hello i have a cr80 engine on a drift trike i built and I’m looking for some info on the tm28 carb , i have a mikuni single outlet fuel pump that i will be using to fuel the carb i was wondering if someone could help with needle and seat size and jetting to get me close to what ill need to run with the fuel pump. its a stock cr80 motor. also what is the difference between the tm28 and tm28ss ?thanks in advance.
I assume you would be running pretty much WFO all the time like we do in karts. When plumping the fuel system, put a tee fitting in the fuel line just prior to the carb, have the tee fitting facing upward and route that line back to the fuel tank. Your fuel pump will deliver more fuel than your carb will need, the excess will be routed back to fuel tank.
The difference between the TM28 and TM28ss is the choke lever, the TM28 has a brass lever to activate the choke, the TM28ss has a black pull button for the choke. The TM28ss is the preferred carb.
As far as jetting, I run a 195 main with a 37.5 pilot with a K&N style air filter.
Hope this helps,
I assume this is a low slung trike, I can’t see it any other way.