Nice one. You gonna ride it on the dirt at all this summer?
As a matter of fact I am. That is due to the fact that my Thumper Racing KTM 520 went down again which is what moved up the YZ purchase.
I was going to start a Thumper Racing thread but I just decided to reduce my stress and let it go. I called Travis then sent him an email which he has chosen to ignore. In a nutshell here is what happened.
I sent my motor to TR to be rebuilt as a 520 a few years back to the tune of $2200. At the time I told Travis I was building a snow bike and he assured me he had lots of snow bike motors out there and this was going to be the bomb. It didn't even last one season before the con rod went out in less than 40 hours. I sent it back and they rebuilt it again at a discounted price of $1k. less than 20 hours of DIRT ONLY runtime later the motor has cratered again. This time I tore the motor down myself because I now have the time. What I found was TR originally installed a 7mm wide crank seal where KTM calls for the 4.5mm wide seal on my year of bike. The boss that the seal rides in on the case half measures 5.7mm tight to the main crank bearing, that's with no clearance to the bearing. The 7mm seal cracked apart because it was unsupported on the outer surface or they crushed it to get it in there flush with the boss in the first place. Bits of it went through the motor taking the oil pump gears with it and subsequently the rockers, piston, con rod and finally it dropped a valve.
I talked with Travis and he claims its not his fault and that they use that seal in all their motors, well I'm telling you right now there is now there is no fawking way that seal can fit into an 08 XC4 motor. The 08 has unique crank, case halves and seals.
The oil jets were plugged with rubber seal bits so all bets are off as to how long a con rod will last. Once the single sump conversion was done it allowed material to go where ever it wants without necessarily going through the screens or filter. I found $hit everywhere in fact the oil filter was spotless no material in it.
You can tell by the bits of seal material that it had been spinning in the boss for some time. The larger pieces were still between the freewheel and the case on the crank. KTM calls for Loctite on the seal, no Loctite. How they didn't catch it on the second rebuild flat out baffles me. Every time I call them there is some personal drama or other going on down there so I never got the feeling anyone was doing a good job vs just trying to get it out the door.
Long story short, those guys are hacks so save your money don't big bore and don't ever let those idiots touch your motor. I gave them the chance to do the right thing here but they have chosen to ignore me. Buyer beware.
The pics are of the seal pieces as they came out, that didn't happen overnight and of the case half. The last pic, although kind of blurry is of a 4.5mm seal as spec'd by KTM. It just fits in there.
M5
