It's occasionally falling out of 6th gear at high RPMs under acceleration. It started mid-way through last season. We've since re-built the engine, so inspected the gears and shift forks -- didn't see any problems. We put a Factory Pro shift star on it with hopes of improvements. I'm using standard shift pattern with a Bazzaz quick shifter. Any ideas?
You need to replace some gears in the transmission. Hard to believe you did not see rounding of the shift dog ends when it was apart.. The forks do not hold the gears in position, they move the gears into the correct postion and then the pressure on the dogs and corrisponding slots the dogs fit into lock them in place. Once the dogs are damaged they will continue to slip and it will jump out of gear repeatedly. It very well may have damaged the forks and the shift drum, but as a result of it jumping out, not because they caused the problem. Time for a tear down and proper inspection.
I appreciate the info and advice. That said, I've heard that there's something specific to this model year of CBR that's causing an issue on some race bikes. Any model-specific advice?
Not me but then again I send ALL my trans work (after the trans is out of the cases of course) to R+D Motorsports in Fla, they are the best trans (only) shop period. They know what breaks, why it breaks and how to fix it on ALL models. They hardface weld and heat treat in house. Gear dogs are index matched to mating gears for perfect alignment. Over and undershifting (gear travel) repairs are old hat to them. The line if front of your project may be measureable and you have to take your turn, but once your bits hit the bench, they get the work done in no time. I can't say enough good stuff about these guys, they really do rock and their knowledge base on cycle trans issues and repair is limitless. http://www.r-dmotorsports.com/contactus.htm
I know just what you mean. I HATE to go back into one that I've had on the bench.. But now you know something you did not know before. Once a trans starts to jump out of gear, parts have to be repaired/replaced/race-prepped or it will just get worse...
Tunersricebowl, he JUST had the engine completely built by SDS like 100 miles ago, one would think that his engine guy would have seen that if its the case, and the FP Evo shift star works well, but it is a band aid. This is VERY typical of the 07+ CBR600RR with 5th-6th gear..its not a wear issue. more a set up issue. maybe its because his CBR is making "131rwhp"
