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49cc 4 stroke bike engine upgrades

So this is my 49 cc kiwa shang bike engine it’s for my scooter painted this i gave this a paint job it kind of reminds me of iron man i dub it iron carb but anyways i’m gonna go over what i’ve done to it the best way to get power out of one of these is to let it breathe flow it’s kind of like a flathead you gotta let it breathe since there’s no cylinder head

To remove on this engine you have to do exhaust and carb work in order to make any sort of power out of this normally i would pull a head off an engine do some port work smooth it out bore it out a little bit help things flow but this is these two pieces right here you can barely faintly see it this right here this and this are exhaust pieces from a two-stroke

Bike kit i just cut them off this is a rubber hose from home depot and this is a 139 qmb carburetor racing carburetor for a 49 cc gy6 uh scooter motor usually found on tau taus or some yurf dog go-karts this is a three-quarter inch pipe threaded pipe threaded coupler and this is a nine dollar nine or ten dollar um eight or nine horsepower bricks and stratton

Sausage muffler just threads in here so when you want to be quiet you have this on here and when you want to annoy the neighbors and wrap down the road you just do that or you want to make little blown bubble sounds when it idles you go it’ll just go but this right here this configuration gave this little engine enough power to s to slip the stock stock clutch

I can’t use the stock clutch it just slips it no matter what and i’ve tried multiple clutches and they all do the same thing so i got the upgraded clutch to like 15 bucks on ebay or you can find them on i don’t think bikeberry has them but i got mine from ebay i’ve had really good luck with it it’s not just three little chunks of clutch material

It’s all the way around my crank case vent is just a fuel filter gotta get one of these filters for this car because this flows really well and filters the filter that comes with this carburetor is crap you can look right through the damn thing i’m running a number 80 jet number 80 main jet and i think it’s the number 30 idle jet um it would it won’t run

Unless you plug this right here i’ll turn the flash on real quick you gotta fill this hole with epoxy that’s what’s called the enricher jet there would be a black piece right here that would connect to the battery and it would it would have this copper coil in it that would warm up and as it produced heat it would open well it would close the jet basically this

Don’t have a choke so it would enrich it give it more gas so you plug that and this thing will start one pull every time i’ve got i’ve got to drain that out because that gas is just cheap irving gas and it went stale after a month it’s all orange and smells so i’m not running that through it i’m gonna get some shelvey power that likes that yeah this is what

You gotta do right here plus it looks nice like that looks really good i plan on painting the whole block with um it’s over here this stuff right here um that’s what this is what i used to paint the carb i have a few spots to touch up on the carb uh it was a pain in the rear to tape it i wanted to keep all the screws and bracketry looking the same so i did my

Best to tape everything i missed a few spots here and there i’m not the greatest painter but i think it looks alright it sounds great um it was down for the count because it blew a tire out i gotta get rid of this friction drive system i’ve had three tire blowouts and the last one the tire just bang like a gunshot and my buddy almost he thought he was gonna run

Me over because i started going and this tops out at 36 miles an hour easy it goes faster than his tau town moped i leave him in the dust i have plans to make this a shifter i’m gonna get rid of this assembly right here i’m gonna um make an adapter to put a sprocket on here to hell with the centrifugal clutch and i’m gonna put a four speed gearbox right here

And just run a chain to this rear rim and probably modify this brake drum to take a sprocket i was going to use a derailleur system but it’s too small of a tire and when you open it up when you go to shift into first it hits the ground so i don’t have the right size tires for that but this is what you got to do right here looks good sounds good runs amazing

139 qmb racing carburetor found on amazon or ebay for around 25 bucks number 80 jet number 30 idle jet and about 15 dollars worth of parts from a tractor supply and just a little bit of welding came out good

Transcribed from video
49cc 4 stroke bike engine upgrades By Mr Partridge