Fzr Carb Jetting

[dwilson]

My first CCS weekend of the season is at Summit in 1.5 weeks and my jetting is a bit off. I plan to get some jets and tune it in this Sunday at Summit. Here's what I got... 96 FZR600, Slip-on, K&N air filter, 5 degree advanced timing, trimmed air stacks 1&4 in the air box for better flow, I run pump gas (track only bike).
After I put the K&N filter, slip-on & 5 degree advancer on I had it re-jetted with a Factory Stage 1 kit (110 mains), that was in the fall and it ran well (dyno said 85 horse!). I then trimmed the # 1&4 air stacks in the air box from about 3 inches to 2 inches & changed the spark plugs (identical replacements). I also routed the carb overflows into the airbox. On April 6 at Summit it ran like crap. It idled fine, ran around the pits fine but above 6 or 7K RPM it had no power and was breaking up hard.

I pulled the carb overflows out of the airbox. The spark plugs are very clean, the ones I pulled out from last season were fouled looking. The current jet sizes are 52.5 mid range & 110 mains. I ordered sets of 55 mids & 112.5 & 115 mains. I should have looked but I'm pretty sure the needles are not adjustable. I suspect the jetting was done with fouled plugs. I figure between the seasons changing, better flow in the air box & new plugs it's lean again. I plan to up the mids to the 55's & the mains to 112.5 and take it from there. Does this sound like a reasonable plan? Any input, criticism, cinnicsim or other input would be appreciated...

[Super Dave]

Mid's...  You mean pilot jets?

If you got a Factory jet kit, it should have adjustable needles.

But you've got to get the main right before you mess with everything else.  Did you follow the instructions or bother calling Factory?  They are pretty bright guys out there.

If you over oiled the K&N, it might not flow as much air as the stock one.  That could mess up your life.

[spyderchick]

Have you synchronized the carbs? All the jetting and rejetting can be for naught if you forget this one step. Also, the airbox needs to be on securely, that little bit of "leakage" can cause the bike to real run poorly. Good luck and let us know what it turns out to be.

[dwilson]

I have not oiled the air cleaner.
The air box is secure.
The carbs were in sync before I started messing with it, and I checked for vacuum leaks (all was OK).
Calling Factory is a good idea, working in computer support I keep forgetting that it is possible to call people and not have an idiot on the other end of the phone...