Snapping Bolts

Hi TT'rs

I've just done my 10th oil change and tightened the bolts up finger tight then a tiny bit more and SNAP :) on 2 different bolts-(1 frame, 1 oil filter cover) they havent snapped, but after winding them back out, it looks like the thread has collapsed on the bolt and squashed thin. Has anyone else experienced this problem??

Is it because they bolts are so light weight? or is it my crappy workmanship combined with the use of a cheap socket set? Should I be using a torque wrench for stuff like this?? Do I need to buy Yamaha replacement bolts?

I really hope I havent damaged the internal thread.

Thanks

Ouch, thats no good. I'd suggest getting a torque wrench is a good idea, especially since you now have an excuse ;-)

I think you're just a bit short on experience. You got lucky this time, none of the bolts broke off inside the engine. I would get the OEM bolts and put it back together, you may break a couple of more before you get the hang of it. :)

The oil filter cover is only 7.2 ft-pounds (86.4 inch-pounds) - you NEED to get an inch-pounds wrench (Sears sells one for $70 I believe (20-250 inch lbs?), this is the one that I have). As for the down tube frame bolt, I hand tighten it, then I was using 17 ft-lbs on it (according to specs), the torque-wrench didn't click yet, but I felt like it may strip so I just hand tighten it now at below the required 17 ft-lbs spec and it's fine. I was able to do the 14 ft-lbs for the crank case drain bolt with no problems. I'm wondering if the down tube drain bolt's washer is real soft (i.e. compresses a lot) or the bolt is just plain whimpy hence you can't use the specified torque or you'll strip it! :)

This is not the first time that many of us have experienced the down tube drain bolt stripping problem - beware of over tightening this bolt (the 17 ft-lbs spec may be incorrect)!

torque 6mm bolt to 10.5 Nm - cover

8mm bolts to 26 Nm - frame

Do they have Sears down under?

So why you draining the fram at the bolt in the frame?

You should be draining where the downtube bolts to the case. Quite a bit of oil is left in the tube otherwise, and draining from here empties the frame as well.

I do all 3 bolts, the oil tube bolt on the filter side and the crank case bolt are the lowest points on the bike but the down tube bolts drains the fastest...

No Sears downunder :D

I drain the oil as the manual recommends to- at 3 different places. Its never been a problem before, I never overtighten anything- its like the bolt has fatigued over the 10 oil changes that I've done so far. I think a torque wrench is on the cards :)

You need a torque wrench for sure. A must with motorcycles.

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