Okay. Raced at RRR this past Sunday. Race #3 - C Superstock, 8 lap race, and on lap 7 it was down on power pulling out of T's 8 & 9 particularly in 3rd/4th gears, and then really down on power on last lap out of same turns & gears. Only reason I even went to 4th was just to hope it would go, but it did the same, and I'd downshift back to 3rd hoping it would clear out whatever was going on. It would slooowly accelerate, but not the typical strong pull. It never was a sluggish pull, it literally just wouldn't pull worth a damn! Yes, I was revving it out before upshifting.... I'm not a noob. Checked the air filter first thing, and it looked good, and was told to check fuel filter next, but good rains came, so stopped all mechanic'ing, and started packing up since it was undiagnosed, and with rain I sat out my 2nd race. 2003 600RR - ~ 27K miles (last 15k are track/racing). Any idea's on what to check & look for?
Does the tone of the engine change at those RPMs, i.e. possibly a cylinder misfiring? 15k track/racing miles is a pretty good amount, even for a bike as tough as a 600rr. Ever been refreshed? Leak-down test recently done? Any electronic goodies that could be causing issues?
^Ah, yes. That makes a lot of sense too. Especially since it seems to manifest in the meat of the rev-range when the clutch plates are under the most stress.
Here's what I'd check in this order. Good Fuel Battery connections Spark plugs/pencil coils Compression Clutch wear
if it was clutch, wouldnt it be worse out of 2nd gear corners compared to 3rd/4th? i guess fueling problem.
Check fuel pressure. Clutch should be noticeable because it'll rev like normal or way faster but not go anywhere...
all that stuff above.. and verify ya have 14vt at the battery terminals when you hold 5000 rpm. if the stator is going, ya wont' have enough juice to power the plugs and injectors at higher rpm.
Okay..... ya'll prolly gonna rip me a new one.... Bone stock (OEM) motor. Still has original spark plugs & original clutch w/no slippage that I can tell, and I don't use the clutch when upshifting. Forgot to mention earlier, it wouldn't start after we'd checked the air filter. Let it sit another 30-45 min or so, and tried it again and it slowly fired up, so we then tested the battery, and it was getting a charge (~ 13 volts). Battery connections were good. The battery is 3 years old.