Kymco super 9 61 plate

[Lukkey11]

Hi I'm new to this site I have a kymco super 9 61 plate recently I've upgraded the barrel and piston to a 70cc it's got a airsal 70cc kit with a naraku 17.5m carb with polini variator and rollers think there 8 gram technigas race pipe mosilia reeds need help as it's firing up after a while but back firing get up to full revs it back fires then won't rev till I've slowed down

[2wheelfun]

This is just a guess from your post that I'm able to decipher, sounds like a timing issue to me.

[Lukkey11]

Thanks for the reply I've done timing it's perfect

[zombie]

I just answered a PM.
It sounds lean if anything.
Start by posting what size jets are in the carb, and let's go from there.
It could also be an air leak in the cases, or intake tract.

Are you running an air box or a "pod" type filter?