ATC 110 Jetting Question

[KI4UJO]

My 85 110 has an 83 110 motor with the stock carb, recently rebuilt. It also has no airbox, and a 125m exhaust. To be honest, the power lacks from when this same motor was in a 110 frame with the 110 exhaust (Technically it's a 85 110, it's really an 85 125m frame with an 83 110 motor). Now, it just doesn't have the same speed and top end power that it used to. As far as I know, reinstalling the 110 exhaust is impossible due to a blockoff plate in the frame, above the skidplate. So, what should I do? I'm assuming that jetting is at fault here. Would dropping or raising the main needle help? It is 100% stock jetting, and the needle clip is in the middle, as stated in the service manual. If y'all think it's worth reinstalling the 110 exhaust, I can remove the blockoff plate, but would like to avoid it if possible.

Thanks in Advance

[HappyTrail]

If it's a jetting issue your spark plug should tell the tale. For instance a white electrode would mean you are running lean and would need to richen the mixture. A dark plug would mean you running rich. Ultimately you want a tan colored electrode. I could go on and on as rejeting and tuning a Carb shouldn't be taken lightly. For example there are 3 jets a pilot a needle and a main. Each one will have to be tuned separately. There a threads and websites available to help you if you're the do it yourself type. My 85 110 has a unifilter with No air box a Bassani exhaust and a 22mm Carb. Which is slightly larger than stock. I went from a #35 pilot jet to a #40 lowered the Clip on notch on the needle and went from a #82 main jet to a #90. It's different for each bike and different depending on the sea level you ride at. You should check the compression also. Anything 100lb or lower means its time for a top end rebuild. Good luck with you issue this site can point you in the right direction.