Motorcycle Repair: suzuki gn125 trottle, stock air filter, gn 125

Question
My 1995 gn 125 has about 3,500 mi.  The carb is real clean.  I'm having trouble with the bike running at too high rpm.   If I rev it the rpms come down but then climb back up.  Any ideas?

Answer
Hi Paul.

It could be jetting.
Is the bike stock? Any mods to the intake, air filter or exhaust?
Are the jets stock? Air filter clean?

Make sure everything is in order and try running a half bottle of SeaFoam engine treatment through the tank and see if it improves.