After draining the chaincase on my 1998 mxz 583, I stripped out the threads on one tab of the chaincase. Looking at the bolt, it appears that the bolt is'nt perfectly round, it has almost 3 points on the bolt threads, you can feel them as you turn the bolt between your fingers. All of the bolts securing the cover are like this. Why is this type of bolt used. It appears to be a 6mm x1.00 metric bolt. The threads are stripped on the case, so my thinking is to tap it out to 7mm x 1.00. I have not overtightened these bolts, and have put antiseize everytime I have removed them. I am concerned about retapping and cracking the housing. Any thoughts or explainations would be appreciated.

Thanks

There should be room behind the housing so could you possibly install longer bolts and then put a locking nut on the back?

Yes I could do that, because the location of the stripped out hole is approx the 4 O'clock positon when lookin at the chaincase with easy access. But, not trying to jinx myself, when the lower left,7 O'clock decides to strip out, putting a nut on that would be a problem because of the location. Thanks for you input! I'm hoping I could also get an explaination on why the bolts are what I would call on odd type of bolt. Also any feedback on retapping at 7mm x 1.00 from 6mm x1.00

Thanks

Those bolts (like many on sleds) are self tapping / self locking. They have threads rolled and then they are squeezed on 3 axis to distort them. The do the intended job during manufacture but fall short for those of us who routinely service the chaincase. As said, either retap them larger or install a nut behind the replacements. The stock bolts remove a few aluminium threads every time you take them out.

Thanks very much!!

The easy fix is to use a 1/4 course 1inch bolt, it will cut its own threads on the way in.
It will doo the trick. I have two in my chain case.

Thought I would pass on an update. I tapped out the threads from a M6 x 1.00 to a M7 x 1.00 and put in a bolt. Works great.