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HardTaco
2/12/2017 9:08pm
2/12/2017 9:08pm
When the bottom end was done 45 hours ago the left case was apparently damaged. It's hard to tell from the picture but the bottom 1/3 of the oval around the crank seal is cracked and leaking. The crank is still tight as a tick, piston was even in very good shape. I can't find a good used left side case on ebay and my cost on new is 350.
Call me crazy but I thought about just removing the left side case, getting it welded by a bud who is experienced in welding aluminum, then popping in a new bearing and seal and calling it good. Anyone ever done this before? Any tips?
Call me crazy but I thought about just removing the left side case, getting it welded by a bud who is experienced in welding aluminum, then popping in a new bearing and seal and calling it good. Anyone ever done this before? Any tips?
I wonder if having the extra flywheel weight hanging out there on the end of the crank could contribute to this ?
The Shop
If it is a relatively small crack (I assume it is because we can barely see it) then you shouldn't have much of an issue because it will be a single pass with a small bead. TIG will be able to fill it with a small piece of filler rod, and a stepped welding sequence will prevent any warping. It is a larger piece of metal so it shouldn't be noticeable unless your welder is careless with heat and rushes the cooling process. Patience is key.
Let us know how it goes!
Pulled the flywheel and saw the full circle weld, and it had failed. I have no idea how many hours were on that weld before I purchased it. But it failed in short order for me. Couple hundred hours on a used ebay case since then with fresh bearings and no problems. No idea what caused it for the previous owner or why the weld job failed. But fail it did for me at least.
I have since collected a few cases halves off ebay and craigslist. Nearly have all the parts for a second spare motor I hope to build to X specs. They do show up, but most good ones seem to go for $150-200+ these days. 99-01 will also work and seem to come up priced a little more reasonably (You just need to bore the swing arm bushing out slightly to accept the larger swing arm bolt. Plenty of material there to do it). I have a 99 left case on the motor currently installed. Personally, I'd be tempted to go new if you can get it for $350 over a $200 used one.
Good luck!
Pit Row
Josh
You can see where it split in the case, might be a bad casting lodged piece of dirt 💩 or something else, that looks harder than the surrounding material. I wonder if they have pictures that they can match, the study of cracks Oh my God it's one of those cracks!! $$$$ it's going to cost you.
I forget what we had in the material some stainless steel and we couldn't do anything like drilling and stuff, like what the heck is going on? And it was a bad run off the mill, had crap mixed in the there real hard stuff the drill bit just shattered against it, and the plasma cutter couldn't cut it, it was through the entire batch of it, all of it was garbage, it was suppose to be certified as well.
For sure weld it, have the guy make a small v to fill it in, that way you are getting a little deeper into the material instead of up on top of it.
Lastly, when you go to service the bearings, heat up the cases in an oven @ 350 degrees until the case is smoking pretty good, (20 min+), and remove the cases and smack them down on a piece of pine board so it's soft and the bearings will fall out. Then place the replacement bearing in that was sitting in the freezer over night and it will fall in. If it doesn't fall right out, you could give the bearing a few taps with a bearing driver.
99.9% of the time, no hammers, they fall right out and drop right in.
Let cool down naturally and then you can assemble.
Good luck! J
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