Help please with 85 tri zinger

[dovesprings250R]

Hey guys, just put a bassani exhaust system on my 85 yamaha tri zinger 60....air cooled two stroke. It was running pretty strong with the stock system. Now with the new one it won't really pull at all anywhere in the rmp range. So far I've cleaned the carb and air filter/air box. Want do you think? Does it need more air or more fuel? The new system is much better flowing it appears. I don't have any spare jets for this one so hopefully I can get it going with what I've got. Since I've cleaned everything I haven't tried it yet. Anybody have any experience with these. Any help is appreciated.

[Unclediezel]

Unfortunately---The only way to fix your problem is either put the old exhaust back----OR Rejet---

[kpmengr]

I agree. You need to rejet the carb with a larger main and maybe pilot. The PW50 uses the same carb.