What was up with the case replacements?
Well, here is the history and my theory:
I bought my Dale new, pre-bankruptcy, in Nov. 2001. It was one of the "tweener" Cannibals with red/black plastic, cable clutch, and Ohlins shocks. It even had the bronze colored side cover with Torx style bolts and MC500 computer with the cam sensor.
I rode it one time, maybe 2hrs, and took the front plastic off to check the air filter. To my surprise, there was no air filter! Long story short, Cannondale replaced my motor and ECU with no questions asked. Actually they gave me a choice; either send that motor back to them and they would do a factory inspection/rebuild or they would replace the motor. (Cannondale was the greatest company ever. I could call the factory techs direct, without having to go through a dealer!)
I rode it pretty hard for a couple of years until all of my engine oil got sucked into the tranny. That was when the first cracked case was discovered. It had cracked in two places; radially out from the stator side crank bearing, and in the narrow section between the crank and the tranny. I ended up getting a new case from MAZ (another long story) that was a cable case. That one lasted maybe a year and cracked in the narrow section again. At that time, the motor mount issue was being discovered and so I added Boomers kit hoping that would solve the problem. While I was at it, I upgraded to the hydro clutch case because I wanted the Magura clutch and they were cheap with the liquidation and all.
By this time, I had been racing a few WORCS races and raced local CC and MX events. This new case lasted about a year. It cracked radially from the stator side crank bearing. I, of course by this time, was pretty well frustrated with the whole thing, but I bought another hydro case and had S&S Motorsports swap everything out and check everything and dyno it.
Now for my theory:
I have done all of my own motor work on this quad up until this last case. Also, I had the crank replaced during this last rebuild. My theory is that the crank had way too much endplay in it, as I didn't really check it because I didn't have any good means of doing so. It felt pretty sloppy and I think the vibration was causing the cases to crack. I'm hoping that with having Kenny at S&S rebuild it, (he owns/races ATKs and builds several of the NW WORCS riders motors, all brands) and getting the tolerances correct, that it will not crack anymore. It did seem to be noticibly smoother when I got it back.
Now, I'm just so burnt out of having cases break, that I'm a little afraid to race it anymore (plus I'm getting old!) so we'll just have to see. I let a 14 year old kid race it a couple of weekends ago in a 42 mile, wide open GP race and it ran good the whole time, so I'm keeping my fingers crossed!