I have an 86 trx250r and i pulled the left case cover off to get some water out the other day and found a broken bolt inside there. Its the left(front side) bolt that holds the counterbalancer? cover. Its about 5 or 6 inches long. It broke about 1/4 of thread off in the hole. Is there anyway to get it out without tearing down the motor? Any help would be appreciated.

 

My 86 broke 2 or 3 of those bolts long bolts on the counter balancer cover. If you replace the bolt it will probably just break again. The remain 2 smaller bolts will still hold the cover in place. I would still leave the broke piece of the bolt in its place or otherwise the part left in the thread will eventually vibrate loose and interfere with the stator and flywheel. After several rides the 1/4 piece of thread will easily come out and you can replace the bolt without disassembly.

 

My friend has never broken the bolt, but has broken the dog ears on the CB bearing carrier about 4 times. Once on the stock one, then has broken 3 of the Pro Design Billet Aluminum ones. I would just do what machwon told ya.

 

td250r,
That bolt breaking is very common on 250R's. Just remove the broken part of the bolt and put some silicone in the hole to keep the threaded end of the broken bolt from coming out and getting stuck in you flywheel/stator area. This happened to me one time. The threaded end vibrated out and got caught in the flywheel/stator, took us an hour or so at the dunes to figure it out..[img]i/expressions/face-icon-small-smile.gif[/img]

 

it has already backed out a little. so it wont end up in the motor? it should come out the bolt hole after so long? thats a good thing, because i was about to tear into the motor. thanks for the help.

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86 trx250r-port and polish
97 warrior-stocker

 

You can try using a scribe or a left handed drill bit(at least 6" hard to find!!!) to get the piece out. I modified a 6" #30 (.128&quot drill bit into sort of a left handed drill bit(ground the flutes flat then reshaped them more towards a left handed grind) and have good luck getting the piece out.

The reason that the bolts breaks is open to some discussion. Part of the reason is that bolt is so long. A long bolt like when tightened is very easy to over torque. The torsion force applied is absorbed into the shank of the bolt and then that force then overvalues the torque. Another theory and works well with the previous, is again the length of the bolt. Harmonics from the engines vibrations cause it to break.

Here's some tricks that have worked well for me are:
-Use blue thread locker (med strength)on the threads.
-Liberally apply silicone to the shaft of the bolt.
-Install the bolt and tighten to just snug, not tight-tight.

The thread locker will keep the bolt in place. The silicone will dampen any bad vibes there may be.

 

Mike330r, I would just like to say that i love the pipe i bought off you on ebay.Thanks

 

Glad you like it! You got a good deal [img]i/expressions/face-icon-small-smile.gif[/img]