rev it up on the go and slowly revs come down why

[skyash]

when i start my bike it will not idle till it warms up then it will fine when i get up to eny speed it keep hi revs then they come down slowly back to idle ..need help ...

 

[butre]

if it takes a while to idle down that probably means you have a vacuum leak somewhere. if not around the carb then somewhere else

 

[skyash]

so if i spry wd.40 or water on motor may be find leak ?

 

[crassius]

yes, just spray around the intake pipe

 

[skyash]

all good did that and it made a funny noise where the carby gos on the intake pipe its a new one steel not that stock rubbish ..thanks...

 

[crassius]

those steel intakes often have a bit of a lip on the end where the chrome was put on - I sometimes need to file it a bit right there to get a good fit for the carb

 

[Waxxumus]

all good did that and it made a funny noise where the carby gos on the intake pipe its a new one steel not that stock rubbish ..thanks...

This is why you spray with a little carb cleaner.
The rpm will rise if its an air leak.

 

[Waxxumus]

or just get rid of that stock nt carb. its a 50 cc carb on a 66 cc engine.

 

[crassius]

the old speed carb was a millimeter or 2 smaller & was the 50cc version