Is this repairable?

BrandonH

New Member
Jul 23, 2014
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Plant City, Florida
Ok so as some of you know, i had a air leak I was tracking down, I finally narrowed it down to the counter balance shaft.

So after I split the cases, I saw what looks like something steel got squished between the counter balance shaft and cases, and looking very closely it has a hairline crack in it. I am not sure what this is from, because all the bearings look great and are smooth, and no needles are missing from the other bearings. I haven't rode this bike yet so this is something that happened with the previous owner.

Pics below. Is there any way to fix this? Tig welding or brazing? I don't believe its a high stress area. If not and I am forced to buy one, can I just buy that side or do I need matching cases? The stator side of the case was not touched at all and in great condition.

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In my experience that's a common area to get damaged with engine failure. I have mix matched cases and the engine is fine. Right side cases are pretty easy to find and are cheaper then stator side. I'm not sure if it would be cheaper to fix or replace.
 
Id have some one TIG it. Its not a machined surface so to just have it welded shouldn't cost you much
 
Yep, that's what happens when broken piston chunks get between the rod and the cases. Since most destroyed cases are the stator side from a chain whack, there should be plenty of orphaned right case halves. I wouldn't screw around trying to fix it. Make sure you lap your cases before you put it together. Unlike Banshee cases, Blaster cases do not need to be a matched set.
 
Blaster cases are definitely not a matched set an are even sold new from Yamaha seperatly, but i would have that case tig welded an then clean up the weld an lap the cases, itwill be fine after that, ive had way worse then that repaired, an have had no issues what so ever.
 
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I repaired one like that not long ago at all and I ground it down, Welded it Then ground it smooth. No problems what so ever. Make sure it's smooth and even.
 
If he wants to solder it he has no idea what he is doing. Have it tig welded, its the easiest, safest, strongest repair. With soldering or brazing your heating the case in a large are which can distort the whole case, tig puts quick high heat only in the area that the weld is, an it cools quick, no distortion, you can clean the weld up with a carbide hurtin bit or a file or even sand paper, an them lap the case halves, an done, no questioning the integrity of the repair or guessing as to how long it will last.
 
I have repaired holes in 2 stroke cases with JB Weld epoxy with 100% success.
It is not under any stress, temperature is under 220F and pressure under 10psi.
Welding or soldering is fine too if it doesn't warp the case. Always good to glass lap it after.

Steve Best