Sup.
I have a problem with my friend's banshee.
He recently purchased a dynoport 2into 1 pipe plus added new 28mm PWK kehein carbs, plus vforce reed valves and pro-design intake manifolds.
The quad was jetted to 168 mains and I did a plug check and it was running lean.
So we jumped to 185 mains and it now responds the same at half throttle, but when you go more than half throttle the quad looses power and start to sputter like crazy.
The spark plug looks tan, any ideas.
Thanx

 

First of all, Dynoport should be able to get you started in the right direction as far as jetting is concerned. If any pipe manufacturer DOESN'T help, then you went with a pizz poor manufacturer. If you want to do the jet testing yourself then I will give you some advice. It sounds like the current mains are too big. The sputtering is caused by too much fuel. Your best bet is to come down a little at a time until wide open starts to run well. You may need to raise the needle to keep the lower throttle setting above lean.