I don't know how many of you follow the snowmobile industry, but Yamaha has dropped their 998 cc 4 banger in a sled and it has been a huge hit, especially with turbos, as 350 reliable horsepower isn't unreasonable...

We are in the process of coming up with a new project, and we thought it would be a whole lot of fun to build a yamaha eater by fitting a CBR motor into a sled and turbo charge it... The chassis would be mostly our own design, which will be designed around whichever engine we choose...

I'm new to motorcycle engines, but have sufficient experience with the less-technologically advanced snowmobile engines...

I'm not familiar with motorcycle gearboxes at all, and that is the first obstacle we'd run into. Snowmobiles mount a clutch directly to a crankshaft, so the gearbox would come off, but I don't know how it's mated to the engine...

Does anyone know where I can find some good exploded views of a lower end of a CBR engine and the gear box? Most likely we'll end up fabricating a new end for the crankshaft or modifying a current clutch design.

Also, are guys having good luck turbo charging these engines in bikes? I know they have a relatively complex FI system...

Another question, sleds are designed to endure long maximum-RPM pulls, since the CVT clutch system holds an RPM... Is a CBR engine going to hold together if held at 10,000 RPM for up to 45 seconds? Of course compression ratio's would be dropped significantly even before turbo charging...

 

Not gonna happen. Yamaha>Honda

 

would be a nice concept, but odds are its not going to work.

the yamaha 4 banger in this years sleds is alot different than the r1 motor by all means. its a lighter build, different bottom end, and many more things.

 

Yep, the R1 and RX-1 motors are a lot different... But I don't think they need to be for a mod sled. Production, yes, but not a mod...

It would be a VERY challenging and expensive project, but I would like to do it. I'm by no means committed to doing it yet, it's just an idea that I'm pursuing...

 

Oddly enough, the CBR seems to be tubo'd much less often than the other literbikes. For some reason, its just not as popular with the CBR.