The time bomb has gone off! I was wondering how long it would take for the KTM to blow up. I don’t think Austria designed the 560 RFS single motor to sustain super high revs for ridiculous amounts of time, but that is exactly how I’ve been running it. That motor has seen about 25 hours of WFO running in top gear on courses that are much to big for it with a sprinkling of kart tracks in between. I always get this weird feeling when the bike is at its terminal velocity; I almost expect the piston to fly out of the top of the motor and kill me. It’s weird, I know, but that is what I think about when I’m on the banking at Nashville and other places like that. So what does this mean? I’ll tell you… project time.

Tonight I pulled the motor out and partially tore it down. I need a special cam chain breaker which I don’t have (this is the only bike I own with a cam chain!). Luckily Ed owns a KTM store so he might have something for me there. I believe I already know what the problem is before I even split the cases. These motors are, unfortunately, know to have issues with the crank. Basically it is pressed together and when large amounts of force are applied via the dirt to asphalt transition when the tire hooks up or other jolts like that, the crank becomes untrue. Once untrue it destroys the crank bearings. Not too big of a deal really, just send the crank out to be trued and then weld it together so it won’t happen again.

There is a slight chance that it is another issue to though. The bike decided to shut off and not restart while at Nashville last month. It turns out that there is a bolt holding a clamp that holds the wires from the stator to the stator cover. Well, this bolt came out and the bolt and clamp bounced around the motor destroying everything in their path. After pulling a wad of metal out and replacing all of the busted parts, including the flywheel and stator, I buttoned it back up and rode 5 or so more trouble free hours until this. I’m not sure, but I suppose this could be related.

This has given me the opportunity to rebuild the motor and a couple of other things. I’ll probably go with a high compression piston, set the squish properly, valve and head work if needed, full exhaust, etc… As well I’m going to send the rear shock out to have it setup properly for me. There is a bolt missing from the collar… not sure how that is possible, but I think I’ll replace that as well. I’ll probably get some new gearing and a chain for the kart tracks. Currently it is just too tall for short tracks… using second gear only isn’t that much fun. I think I’ll try to keep this bike on short tracks only if I can next year. We’ll see though since I was thinking about doing some WERA racing in the motard class, which would require me to get out on the big tracks.