throttle/choke problems

[bobo333]

hi guys, i just bought a chinese 50cc two stroke engine for my mountain bike ( i plan to make a chopper frame in the future) and im am in the process of running it in, my problem is that i constantly need to adjust the choke depending on how much throttle, speed and load i have on the bike, is this just because its still running in or is my carby stuffed? its still rideable but its kind of annoying having to adjust the choke every 5 seconds.

 

[azbill]

we need a little more info to give advice
choke should only be needed when starting (I never need it, but am located in desert)
have you checked for air leaks on both side of intake?

 

[bobo333]

i dont think there are any leaks on either side of intake, when im starting it i need the choke all the way on. once its warmed up i move the choke off about a quarter for it to run properly, then when i get going up hills etc at full throttle i need the choke about halfway on. when i go downhills with speed or into the wind i need to put on the choke almost full again otherwise it leans out and stalls. it that enough info (tell me what else you need)

 

[gone_fishin]

those sypmtoms indicate an air leak (ok, maybe mixture adjustment, but i'm leaning towards air leak)...doesn't matter if that's what you want it to be or not...you don't think it is, or you re-checked?

gaskets and flanges, carby connection, cylinder gasket, head, spark plug...something's creating a lean run...

try an "introduce yourself" and maybe make some friends who'll jump in and try to help.

 

[bobo333]

thanks guys, i checked for leaks again last night and i think where the carby joins onto the intake (it slips over and uses a hose clamp type thing to stop it coming off) it could be leaking here but i cant really tell, how could i fix this if it is?

 

[Herrmanator8]

if i understand what your talking about, i had the same problem. where the carb clamp hole meets the intake maniford. there was a gas and air leak on mine. i fixed it by cutting out the exact size gasket out of gasket paper. it hasnt leaked since. put a piece of gasket paper on the mainifold beginning, draw a circle and start cutting, i used an exacto knife to get the precision cut needed.

jon

 

[bobo333]

thanks, i try that tonight.

 

[Herrmanator8]

no problem. ive had no carb problems since. if you have a leak where the gas hose line meets the carburetor, use a metal hose clamp,turn the screw till you cant anymore, but be careful, the brass piece is delicate. just in case you run into that problem.

jon

 

[bobo333]

hey thanks for the tip, i had a small fuel leak when i first got it but that just turned out to be the float bowl screws werent done up tight enough, i tried the gasket idea, works fine now! thanks.