And the Hip bone is connected to the Thigh bone . When I was young a 5 hp was the boss we had a big dirt field behind our school it had humps,bumps and a couple small jumps and when it rained that was a whole different experience just Fun Fun FUN !!! Try riding like that on school property now days their were six of us full time riders we cut lawns ,washed and waxed cars ,pulled weeds collect bottles and anything job we could to buy gas and parts ,I remember having to buy a few cables , no helmets or safety gear just sun glasses and a backwards ball cap those were the days .
Joel Boley Hey there I see your Massey Harris sign I have an MH 22 great tractor right now it's not running it sat to long and it won't turnover and needs new tires ,and I have an old MH swather with wood spokes on the 10 ft header with drapers and lots of belts that was my first swather and l sold my pto MH bailer a while back it made nice 85 lbs bails ,I went to NH bailers 2 and 3 wire bailers 100lbs on the 2 wire and up to140 lbs on 4 th crop alfalfa with the 3 wire also I have a NH 2 twine and a JD 2 wire bailer , nothing beats a farm and ranch life !! Thanks TANK
@@tanksoldier9770 Massey Harris made good machinery back in the day.... We have a MH 444, three MH 30's two of which run and one that the engine is stuck, two MH 44's, and a MH 44 special. Good ol rake and baler tractors..... We do mostly hay and cattle farming. Wouldn't trade farm life!!!!
i think the coolest thing about UA-cam is that i have been able to watch you guys go from being one of the few vids on about minibikes and modding them to being a growing industry. And to see it be able to support your hobby, and friends you have made.. truly inspiring. From a guy you never met, on the other side of the U.S., keep up the good work.
I'd have to agree. The thing is suckin the bowl dry over and over again. They should put the old flywheel back on too. Seems like the heavier flywheel is being accelerated with enough force to sheer the keys constantly.
@@izzyplusplusplus1004 where exactly do you drill? The outside of the carb where the gas enters, or the inside seat? Just curious haven't thought about trying it.
Love old flatheads ;) Your problem with the flywheel is easy. The key wont hold the flywheel, its just for easy timing. The crank is tapered and the wheel is fasten on the taper. The taper can have bad fit to the flywheel and then you need to take some valve grinding paste and grind the flywheel to the crank. You will see at the surface when you have grind enough. :) The best thing with mondays and wednesdays is carsandcameras! :)
I've worked professionally in my own small engine repair business for over 35 years and i can say without a doubt that the flywheel must be installed with an impact with the special tool or tighten it much more with the hammer than what I've witnessed you do. Also the starter clutch has been a problem on briggs engines. the trick is to polish the part of the crankshaft that inserts into the clutch, put a drop of oil on the fabric wick in the bottom of the hole on the clutch and clean the channels for the ball bearing in the housing. They can stick in the "sling out position". Also there is no rev limiter. The jetting may be too rich..........that's what it sounded like to me or possibly valve float.
The starter clutch/ratchet is a serviceable part. Use a bladed screwdriver and pop the black rubberized cap off, there will be 6 steel ball bearings inside put those aside and lift the ratchet out. use a piece of wire and push the felt dust cap out of the ratchet and clean the inside with degreaser and emery paper if needed and put the dust cap back in. give everything a good clean with degreaser and reassemble the clutch taking care to be clean. Before mounting it back on the crank use a piece of fine emery paper to clean up the crankshaft. It is debated in the industry whether you grease or leave the clutch dry, I personally run them dry as brand new OEM parts come dry.
If the ratchet assembly is dragging you may have a bur on the crankshaft end. Try polishing the shaft stem. Or if you hit it with a hammer it's mushrooomed....
the concept inside the clutch is to let the balls move freely and the centrifugal force in running engine keep this balls away from the ratchets , putting oil will reduce this movement and with sum dirt that will be a good way to loose the clutch and the pully and in sum case the crankshaft.
John and ike, that starter clutch has to be super tight! You have to hold the flywheel with a strap or a bar on the find, then tighten the clutch ad tight as you can get it. As I have a small engine shop, I have the flywheel holder and wrench for the clutch, and a cup wrench I can use a impact to tighten the clutch. That cast iron flywheel has a lot of mass that the clutch had to retain. Also be sure to have the steel cup washer on there also.
Yup and the washer has to be the right way. I wouldnt use an impact itll snap the crank but the surfaces also have to be smooth and clean no burs or grease! Lap it with compound if you have to antiseize works in a pinch. Iv ran them without keys no problem its really just there to position it.
The following video features activities performed in controlled environments by knowledgeable persons. DO NOT attempt to duplicate, re-create, or perform the same or similar activities at home, as personal injury or property damage may result. CARS AND CAMERAS, the persons shown in this video and ANY CONTRIBUTOR, ARE NOT LIABLE FOR ANY such injury or damage. ALL CARSANDCAMERAS CONTENT IS FOR ENTERTAINMENT PURPOSES ONLY.
I hope y'all dnt ever run out of stuff to do cuz y'all make my Mondays so much better n I wanna say thank you iv learned so much from you guys and have had a lot of my own fun because of you thank u again
You guys are making me want to get another old Briggs and Stratton Mini bike. I had a bunch of old go carts from the 70s and sold them but Im going to find one of these and buy it.
This video was awesome to watch! It just goes to show how easy C&C can overcome so many obstacles. I like learning from you guys! It might have taken all day but you guys have a sweet running mini bike now!
If you're shearing keys left and right, that means the flywheel's and crank's tapers are not mating and locking together properly. You need to get some valve lapping compound and lap the 2 together. The key doesnt do anything to hold the flywheel in place, it is ONLY for alignment for timing. You need good mating tapers. And, get yourselves a piston stop that screws into the spark plug hole so you can torque that nut properly.
Sounds very much like valve float...if you buy aftermarket heavier springs specifically designed for the Briggs it should stop that. I think the predator springs were either too short or not strong enough to get those valves closed in time for the next compression stroke at those high rpms your lookin for. Also, with higher rpms comes the danger of your flywheel shattering. That’s what the light valve springs are for is to keep the rpms low enough to keep the flywheel from breaking and possibly hurting you. A billet aluminum flywheel can handle those high rpms and is also lighter just like the 3 hp flywheel y’all had. I don’t think it’s carburetor or fuel but I could be wrong. GREAT STUFF!
You can take the starter apart there are a few bearings inside. A lot of times they get gummed up and don't release. There's a hole and you can put a few drops of transmission fluid. There's a felt pad inside.
Hey guys, just passing on a tip from an old timer I got back in the 90's. If you keep shearing the flywheel key on a Briggs flatty, it's just from a sloppy fit. Put some valve grinding compound on the crank before sliding the flywheel on. It will take up the slop and you should be good to go. BTW, put some light oil in those starter clutches to keep them going. Also, the cutting out is probably fuel delivery.
Yeah, don't most of them have a pin hole in the top so you can put a few drops of oil in there when doing maintenance? Been quite a few years since I tore into a mower engine.
@@olds97lss yep. I remember trying a ton of different oils in mine and having some fantastic failures. I don't remember what worked best, I think it was marvel but it's been a long time.
300zxdriver, about nothing! ultrasonic cleaners can sometimes be found at a thrift store, or you can make one pretty easy with a very high RPM little DC motor and small weight (basic vibrator), firmly attached to the bottom of a metal coffee can a little offset from center. cleaning solution? for metal parts use kerosene and squeeze/mix half tube of cheap ultrabright toothpaste into it. give it rubber legs, or a handle to hang from a stand on a light spring (better). throw stuff in and let it run overnight. they're really THAT simple a device to make and use. "ultrasonic" just means the vibration is faster than 20khz, but it doesn't have to be, a 25-30,000 RPM motor can do the job too.
Hi from Wales,due to your influence, I have finally got a mower to mess with, 14 hp briggs Vee twin, got all the mowing tack off, and just about to switch pulleys about.....Although I am wondering if an "offroad" style might be more fun than a top speed mower (more fields to drive on around here) Might be a good build for you guys, a crawler mower......
Love the race guys! As for cutting out at the top end, fuel delivery for sure! (25+ yr mechanic) You can try - shortening the fuel line, raising the float level, or down sizing the main jet. One or a combination of those should solve your issue. Good luck, keep the videos coming!!
Dudes also sand the flywheel magnets for cleaner spark..look into light weight racing flywheels for quicker revving but less torque..starters munching themselves? Pry the cap off the starter where the bearings are or use the starter lube hole at the starter end of the crankshaft. Also more spring preload on pull start spring even 1 or 2 turns helps recoil alot!
One thing that really helps when a key keeps shearing is to hone the flywheel on the shaft with valve lapping grit because the cone holds it not the key. It can help and only takes a few minutes.
I suspected that there would be issues with the after-market parts, Briggs & Stratton engineers did a lot of work to tweak parts to make them durable and reliable. I love you Isaac, you know Briggs engines very well, I'm going to get your channel too, bud!
You guys need to do something bigger then all these small engine carts and bikes. May I suggest you get an old dirt bike 250cc, 2 or four stroke, don’t matter up to you, get a good chassis and go from there with shocks. Pump it out, I think I would be interesting and I think you guys might too.
one fix that we used was a larger fuel line, adapted to fit the carb. We also used a brake hone to hone out the air horn on the carb. Make sure that you do not have any pin hole leaks on the intake gasket, gasket sealer usually fixes that.
I had a MB in the '70s we used a 5HP BS from off of a old Tiller. Rebuilt the engine and oversized the bore. IT was pretty fast. the brake was a paddle that pushed on the rear tire.
Stater Clutch locked up .Polish crank where the spin mechanism resides ..If you tighten the Starter clutch a little tighter the key won;t be an issue .It is not compressing the compression washer tighten enough .Use a crescent wrench on the square shaft and tighten it as tight as you can and don;t beat on the Starter clutch . I was a small engine mechanic for 38 years and was diagnosed as a mechanical genius although I think they need a new test LOL
Hi, I see you change the value springs on the briggs, if you have good valve seats i took a long valve stem from a truck tube cut it off as long as you can knock the center of a spark plug out JB weld the valve stem into the plug. Put the plug in the head close both valves shoot air to the head it will hold enough pressure on the valves to remove the valve keepers release the air lift valve remove the springs. Works great if you don't want to pull the head.
Man I love youguys and your channel never give up on a Briggs they were first really like the paint scheme on the mini bike and engine it's fast and it's a vintage show bike 👍
love your videos and channel soo much, thank you guys for the awesomeness and blessful channel/videos, you guys are special to me and I'm thankful for you, God bless :), everyone have a good and blessed day!
Make sure you guys check gear ratios on both bikes. Also try to get tires size the same making them equal as possible. Great video as always. Really like the look of the blue mini bike. Has that old school look.
Those Briggs engines are awesome. Tough little motors. The flatheads were the best, but those units are getting pretty old now and thing break on them. Luckily parts are dirt cheap and they made millions of them.
I recently gotten 2 8hp 305cc flathead briggs and stratton engines and put on my coleman mini bike and actually going to build a performance 305cc with the other one
maybe add a pulse pump in line with the fuel line or bigger vent to the tank? i think rbg had a similar problem with one of the karts they built and ended up having to use a dirt bike vent with an extended tube and breather on the fuel tank, still, sweet build, cant wait to see how well that little blue minibike runs with the problems all sorted out
If the bowl is emptying faster than it's filling then hook up a lawn mower fuel pump. Most of them run of of a crankcase breather, so it should hook right up.I've tried the trick with a 3hp and it worked great.
Do a horizontal shaft Briggs opposed twin build!! Finicky engines but you guys would make an awesome series of videos with it I would love to see that!
Use valve grinding compound to lap the flywheel to the crankshaft. Use an offset key and raise the timing.Make sure you have a stock size jet in it for gasoline.
im surprised you guys don't have a spark plug cleaner. I have one that I got from an old motorcycle shop that was going out of business and they had an extra. I love it for junk projects so I don't have to waste needless cash buying new plugs for everything. ive reused plugs multiple times by just having a spare set that I cleaned and I swap plugs and clean the ones I just removed and put them back in after checking the gaps. I always clean and regap my plugs. I only ever buy new plugs when 1 goes bad.
sounds like 1 of two things from my experience. 1: It could possibly be the needle seating, if the needle is off you'll get to much or to little air at high RPM's causing a bog condition, or 2: I would like to say it's a seal problem on the intake but it'd be revving erratic from start to finish. I would check the bearing on your crankshaft... At high RPM's it's probably vibrating the flywheel to a shimmy and getting a little air in, which would totally disrupt pressures on the crank case. Just a thought, I can't wait to find out what it is! Watch it be a needle setting.
You need to lap the flywheel to the crank. Use valve grinding compound, keep at it until the flywheel and crank look like they mate perfectly. Then the flywheel will stay put and you won't sheer keys anymore. Also get that stater tighter than what you showed in the video. I think it sounds like it is either running out of gas in the float bowl (check float level) or the main jet is to small. It doesn't sound like valve float... Also check the gas tank vent.
Time to get the proper socket for the starter clutch. The clutch needs to be even tighter than "super dooper tight" Also lap the flywheel to the crank stub with valve lapping compound. It will increase the contact area and decrease the chance of it slipping prematurely Put a tiny little bit of oil on the shaft where it contacts the clutch bearings before you put the clutch back on. Problems will go away with it spitting out the rop.
for the cord coming out, squirt some oil in the little hole on the end of the starter, when its installed on the crank shaft. whats happening is the starter is sticking to the crankshaft and not freewheeling. no limiter it's probably the carb
I've been working on this stuff professionally for 36 years so I know a thing or two about these engines. You did not tightened the starter clutch well enough......this I observed before the engine was started. Secondly, it is a very common problem for the smooth part of the crankshaft to seize on the smooth bearing surface of the clutch. Sand the crankshaft smooth and make sure the felt plug has a drop of oil on it. The felt plug is inserted at the bottom the the long hole in the starter clutch. It's purposed is to lube and cushion the gap between the end of the crankshaft and the welch plug looking cap on the starter clutch. It did not seize and unscrew itself. There is a high pitched squeal when the crank and clutch seize. This partial seizure pushes the rope out. Left unattended it can even melt the spool for the rope if it is plastic. Hope this helps. Great work otherwise! PS. there is a special tool to remove the starter clutch so you can zip it of and on with a half inch impact.
Got what looks to be a speedway shrike. Building it for my grandson when he's old enough. But till then, for me. Any advice rebuilding the bike? Upgrade to disk brake if can... I can handle the 5hp Briggs on it. It's gonna get built by me. But don't know enough about restoring the frame fork is hard to turn so more bearings?
flattening a head low budget way : get the bathroom mirror and some 600 grit waterproof sandpaper put water on mirror flatten the sandpaper over the water so it sticks to the mirror put more water on the sanding paper lay the head on the sandpaper and start making figure 8 motions with light pressure , keep checking the shine on the mating surface if its fully filled in youre there , good way to raise the compression too after grinding a little of the mating surface using course sandpaper about the surging of the engine : could it be a floating or slightly stuck valve (then again it would pop and sputter if it was ) probably ignition , get some electronic ignition thing running of a battery to test that
You guys should lap the flywheel onto the crank. Wont need a key after that and you can advance the timing to take advantage of your "performance" camshaft.
You gotta use lapping compound on the hole in the flywheel and lap the flywheel to the crankshaft by turning the flywheel back and forth on the crankshaft and then clean the lapping compound off and then tighten the flywheel and you won't even need a flywheel key anymore.
Not sure if you guys know this but if you look at the starter, right in the middle of the square at the end you will see a hole. That’s how you lube the starter. Just pit the straw from a spray lube up against it and spray away. It has a felt like material inside that absorbs the lube and helps to keep it lubricated longer.
Cody Jv it comes with gaskets for carb and exhaust and a stright pipe header better jet for carb and the air filter adapter and air filter with filter sock and some gopowersports stickers but mine I got 18 pound valve spring there a add on
Oh also get a mirror or a piece of glass to flatten the head yourself. Put sand paper down on the glass and work your way up from 150 grit up to how ever high up you want to go.
You should try using N3 Diamond Fire spark plugs they are little more expensive but come with a 5 year warranty vs a 1 year warranty they seem to work very well with the small engine applications you can find them at O’Reilly auto part or online. They tend to go for around 6.99$ at O’Reillys but they are worth it.
heat the fly wheel up with a torch then install it while it is hot. the aluminum pull starts never hold the fly wheel down when the engine is built, I tried a few times, not enough torque.
Another great episode! I have a cousin who used to run 5hp briggs flatties in pro track cart racing, and he used to rebuild them after every race! He said that he experimented with 3hp flywheels and never noticed any difference whatsoever. I also saw that you're using the older style starter clutch and pull rope. I have that same pull rope setup on a vertical shaft lawnmower because they just don't wear out starter ropes! The new rope starters seem to need new rope about every 100 pulls. Did you add oil to the starter clutch before you put it on? I have seen them seize up in a hurry because of that. Just my 0.02
There is special tool that is used to torque the starter nut. It's common to break a flywheel key on these engines. The tool to torque it is made of cast iron, it will transmit torque to the 4 aluminium boss so you can use a torque wrench to torque the nut.
I restored my "CAT" minibike for my sons in the 90's. I bought a new Honda 5Hp OHV and a Comet "Torqaverter, new tires, had the seat recovered all the chrome polished, other worn parts replaced, repainted and new decals. Looked brand new, ran 10 times better than ever- it had take-off and top end. My ex got it, it from the boys and sold it. eos
I feel like your problems are coming from the flywheel/flywheel magnets. My hypothesis would be that the flywheel is vibrating at high rpm (warped or simply unbalanced), getting a few mm tolerance and shears the key, then loosens the starter nut. That would kind of make sense with that rev limit too.. the whole crankshaft could be shifting at high rpm and losing connection with the magnet/coil. I feel this is 100 percent a ignition issue, fuel seems more than ok to me.. plus its not running a fuel pump so less chances of it being a vacuum leak... being an internet mechanic is fun!
Couple of things that could be an issue: First the carb could be sucking in the exhaust causing vapor lock, second change the slid arm position on the carb as it might too rich for the engine, third (and one I think is the most likely cause) the fuel line has a weird bend in it after leaving the tank and with not enough vacuum from the motor it s causing the surging. The fuel issue could be solves either moving the engine forward some or adding in a pulse pump, this would get rid of the "S" bend in the line making the flow much more constant. If it is the exhaust being sucked into the carb just make the exhaust 3 inches longer. The second one is self explanatory. Also are you lapping the flywheels before installing the new keys? Seems odd that it is shredding keys like unless the surging is that strong.
you need to lap the flywheel to the crank with some valve lapping compound. after doing it the tapered part should show a gray area from the lapping material. if not you got a problem and it will keep on shearing the keyway off. I also thought I seen a adjustable coil bracket you use on the briggs or I should say came with it. left will advance it.
The key is just there for indexing, the tapered shaft interference fit is what keeps the flywheel in place. The shaft and flywheel need to be clean and the starter clutch should be torqued on better than I’ve seen in this video.
That's my one complaint about these guys. They leave hp on the table because they just drill out the jet and guess I'm sure ike has gotten good at it but they need a jet kit for their mikunis and stock carbs. And if I had the money I'd get a air fuel tester to tune
@@travis4798 nope unburned fuel. 1st of all Oil is blue when it burns coolant is white fuel is black... 2nd flat heads valves at upside down meaning the oil would have to go upwards past the valve seal and eek by the valve stem but this would also never happen because the breather is the "valve cover" so all the direction of flow is out the breather not up past the valves and into the the combustion chamber and it would have to be such a significant amount that it creates visible smoke.. sorry not buying it if u said the oil gets past the rings I might agree with ya Briggs are famous for burning oil and running for a good while and its usually due to the rings
And the Hip bone is connected to the Thigh bone . When I was young a 5 hp was the boss we had a big dirt field behind our school it had humps,bumps and a couple small jumps and when it rained that was a whole different experience just Fun Fun FUN !!! Try riding like that on school property now days their were six of us full time riders we cut lawns ,washed and waxed cars ,pulled weeds collect bottles and anything job we could to buy gas and parts ,I remember having to buy a few cables , no helmets or safety gear just sun glasses and a backwards ball cap those were the days .
Tank Soldier Awesome!! I’m jealous!
Bad Rad ,it was a blast ,wish l could do it all over again .
@@tanksoldier9770 We do the same thing around our farm
Joel Boley Hey there I see your Massey Harris sign I have an MH 22 great tractor right now it's not running it sat to long and it won't turnover and needs new tires ,and I have an old MH swather with wood spokes on the 10 ft header with drapers and lots of belts that was my first swather and l sold my pto MH bailer a while back it made nice 85 lbs bails ,I went to NH bailers 2 and 3 wire bailers 100lbs on the 2 wire and up to140 lbs on 4 th crop alfalfa with the 3 wire also I have a NH 2 twine and a JD 2 wire bailer , nothing beats a farm and ranch life !! Thanks TANK
@@tanksoldier9770 Massey Harris made good machinery back in the day.... We have a MH 444, three MH 30's two of which run and one that the engine is stuck, two MH 44's, and a MH 44 special. Good ol rake and baler tractors..... We do mostly hay and cattle farming. Wouldn't trade farm life!!!!
i think the coolest thing about UA-cam is that i have been able to watch you guys go from being one of the few vids on about minibikes and modding them to being a growing industry. And to see it be able to support your hobby, and friends you have made.. truly inspiring. From a guy you never met, on the other side of the U.S., keep up the good work.
Ike is so chill. I'd like to hang out with him. Would be good for my anxiety to be around someone so relaxed.
Ya
Ike is like that neighborhood dad that was so cool he made the other dad's look lame
Fuel delivery.
Bowl is emptying faster than it fills up.
That's my guess.
i agree 100%
Needs a fuel pump to fix that
I'd have to agree. The thing is suckin the bowl dry over and over again. They should put the old flywheel back on too. Seems like the heavier flywheel is being accelerated with enough force to sheer the keys constantly.
@@anythingthatmoves9609 Could also drill the bowl filler inlet out just slightly. I have done it with some success on chinese scoots.
@@izzyplusplusplus1004 where exactly do you drill? The outside of the carb where the gas enters, or the inside seat? Just curious haven't thought about trying it.
Love old flatheads ;) Your problem with the flywheel is easy. The key wont hold the flywheel, its just for easy timing. The crank is tapered and the wheel is fasten on the taper. The taper can have bad fit to the flywheel and then you need to take some valve grinding paste and grind the flywheel to the crank. You will see at the surface when you have grind enough. :)
The best thing with mondays and wednesdays is carsandcameras! :)
( Peter Hellberg
Peter Hellberg) is correct, you have lost the taper fit with the flywheel. It will never stay tight. Seen it plenty.
Correct Peter, this is what they need to do.
I have a b&s I believe a 1966 power craft 2HP that this gave me nice pointers Thank you 🙏🏼 please film more #Briggs&Statton videos!!!!!
I've worked professionally in my own small engine repair business for over 35 years and i can say without a doubt that the flywheel must be installed with an impact with the special tool or tighten it much more with the hammer than what I've witnessed you do. Also the starter clutch has been a problem on briggs engines. the trick is to polish the part of the crankshaft that inserts into the clutch, put a drop of oil on the fabric wick in the bottom of the hole on the clutch and clean the channels for the ball bearing in the housing. They can stick in the "sling out position". Also there is no rev limiter. The jetting may be too rich..........that's what it sounded like to me or possibly valve float.
I love these older frames, i got up to 40 with a 99cc i modified with stock gearing, thank you for everything youve done and for still making videos
The starter clutch/ratchet is a serviceable part. Use a bladed screwdriver and pop the black rubberized cap off, there will be 6 steel ball bearings inside put those aside and lift the ratchet out. use a piece of wire and push the felt dust cap out of the ratchet and clean the inside with degreaser and emery paper if needed and put the dust cap back in. give everything a good clean with degreaser and reassemble the clutch taking care to be clean. Before mounting it back on the crank use a piece of fine emery paper to clean up the crankshaft. It is debated in the industry whether you grease or leave the clutch dry, I personally run them dry as brand new OEM parts come dry.
I away put grease on mine.
Grease of any kind impairs it from working properly. Mabe a light oil.
If the ratchet assembly is dragging you may have a bur on the crankshaft end. Try polishing the shaft stem. Or if you hit it with a hammer it's mushrooomed....
I put a tiny little bit of oil on the shaft itself. Nothing in the ratcheting mechanism for reasons stated.
the concept inside the clutch is to let the balls move freely and the centrifugal force in running engine keep this balls away from the ratchets , putting oil will reduce this movement and with sum dirt that will be a good way to loose the clutch and the pully and in sum case the crankshaft.
John and ike, that starter clutch has to be super tight! You have to hold the flywheel with a strap or a bar on the find, then tighten the clutch ad tight as you can get it. As I have a small engine shop, I have the flywheel holder and wrench for the clutch, and a cup wrench I can use a impact to tighten the clutch. That cast iron flywheel has a lot of mass that the clutch had to retain. Also be sure to have the steel cup washer on there also.
Yup and the washer has to be the right way. I wouldnt use an impact itll snap the crank but the surfaces also have to be smooth and clean no burs or grease! Lap it with compound if you have to antiseize works in a pinch. Iv ran them without keys no problem its really just there to position it.
The following video features activities performed in controlled environments by knowledgeable persons. DO NOT attempt to duplicate, re-create, or perform the same or similar activities at home, as personal injury or property damage may result. CARS AND CAMERAS, the persons shown in this video and ANY CONTRIBUTOR, ARE NOT LIABLE FOR ANY such injury or damage. ALL CARSANDCAMERAS CONTENT IS FOR ENTERTAINMENT PURPOSES ONLY.
You guys never give up. Never quit. If you don't know you figure it out. Not many of us left. It's all computer now. Keep on keepin on.
I hope y'all dnt ever run out of stuff to do cuz y'all make my Mondays so much better n I wanna say thank you iv learned so much from you guys and have had a lot of my own fun because of you thank u again
You guys are making me want to get another old Briggs and Stratton Mini bike. I had a bunch of old go carts from the 70s and sold them but Im going to find one of these and buy it.
This video was awesome to watch! It just goes to show how easy C&C can overcome so many obstacles. I like learning from you guys! It might have taken all day but you guys have a sweet running mini bike now!
That thing dose grate burnouts!!
The great words of Ike "Something happened, Something happened" lol keep up the great work guys
If you're shearing keys left and right, that means the flywheel's and crank's tapers are not mating and locking together properly. You need to get some valve lapping compound and lap the 2 together. The key doesnt do anything to hold the flywheel in place, it is ONLY for alignment for timing. You need good mating tapers. And, get yourselves a piston stop that screws into the spark plug hole so you can torque that nut properly.
brandon2076 yep key just sets the timing. Tapers hold it all together from spinning
Finally someone who knows what theyre talking about.
@@jeep2003 it's a common misconception in the world of small motors! Lol
Sounds very much like valve float...if you buy aftermarket heavier springs specifically designed for the Briggs it should stop that. I think the predator springs were either too short or not strong enough to get those valves closed in time for the next compression stroke at those high rpms your lookin for. Also, with higher rpms comes the danger of your flywheel shattering. That’s what the light valve springs are for is to keep the rpms low enough to keep the flywheel from breaking and possibly hurting you. A billet aluminum flywheel can handle those high rpms and is also lighter just like the 3 hp flywheel y’all had. I don’t think it’s carburetor or fuel but I could be wrong. GREAT STUFF!
I hope you guys stay after it because I really enjoy your projects.
You can take the starter apart there are a few bearings inside. A lot of times they get gummed up and don't release. There's a hole and you can put a few drops of transmission fluid. There's a felt pad inside.
Hey guys, just passing on a tip from an old timer I got back in the 90's. If you keep shearing the flywheel key on a Briggs flatty, it's just from a sloppy fit. Put some valve grinding compound on the crank before sliding the flywheel on. It will take up the slop and you should be good to go. BTW, put some light oil in those starter clutches to keep them going. Also, the cutting out is probably fuel delivery.
Yeah, don't most of them have a pin hole in the top so you can put a few drops of oil in there when doing maintenance? Been quite a few years since I tore into a mower engine.
@@olds97lss yep. I remember trying a ton of different oils in mine and having some fantastic failures. I don't remember what worked best, I think it was marvel but it's been a long time.
dissasemble the carbeurator and stick it in a untrasonic cleaner... it works wonders dude
Desaint Mustie1 Would be proud of you
Desaint How much does it cost.
300zxdriver, about nothing! ultrasonic cleaners can sometimes be found at a thrift store, or you can make one pretty easy with a very high RPM little DC motor and small weight (basic vibrator), firmly attached to the bottom of a metal coffee can a little offset from center.
cleaning solution? for metal parts use kerosene and squeeze/mix half tube of cheap ultrabright toothpaste into it. give it rubber legs, or a handle to hang from a stand on a light spring (better). throw stuff in and let it run overnight. they're really THAT simple a device to make and use.
"ultrasonic" just means the vibration is faster than 20khz, but it doesn't have to be, a 25-30,000 RPM motor can do the job too.
@@300zxdriver harbor freight sells them for about $80
That back fire at 12:28 was unreal
Hi from Wales,due to your influence, I have finally got a mower to mess with, 14 hp briggs Vee twin, got all the mowing tack off, and just about to switch pulleys about.....Although I am wondering if an "offroad" style might be more fun than a top speed mower (more fields to drive on around here) Might be a good build for you guys, a crawler mower......
I've had that happen a few times cause of starter issues and you are totally correct doesn't damage anything but the key itself
Love the race guys! As for cutting out at the top end, fuel delivery for sure! (25+ yr mechanic) You can try - shortening the fuel line, raising the float level, or down sizing the main jet. One or a combination of those should solve your issue. Good luck, keep the videos coming!!
I love the vintage mini bike pls more vids on the mini bike
Dudes also sand the flywheel magnets for cleaner spark..look into light weight racing flywheels for quicker revving but less torque..starters munching themselves? Pry the cap off the starter where the bearings are or use the starter lube hole at the starter end of the crankshaft. Also more spring preload on pull start spring even 1 or 2 turns helps recoil alot!
Sometimes I feel like I’m there with you guys.
Great videographer
One thing that really helps when a key keeps shearing is to hone the flywheel on the shaft with valve lapping grit because the cone holds it not the key. It can help and only takes a few minutes.
I suspected that there would be issues with the after-market parts, Briggs & Stratton engineers did a lot of work to tweak parts to make them durable and reliable. I love you Isaac, you know Briggs engines very well, I'm going to get your channel too, bud!
You guys need to do something bigger then all these small engine carts and bikes. May I suggest you get an old dirt bike 250cc, 2 or four stroke, don’t matter up to you, get a good chassis and go from there with shocks. Pump it out, I think I would be interesting and I think you guys might too.
one fix that we used was a larger fuel line, adapted to fit the carb. We also used a brake hone to hone out the air horn on the carb. Make sure that you do not have any pin hole leaks on the intake gasket, gasket sealer usually fixes that.
I had a MB in the '70s we used a 5HP BS from off of a old Tiller. Rebuilt the engine and oversized the bore. IT was pretty fast. the brake was a paddle that pushed on the rear tire.
Stater Clutch locked up .Polish crank where the spin mechanism resides ..If you tighten the Starter clutch a little tighter the key won;t be an issue .It is not compressing the compression washer tighten enough .Use a crescent wrench on the square shaft and tighten it as tight as you can and don;t beat on the Starter clutch . I was a small engine mechanic for 38 years and was diagnosed as a mechanical genius although I think they need a new test LOL
I love watching your videos guys the engines and toys caught my attention but your friendship mixed in with all made me stay you guys are awesome
As we say down here in Texas.... " If it wasn't for bad luck... you wouldn't have any luck"! Great Vid Guys Keep me entertained I am Love'n it Rusty
Hi, I see you change the value springs on the briggs, if you have good valve seats i took a long valve stem from a truck tube cut it off as long as you can knock the center of a spark plug out JB weld the valve stem into the plug. Put the plug in the head close both valves shoot air to the head it will hold enough pressure on the valves to remove the valve keepers release the air lift valve remove the springs. Works great if you don't want to pull the head.
Man I love youguys and your channel never give up on a Briggs they were first really like the paint scheme on the mini bike and engine it's fast and it's a vintage show bike 👍
Nice mini bikes. I'd like to see you make a little dirt bike track and race around it, put some numbers on the bikes.
Thank you for all of your hard work. Great content, consistent upload schedule, plentiful information, and 2 awesome dudes. You guys rock.
love your videos and channel soo much, thank you guys for the awesomeness and blessful channel/videos, you guys are special to me and I'm thankful for you, God bless :), everyone have a good and blessed day!
You guys are mini bike/go-kart geniuses
Make sure you guys check gear ratios on both bikes. Also try to get tires size the same making them equal as possible.
Great video as always.
Really like the look of the blue mini bike.
Has that old school look.
Those Briggs engines are awesome. Tough little motors. The flatheads were the best, but those units are getting pretty old now and thing break on them. Luckily parts are dirt cheap and they made millions of them.
I recently gotten 2 8hp 305cc flathead briggs and stratton engines and put on my coleman mini bike and actually going to build a performance 305cc with the other one
Very cool guys, can’t wait for the next one
Your guys persistence always amazes me!. Great episode
maybe add a pulse pump in line with the fuel line or bigger vent to the tank? i think rbg had a similar problem with one of the karts they built and ended up having to use a dirt bike vent with an extended tube and breather on the fuel tank, still, sweet build, cant wait to see how well that little blue minibike runs with the problems all sorted out
Lap the flywheel onto the crank shaft with valve grinding compound and clean it well, you may not have any more issues with the flywheel coming loose.
kool scooters, burn outs and a close race. Good stuff, keep it up.
Really nice bike! I love the blue!
If the bowl is emptying faster than it's filling then hook up a lawn mower fuel pump. Most of them run of of a crankcase breather, so it should hook right up.I've tried the trick with a 3hp and it worked great.
Do a horizontal shaft Briggs opposed twin build!! Finicky engines but you guys would make an awesome series of videos with it I would love to see that!
I had a mini bike same as the blue one same blue almost and it was fast lol. My uncle found it in the trash and gave it to me . Wow what memories
Use valve grinding compound to lap the flywheel to the crankshaft. Use an offset key and raise the timing.Make sure you have a stock size jet in it for gasoline.
im surprised you guys don't have a spark plug cleaner. I have one that I got from an old motorcycle shop that was going out of business and they had an extra. I love it for junk projects so I don't have to waste needless cash buying new plugs for everything. ive reused plugs multiple times by just having a spare set that I cleaned and I swap plugs and clean the ones I just removed and put them back in after checking the gaps. I always clean and regap my plugs. I only ever buy new plugs when 1 goes bad.
U should do a goped build. They are sweet and more practical for teens with a tight budget.
Hey check out our channel, we have a build video and riding of my goped sport that I built and we'd appreciate the support!
Who cares about practical? They're boring af... I don't think the channel is based on, "getting to the campus library in a pinch, and on a budget"...
sounds like 1 of two things from my experience. 1: It could possibly be the needle seating, if the needle is off you'll get to much or to little air at high RPM's causing a bog condition, or 2: I would like to say it's a seal problem on the intake but it'd be revving erratic from start to finish. I would check the bearing on your crankshaft... At high RPM's it's probably vibrating the flywheel to a shimmy and getting a little air in, which would totally disrupt pressures on the crank case. Just a thought, I can't wait to find out what it is! Watch it be a needle setting.
You need to lap the flywheel to the crank. Use valve grinding compound, keep at it until the flywheel and crank look like they mate perfectly. Then the flywheel will stay put and you won't sheer keys anymore. Also get that stater tighter than what you showed in the video. I think it sounds like it is either running out of gas in the float bowl (check float level) or the main jet is to small. It doesn't sound like valve float... Also check the gas tank vent.
Time to get the proper socket for the starter clutch. The clutch needs to be even tighter than "super dooper tight"
Also lap the flywheel to the crank stub with valve lapping compound. It will increase the contact area and decrease the chance of it slipping prematurely
Put a tiny little bit of oil on the shaft where it contacts the clutch bearings before you put the clutch back on. Problems will go away with it spitting out the rop.
670 v-twin + rat rod wagon = BIG Fun. Nuff said.
merci les gars pour les vidéos like yours style les bro from TAHITI french polynésia
for the cord coming out, squirt some oil in the little hole on the end of the starter, when its installed on the crank shaft. whats happening is the starter is sticking to the crankshaft and not freewheeling. no limiter it's probably the carb
I've been working on this stuff professionally for 36 years so I know a thing or two about these engines. You did not tightened the starter clutch well enough......this I observed before the engine was started. Secondly, it is a very common problem for the smooth part of the crankshaft to seize on the smooth bearing surface of the clutch. Sand the crankshaft smooth and make sure the felt plug has a drop of oil on it. The felt plug is inserted at the bottom the the long hole in the starter clutch. It's purposed is to lube and cushion the gap between the end of the crankshaft and the welch plug looking cap on the starter clutch. It did not seize and unscrew itself. There is a high pitched squeal when the crank and clutch seize. This partial seizure pushes the rope out. Left unattended it can even melt the spool for the rope if it is plastic. Hope this helps. Great work otherwise! PS. there is a special tool to remove the starter clutch so you can zip it of and on with a half inch impact.
U guys are the best at this stuff
Got what looks to be a speedway shrike. Building it for my grandson when he's old enough. But till then, for me. Any advice rebuilding the bike? Upgrade to disk brake if can... I can handle the 5hp Briggs on it. It's gonna get built by me. But don't know enough about restoring the frame fork is hard to turn so more bearings?
hey guys love the channel and have been subscribed for years. wouldnt change a thing guys except maybe equalize the volume please
Mate the flywheel to the crankshaft with some lapping compound. No matter how much you torque it, it's not solidly mounted until it's mated.
Awesome video again!
I love old school briggs , keep up the old style briggs .
flattening a head low budget way : get the bathroom mirror and some 600 grit waterproof sandpaper
put water on mirror flatten the sandpaper over the water so it sticks to the mirror put more water on the sanding paper lay the head on the sandpaper and start making figure 8 motions with light pressure , keep checking the shine on the mating surface if its fully filled in youre there , good way to raise the compression too after grinding a little of the mating surface using course sandpaper
about the surging of the engine : could it be a floating or slightly stuck valve (then again it would pop and sputter if it was )
probably ignition , get some electronic ignition thing running of a battery to test that
You do have the coolest driveway and yard/race course.
Awesome episode, but you should turn the Indy kart into a performance/handling/race kart. Slick tires would look so cool.
On the old Briggs the pull start has a felt pad inside just put a few drops of oil on it and also a lil on the bearings inside the pull start assembly
You guys should lap the flywheel onto the crank. Wont need a key after that and you can advance the timing to take advantage of your "performance" camshaft.
You gotta use lapping compound on the hole in the flywheel and lap the flywheel to the crankshaft by turning the flywheel back and forth on the crankshaft and then clean the lapping compound off and then tighten the flywheel and you won't even need a flywheel key anymore.
Not sure if you guys know this but if you look at the starter, right in the middle of the square at the end you will see a hole. That’s how you lube the starter. Just pit the straw from a spray lube up against it and spray away. It has a felt like material inside that absorbs the lube and helps to keep it lubricated longer.
My friend got me a tshirt for Christmas from you guys. Also it sounds like my atv was the bowl couldn't fill quick enough
Got a profomance kit for my ct200u it is sooo much better glad I found you all and go powersports keep it up guys love it
What all did it include ? Slow from purchase it's slow
Cody Jv it comes with gaskets for carb and exhaust and a stright pipe header better jet for carb and the air filter adapter and air filter with filter sock and some gopowersports stickers but mine I got 18 pound valve spring there a add on
Oh also get a mirror or a piece of glass to flatten the head yourself. Put sand paper down on the glass and work your way up from 150 grit up to how ever high up you want to go.
Looking forward to the race
You should try using N3 Diamond Fire spark plugs they are little more expensive but come with a 5 year warranty vs a 1 year warranty they seem to work very well with the small engine applications you can find them at O’Reilly auto part or online. They tend to go for around 6.99$ at O’Reillys but they are worth it.
Valve grinding compound on the crankshaft will hold the flywheel in place.
Dude you gotta RESPECT the Briggs buddy.. LOL 🤘
heat the fly wheel up with a torch then install it while it is hot. the aluminum pull starts never hold the fly wheel down when the engine is built, I tried a few times, not enough torque.
Another great episode! I have a cousin who used to run 5hp briggs flatties in pro track cart racing, and he used to rebuild them after every race! He said that he experimented with 3hp flywheels and never noticed any difference whatsoever. I also saw that you're using the older style starter clutch and pull rope. I have that same pull rope setup on a vertical shaft lawnmower because they just don't wear out starter ropes! The new rope starters seem to need new rope about every 100 pulls. Did you add oil to the starter clutch before you put it on? I have seen them seize up in a hurry because of that. Just my 0.02
We did add oil
I got a reply from Issac! This is as close to meeting a superstar as I'll probably ever get,lol! Big fan of the show,guys!
There is special tool that is used to torque the starter nut. It's common to break a flywheel key on these engines. The tool to torque it is made of cast iron, it will transmit torque to the 4 aluminium boss so you can use a torque wrench to torque the nut.
I restored my "CAT" minibike for my sons in the 90's. I bought a new Honda 5Hp OHV and a Comet "Torqaverter, new tires, had the seat recovered all the chrome polished, other worn parts replaced, repainted and new decals.
Looked brand new, ran 10 times better than ever- it had take-off and top end.
My ex got it, it from the boys and sold it. eos
beotch
Bring back the turbo drift trike please do a revival on it please it was such a great build
I love when there is a notification of this guys :D
My racing mower did the same thing so I added a file pump and bypass and it fixed the issues
Another great video. Keep up the good work!
See what happens when Murphy comes to visit. A sacrifice to the small engine gods is in order.
You guys should get an O2 sensor for diagnosing and carb tuning.
I feel like your problems are coming from the flywheel/flywheel magnets. My hypothesis would be that the flywheel is vibrating at high rpm (warped or simply unbalanced), getting a few mm tolerance and shears the key, then loosens the starter nut. That would kind of make sense with that rev limit too.. the whole crankshaft could be shifting at high rpm and losing connection with the magnet/coil. I feel this is 100 percent a ignition issue, fuel seems more than ok to me.. plus its not running a fuel pump so less chances of it being a vacuum leak... being an internet mechanic is fun!
Couple of things that could be an issue: First the carb could be sucking in the exhaust causing vapor lock, second change the slid arm position on the carb as it might too rich for the engine, third (and one I think is the most likely cause) the fuel line has a weird bend in it after leaving the tank and with not enough vacuum from the motor it s causing the surging. The fuel issue could be solves either moving the engine forward some or adding in a pulse pump, this would get rid of the "S" bend in the line making the flow much more constant. If it is the exhaust being sucked into the carb just make the exhaust 3 inches longer. The second one is self explanatory. Also are you lapping the flywheels before installing the new keys? Seems odd that it is shredding keys like unless the surging is that strong.
you need to lap the flywheel to the crank with some valve lapping compound. after doing it the tapered part should show a gray area from the lapping material. if not you got a problem and it will keep on shearing the keyway off. I also thought I seen a adjustable coil bracket you use on the briggs or I should say came with it. left will advance it.
The key is just there for indexing, the tapered shaft interference fit is what keeps the flywheel in place. The shaft and flywheel need to be clean and the starter clutch should be torqued on better than I’ve seen in this video.
yes,the tapered shaft is what locks the two together and the keyway is just for timing.
Sweet bike. Looks a lil rich lol (black smoke)
That's my one complaint about these guys. They leave hp on the table because they just drill out the jet and guess I'm sure ike has gotten good at it but they need a jet kit for their mikunis and stock carbs. And if I had the money I'd get a air fuel tester to tune
@@travis4798 nope unburned fuel. 1st of all Oil is blue when it burns coolant is white fuel is black... 2nd flat heads valves at upside down meaning the oil would have to go upwards past the valve seal and eek by the valve stem but this would also never happen because the breather is the "valve cover" so all the direction of flow is out the breather not up past the valves and into the the combustion chamber and it would have to be such a significant amount that it creates visible smoke.. sorry not buying it if u said the oil gets past the rings I might agree with ya Briggs are famous for burning oil and running for a good while and its usually due to the rings
Black smoke usually mean oilbut it migt be blue i dont remember?
More Briggs!!!
bingo, jetted TOO large can be draining the bowl really quickly too.
I so love how you guys go at each other @ 13:36. Haha