air puffing from carb

[byh0005]

im restoring an old bike and im getting air puff out the air filter side of the carb when i try to kick it over its my first two stroke and im not sure if this is normal iv cleaned the carb jets are clean its all clean in there help would be nice

 

[sean01]

check the reeds... pretty comon for them to sht themself.

other than that make sure its not getting to much fuel. turn the fuel off and drain the carb and keep kicking for a bit and see if it changes

 

[byh0005]

i am told this bike hasn't got reeds i don't know much about 2 stroke engines but it has a rotary vale(instead?) so i dont think its the reeds
its a 1973 kwasaki mc1 if that helps

 

[Cactus Jack]

I was just going to say they had a rotary valve on the end of the crank ...

It sounds like the disc or the crank bearings or seals could be worn ... or maybe the disc isn't timed right ? ... Can you wobble the end of the crank or move it sideways ? ... Maybe the ignition timing is out of whack ... ie flywheel key sheared or missing ......

I was going to get my gran to me buy one of those as my first bike back when they were new ... but I ended up getting an XR75 instead ...

Most of the early model mini bikes had 2 stroke horizontal rotary valve motors with oil injection ... but they had el crappo trannies too ... they'd miss a gear , rev , then bog when they crunched into the next higher gear ... I remember being extremely glad I'd bought a super reliable 4 stroke ...

 

[byh0005]

cant reach the crank mainly because the engine is still in 1 piece my auto teacher told me it may be the crankcase seals that are gone so ill check everything listed last resort ill save up some money and get a professional to get it going