I need to replace my '01 crank cases & I am looking at a used set from an '04 engine. The crank case "cover" part numbers haven't changed but the crank case part numbers changed from 15100-00 in '01 to 15100-02 in '02....'05. Does anybody know if there is a problem using different year crank cases with my '01 Raptor???

 

I don't think there would be a problem. The only change from the 01 to 04 other then the tranny parts is the flywheel and oneway are different as far as I know.

 

I heard that too. Someone was trying to use an aftermarket lightened flywheel & discovered that the newer model Raptor engine internals had been changed. Yamaha sure keeps some of that stuff underwraps.
By the way sixsixt, what size Lectron single are you running? I see that Kenzcycletech is selling dual 40mm Lectrons for the 660 Raptor. I wonder if they are considered better carbs than the 39mm FCRs? They use a fuel metering rod that measures air flow, better adjusts to temp/altitude changes, & not only delivers fuel but does it much more precisely. The taper & venturi varies throughout the carb body for better air velocity. It also has a power jet & is supposed to be real easy to adjust. I guess you know all about the features?

 

The Lectron is a great yet simple carb. I first used one on my YZ 250 in 1980 and loved it.The single we used on 1badraptors quad is a 48HV. It worked OK but the edlebrock intake that we used has limitations. For drag racing I'm sure the Lectrons would outperform FCRs.