I mentioned this in another thread from general discussion but this really deserves a thread of its own..
So I have an '82 Suzuki FA50 that I bought a while back. It was leaking oil from the base gasket and only lasted a couple of days before the engine seized on me and I could not get it started anymore. On disassembly I found that the first piston ring was seized.
Anyway, I had the cylinder bored/honed to first oversize, ports expanded, and head milled down. Before the engine seized I was able to pull almost 30mph out of it. After this build I can only get it to go about 25mph tops and I was hoping the build would give me more top-end rather than just extra torque.
What’s weird is it seemed to be running rich straight-out after the build with stock carb jetting. It responded negatively to any up-jetting and actually worked better when I kept the stock jetting and replaced the airbox with a high-flow air filter.
I'm wondering if anyone has any experience tuning these bikes and knows how to get more top speed out of it. Are there any larger carburetors that are compatible with it?