more scooter problems

speedfight 2 50cc has had full engine rebuild due to high mileage,it will start and run but as soon as I give it throttle it doesn't respond at all just sort of bogs and farts about, new parts are as follows;

stator plate :good:
piston and rings :good:
cdi :good:
coil :good:
main bearings and oil seals :good:
spark plug :good:
boyeseen reed valve :good:
regulator :good:
2nd hand carb as i broke the oil feed on the other 1 :banghead:

put the engine back to together and got the bike started now it doesn't respond to revs tried a different carb and different reeds,any help would be appreciated as I'm running out of ideas and bikes been off-road ever since it broke down due to compression loss .



thanks in advance Jordan

 

thanks for reply,did all that still no joy,tryed every jet right up2 a 72

 

i had same problem with my old scooter, it turns out that the inlet manifold was sucking in air somewhere, id try that, while its running pour some water on the inlet and see if theres any bubbles. If there is you either havent sealed your inlet right or its got a hole/crack/rip in it

 

thanks for commenting mate,its got a alloy one on it im thinking its standard ? but not too sure will try that tomo

 

Dont pour water onto the manifold... Use WD-40, because if water enters the engine it will destroy it.

If the engine has been rebuilt & still wont run then its probably not been built properly. Strip it down & start again

 

shit i meant wd40 lol and it just soumds like a carb/exhaust/inlet problem, to me theres too much air getting into the engine, i had 2 bikes that did it

 

exhaust problem ? would it be possible for air to travel UP an OUTLET ( exhaust ) or am i missing the point, lol

 

the exhaust should be sealed tight to the head with a gasket, but its ok if it blows, the gas coming out will not let much air in lol

 

yeah yeah thats whatta thought,just wanted to check,never been so frustrated over a scooter which i cant find the problem to :/

 

hi just read your post have u put the piston in upside down sounds like it the arrow should face towards exhaust port

 

yer mate change the piston round i did this once it will fuck it up and also check the seals and also check the needle is in the right postition its different for different carbs check the haynes

 

also check the mixture screw. i had a scoot once that wouldnt run without a filter when i messed with the screw i found the perfect setting. can you not fit your old carb and run premix to see if that fixes it if you know it ran fine before