Silly question, what if no fuel controler?

[49Reo]

It would likely run too lean, which is bad ju-ju. I changed my exhaust out to V&H Longshots, one out each side, stock air cleaner; had installed a Power Commander PCIII prior to that; had to re-program the processor for the new pipes. Works great. The best way to know (imo) is to run it at highway speed for a few miles, then pull in the clutch and hit the kill switch at the same time. After engine quits, then release the throttle. Coast to a stop,(don't let the clutch out until you are stopped) pull your plugs,(don't burn your fingers) and look at the color. They should be a light tan to dark tan. Black indicates a rich air-fuel mixture, white indicates a lean air-fuel mixture. Also clean your exhaust tips before the ride, (wipe them out with a rag) then check them for color after a few miles at highway speed. Should be just a suggestion of black on your finger when you wipe them. These are just a couple of ways to check your air-fuel ratio; I have done it for years and works foe me. Also, any excessive popping and backfiring(more than with stock pipes/air intake) is also indicative of a lean condition. Troll and Chief, Greenbarn too, can likely shed more light on this in a simpler manner

With a programmable fuel processor, you can tune the bike with on-board adjustments, or call the folks who make the processor and they can access your bikes processor through your laptop and program it for you.

Hope all this helps; good luck and DON'T FORGET PICS of your mods....

Regards,

[Brent Duncan]

OK so if i upgrade my stock exhaust then do an upgrade/mod on the air intake/filter what is the result if i do not run a fuel controller? just preignition?