| Author | Message | ||
     Reepicheep |
I got a second bike, a 1985 KLR 250. This is a single cylinder 250 CC water cooled overhead cam bike. Old, but the design was ahead of its time. Anyway, I just re-geared it. From a 15 tooth front to a 13 tooth front. Much better for the dirt. But on the street now, when I hit 65 MPH, the poor little thing is up to 8500 RPM. Thats still well below redline, which is 9500 or 10000 RPM, but it sounds... wrong... like the poor little thing is getting its neck wrung. So what kind of durability implications will this have? The sprocket is easy enough to change that I can trivially swap them (even mid trip, if I want to ride to the trails, ride the trails, then ride home). So I don't need to wind it out that far. But if the only thing I really give up is a little fuel economy, and am not really compromising durability, then I might just live with the high revs at 65 MPH. 8500 is a LOT of revs though, at least for a Buell. But 250cc's is a pretty small piston, and the bike has a pretty light flywheel, and it is overhead cam... What are peoples thoughts / experiences? is 8500 that much worse for durability then the 7500 or so it used to turn at that speed with street gearing? Thanks for any insights... | ||
| Mbsween |
Reep, Kawi's are meant to have their necks wrung. I routinely have my L3 (1983 750 IL4) at 9-9.5K. It takes on a new sound up there which I happen to like. Did I mention its pushing 110k on the odometer? I'd think bar/peg vibration would be the issue. I road a DRZ 400 from San Diego to Tecate Mexico all the time trying to keep up with a VFR. I had that thing up to an indicated 92 MPH. My hands were falling off from the vibes. That said you'll want to check cam chain tension and valve adjust as the manual states. Other than that it should do those RPMs all day long | ||
| Natexlh1000 |
I beat on mine with the stock gearing. I ran it at 7500-8000 on the highway regularly. The top end lasted about 18,000. | ||
| Reepicheep |
Cool! Thanks for the real world data. I'm hoping the vibes from the knobbies cancel out the hand numbing vibes from the motor... just gotta keep them out of phase  | ||
| Bombardier |
Get your hands on a print out of the torque and power curve of the bike. Where you ride it the most is where you want the most torque. The fun bits ( riding in the bush ) can be accessed by downshifting for more power. If you want long life then operate in the torque area. If you want short life then operate in the most power area. A thousand revs does not seem much but the forces exerted on the components rise exponentially not linearly with increased revs. | ||
| Swampy |
I rode a 650 Ninja the other week, I had a hard time using all the revs, man I just can't get myself to wind it out that far. The good thing about that bike is it didn't seem to miss all the high RPMs, it just pulled along below 8,000RPM just fine and had a nice linear torque curve, no suprises. |
