Cross-threaded bolt found during oil change on my YZ426

From what I remember my last oil change went without incident three rides ago. Then tonight while preforming another oil change as I backed out the three bolts that hold on the filter cover I see engine block shavings coming out on the bottom bolt (the allen headed one). The threads on the bolt don't look too good either. I don't know how I did this cause I always run bolts in with my hand and don't use the ratchet until it's seated. So I run a tap into the hole and then clean the bolt best I can. It seats and tightens sort of OK but feels weak. Should I go a size up on the bolt and re-tap the hole a bigger size? Or will just a fresh bolt the same size be OK? Also if I re-tap the hole is that an oil port through the bottom one and what about the shavings I'll create down in the casing?

Remove the side cover (you dont have to split the cases luckily) and heli coil it. I had to helo-coil my lower oil galley bolt on my rebuild and it took 10 minutes and holds like a champ. Do not do it with the cover on the bike though as you dont want to risk contaminating the motor with alum shavings. Good luck!

I don't know how I did this cause I always run bolts in with my hand and don't use the ratchet until it's seated.

Not your fault, you didn't cross thread it.

Debris and oil from the filter cavity actually drain out that bolt hole. It is common for this stuff to bugger the threads in the case.

In the future clean this hole w/ a shot of WD-40 or something. For now stick a heli-coil in there as was already suggested.

Good luck.

All the information you have gotten so far is "Right On". :banghead:

I'll add this one point;

Put "Never Seize" on the bolt threads every time when re-installing the bolt.

This will keep it from happening again. :banghead:

I have three bolts so far, this has done the trick, its not usally the casing so try a bolt first, its much cheaper...good luck

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