broken bolt-air cleaner to carb

[bobcowan]

Originally Posted by Gunner

It's also possible that the bolt is Grade 8, but I doubt that's why it broke. The nut or bolt on an AC can be tightened down until the AC is a crushed ruin before you reach anything like the kind of strain the fastener would need to break. There's a huge amount of rubbery compression ahead of that, from the air filter between the housing plates.

8 bolts are extremly strong in tension. Yoy would strip out the threads in the carb long before you'de reach the tensil strength of the bolt.

I've made the mistake of using grade 8 bolts in places where they don't belong. Like the air cleaner. Or as part of a stand off. Over time the vibrations will cause the bolt to fracture due to lateral stress. Don't say it doesn't happen, I'v seen it/done it. Then you get a "light bulb" revelation. Switch to a 5 or all thread, and they never break.

Just one of little things I'v learned over the years.

Good decisions come from experiance. Experiance comes from bad decisions.

[RET_COP]

I couldn't really tell, but if there is 5 or 6 threads left on top of the broken piece [at least the size of the diameter of the bolt] you could loctite a stud right on top of the broken piece. It will hold an air cleaner.
Lou

[COBRA36]

Our believe a grade 8 bolt has 6 lines or marks on the head of the bolt and the others have 3. Hope this helps

[D-CEL]

You should feel Lucky, that same issue cost a friend with a BD a complete motor rebuild, a cam and a head.
It was a stud, it broke and went thru the motor.


Dcel

[springin]

I had the same thing happen while installing a brand new Demon. I was installing a stud for later removal and cut-off. Once I had the stud sized to the proper length, I couldn't remove it. It siezed and broke, luckily for me, it broke about an inch above the carb and I was able to install a coupling nut to it for a new short bolt.

I wonder if Demons grab a stud a bit more than they should,,,,, maybe some lube or teflon is the answer.