BannedCR500Riders.com

I decided it was time to start the engine rebuild of my basketcase and ran into a little snag. I knew that the rod bearing had gone south when I took the jug off, but I didn't know to what extent.

Today I split the cases and found that the rod had acquired enough freeplay to hit the crankcase prior to its sudden stop. On the left crankcase, there is a small hairline crack directly between the tranny and the base. The is also another hairline crack on the bottom of the case a little in front of the bottom motor mount. The right side case has a similar crack near the bottom motor mount. All three cracks are very small, not more that 1/4 inch in length. I slid the cases back together and the mating surfaces still appear to be good.

Is there any issue with just cleaning these cracks up, grooving them a little and putting a bead of weld on them? Anyone done this before? I don't think either area would be subject to real high stress. I momentarily considered some JB weld but I want to fix this right. Anyone with some ideas.

Also I do not have anyone in the area that is what I would consider "Good" at welding aluminum. I'm sure I can mig the cracks well enough to seal them up and grind them down myself.

Needless to say my $500 basketcase is going to get a whole lot more exspensive if I have to buy new cases. HELP!

I put a 1" hole in the cases of an 83 CR480 years ago, my dad tig welded up the hole then machined the gasket surface and they worked good as new.

There is no one in my area that can tig that I am aware of. Would there be any significant stress on these areas when the engine is running other than vibrations? It would seem that the crank bearings would be taking all of the force from the crankshaft.

you can tell where all the high stress and load areas are because theres extra material and some gusseting- around bearing areas mainly and crankcase deck. sounds like your cracks are in less important areas. should be a simple weld and grind

I've "Repaired" small cracks and holes by drilling it out, and threading in small aluminum pipe plugs like this...


..........Your mileage may very.

AlisoBob wrote:I've "Repaired" small cracks and holes by drilling it out, and threading in small aluminum pipe plugs like this...


..........Your mileage may very.

Hey there......Speedway is a customer of mine.