Hole in my crank case?

[twind]

Hi
I bought a new 2001 TTR-125 for my son, he road it for about 15-20 hours, the chain got loose and
came off, then got jammed between the sprocket and the case. It knocked a 1/2" x 1/2" hole about
wide as the chain in the case.

We did nothing with it for 6yrs except spray wd40 in the cylinder.

I priced, to have the case replaced,and it was 8 or 900 with labor, so it sat.

Someone told me to take the engine off the bike and clean up the hole with a small
file or grinding tool, then fit a new piece of aluminum to the hole and jb weld it in. The hole
is on the edge of the case where the cover meats the case. Will jb weld hold it?

 

[junkjeeps]

Pull the side case and see what is behind that section. I had a trx125 4 wheeler that had the same problem and the spot you're talking about was just a void in the case. I filled the whole thing with JB weld and it held just fine. Once JB hardens, you can file and shape it just like metal. You really don't know what you've got until you disassemble and look at it.

 

[IndyMX]

A flat tracker friend of mine has an XR500 motor in his bike that has more JB weld & Silicone sealant holding that thing together than it does bolts.

When it springs a new oil leak, he gets out the JB.

Do like junkjeeps says.. It very well could be a safe fix.

 

[snb73]

If I looked up the right part, Bike Bandit has the side cover for $80.

http://houseofmotorcycles.bikebandit.com/parts/Yamaha/TTR125LN/2001/407377

 

[twind]

The hole is not in the cover, it's in the crank case where it meets the cover, but thanks

 

[Rotorranch]

Got pics?

Got the piece that got broke out? If you have the piece, you can get it welded.

If it's just between the flywheel and the chain, and not into the inside of the cases, it would be an easy fix.

Rotor

 

[TWRT]

I had an IT425 that jumped the chain and knocked the shift shaft out of the bottom of the engine. I bent the shaft back and jb welded the hole and around the shaft. It ran for years, until the connecting rod lower bearing locked up.

 

[Cabot]

Same thing happened about 2 years ago on my XR100. I used JB weld, and to this day it is still holding.

I'm pretty sure I used some plastic off a coolwhip container, or something like that to make a mold for it, so I did not have to file anything major. If I remember right, the plastic came off easily. But I do know the JB weld fix worked great.