Engine Puttering?

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psprat496

New Member
Nov 22, 2009
159
0
0
New Jersey
This is weird. I finally put another bike together with the new style NT carb. The engine is a Skyfire 66cc with about 50+ miles on it. The bike runs pretty well but for some reason when I rev the engine it will start puttering. It revs up but then it takes at least 2 seconds for it to rev back down to its normal idle.

Any ideas what could be causing this?
 

psprat496

New Member
Nov 22, 2009
159
0
0
New Jersey
Probably four cycling, possibly air leaks. Squirt some carb cleaner around the intake, at the carb and at the cylinder, with the engine running. If the RPMs change, you have an air leak.

Might be worth dropping the float bowl and making sure the jet and emulsion tube are in tight. Otherwise, run it for a while and don't worry about it until you've got a few tanks through it.
Would an air leak damage the engine if ignored? And if I do find the leak what should I do to repair it?
 

Maxvision

New Member
Jun 13, 2009
551
1
0
San Diego, CA
I had the same problem when I drilled my carburator jet too big. Even though I let go of the throttle gas would still suck past the needle. Did you try dropping the needle a notch or two?