Hi,

I have just bought a gsxr 400 with slip on K&N filters and a stubby micron oval end can. Due to the noise I've changed back to a standard end can which has made the mid-range rich. Top end is ok once it has cleared but the can is blackened with the over rich fumes. Anyone have any ideas. I've thought about lowering the needles to lean out the mixture and wondered if this will do the trick?

Thanks
Deacfo

Needs smaller main jets surely, but I am no expert by any means

That was another option. After inspecting the plugs only cylinder number 1 and 4 are running rich while 2 and 3 are fine. I'm going to try the needles and take it for a test. Hopefully it'll do the trick, if not its back to the forum