No power at 35 mph. On my buddy 125

[nuckingfuttz78]

Do I have a 2007 genuine Buddy 125CC. I'm having problems with power at 35 miles per hour. It'll start up and run as soon as I get to about 30 or 35 miles per hour it starts to sputter and backfire and it has no power after that I've put a aftermarket exhaust . Also have pod air filter. I have 30 mm cvk carburetor and big valves on a 161 CC piston cylinder. could be my Jets are not right. Any suggestions with this would be great

[Zino]

what was the last parts you changed before you had low power?

Th carb diaphagm sometimes doesnt seal right .