting found on other newer Rm250's with the PWK. Pro circuit has a jetting chart ( www.procircuit.com/jetting-specs.htm ), look at a Rm250's jetting with a PWK and start with that jetting. and then adjust from there,
I like your decal kit. Where did you get it?
decallab.com/ you can email them and ask for all their designs for your bike. Its like over 100, you will find it in there.
Im.chasing an issue. 172 main jet fmf fatty kiehin carb 99 yz250.. set float hieght. Still having issues bikes not responive feel rich and slow. New reeds
Hello. I would start with new reeds if they are old. However I am in the process of replacing my wifes YZ125 (317 hours on bike) carburetor. I thought it only needed a new jet block gasket, replaced that and it still runs a little rich on tip in. Nothing I could do to fix it, even jetting would only mask it and cause other jetting issues in other throttle ranges. So I installed my YZ125 carb (120 hours on bike) on her bike and it instantly ran like a brand new bike. Long story short, these carbs needle can wear into the hole the needle goes into (atomizer) after many hours of use. It will cause a richness. And this part is not replaceable, the only fix is a new carb. Not saying thats what you need, just sharing what I'm facing and what I found the fix was. About to do a video on this actually.
hi . i have a problem with closed gas to 15 percent .... its like not running permanent its like going back and forth all the time .. sorry for bad english im from germany =)
Hello. Which bike and which carburetor?
@@UpAllNight91yamaha dt125 r carb is 32 tmx mikuni
@@UpAllNight91 also got athena 170 ccm on it .. .
@@sebastianclauss4537 Can you email me a video of it doing this? Send to upallnight91@hotmail.com
How does weather change mess with jetting
colder air is more dense, which that will lean the mixture. Which will require richer jetting.
@@UpAllNight91 does dense mean thinner or thicker
@@JackMacdonald-ih3ht Denser is thicker. More oxygen in the same volume of air.
Is my jet needle too rich if i slowly rev up my bike then when i get around 1/4 to 3/4 throttle it starts sputtering and skipping but my clip on the needle is already on the top position what should i do
It starts skipping and sputtering at 1/4 throttle if i slowly rev it up in neutral
@@braydenhoffman Hello. What make and model? How does it run when riding? do it only do this in neutral or does it feel ok when in gear?
@@UpAllNight91 its a 2000 yz125 and it runs good when riding it but she does file the 9 spark plug after a few hours of hard riding and my pilot jet and main jet are good
@@UpAllNight91 then whenever i put a hotter spark plug in it skips less and runs better but not perfect yet it still skips and another thing is that the 8 plug is tan when i use it
@@braydenhoffman ok. That has the mikuni carburetor right? There are two issues that can pop up on that carb that can cause it to run rich in the needle area of the fueling. I had the same issue with the wifes bike and fixed it. Here is a link to the video on it ua-cam.com/video/Ti1d6TOdlGg/v-deo.html
stock pwk on my RM 250 2003...runs great but will not idle and it loads up and dies after about 10 seconds at idle. Dropped from a 48 pilot all the way to a 38 and it still never leans out even with the air screw 3 turns out. Fresh top end and 185lbs of compression with new Boyesen reeds. 162 main, 6.5 slide, 50 PJ and stock needle on the 2nd clip. All circuits are clear, new midbody gasket, choke sealing the well. I can get it to idle for a little bit and put the choke on and it didn't effect the rpm at ALL?! Spits a lot of spooge out the pipe but runs amazing through the rev range....just will not idle.
Hmm, does it have a nickle plated cylinder or a sleeve?
@@UpAllNight91 stock bore.
@@RadioReprised Ok, I ask because cast iron sleeves can cause all kinda of issues when not installed correctly. Is the powervalve closing completely, center and side sub ports?
@@UpAllNight91 Yes, but I should say it's 90 to 100 degrees here. I am ordering a 32 and 35 pilot and will try again! Thanks for the thoughts!
@@RadioReprised Oh yeah, hot here too
I have yz125 2003 an it has 35 for pilot seems to small but bike running dam good so should i leave it alone??? My spark plug is black on one side every time ??? Why
If its running good you can be good. But sometimes a little trial and error and you may find you like one better than the other. Maybe try a 37.5 just to see, and or try the leaner one too. I often cant leave good enough alone till I truly see what the other options have to offer lol
@@UpAllNight91 im gonna try that when I get my bike back from my mechanic I like what u said im try 37.5 an IL try leaner one too see how it does il keep u updated bro.
@@michaelgarland579 Yes Sir!👍
My pilot is 63 an after a few rides its getting clogged I put a filter strainer in my gas tanks to help bike still runs good even if pilot clogged u have any suggestions
@@michaelgarland579What are you finding clogging it? anything floating around the float bowl?
How can I inspect the main bearings in my yz 125 without splitting cases just taking top end off
You can check for play in the main crank bearings with the cylinder off. You can also just remove the stator cover and grab the flywheel and check the tightness of the crank bearings there.
@@UpAllNight91 will the flywheel have play if my clutch side main bearing is bad?
If the bearing on the clutch side has up and down play you will be able to feel it on the flywheel as well. It will rock up and down as you try to move the flywheel up and down.
@@UpAllNight91 Ohhh ok have u ever had one go out on a yz 125 and feel it like that
@@UpAllNight91 if my flywheel has no play is it still possible my crank bearings are bad?
If I run my bike to rich can it cause problems?
Depends on how rich. A little rich wont hurt anything but overly rich can wash the cylinder walls of lubrication and wear out the motor quicker.
@@UpAllNight91 would overly rich give cylinder more lubricant??
@@sethmacgillivary1281 overly rich washes the lube off the cylinder wall. The fuel needs to be lean enough to vaporize or atomize to drop the lube out of it,
Where’d you get them graphics?
decallab.com/ if you email them and ask for all the graphics they have for your bike it will be in that list. Theres like over 100 in there lol
This is a pain to do, 2 strokes are so old school. Get a 4 stroke with EFI, you will be a happier rider. No wasted time on old carbs. Didn't anyone tell you carbs are bad? :>
On a 4 stroke I agree, EFI is best. Owned many of them and wont own a 4 stroke carbed bike. But on a 2 stroke a carb can't be beat by EFI. The 1 HP lost in power due to the extra power pulled from the stator to run the fuel pump and extra electronics is not made up in the end and the motor doesn't even feel any better. They are two totally different animals
Some of us mechanically minded people geek out and actually enjoy tinkering and tuning bikes til that 2 stroke absolutely barks!!!
@@bobbysteffan2507 Yeah, I love knowing my bike runs as good as it does because I took the time to get it all dialed in.
Yeah, lame. 😕 👎
It’s a old school manly preference 💪🏾