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Stress crack?


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I ripped my motor apart and got to the crank. Everything is nice and still tight. This is the first time I tore it apart. It ran great for 3 yrs. Compression was gettin low so I tore it all down put new seals and pistons and what not. I noticed on my one side of my crank on the web ( the main part of the crank where the rods go in between) looks almost like a slight stress crack. I'm trying to get a good pic but wondering if u guys even had this. Wondering if I should still use this crank. It goes about 1/4 away around the circle. Unless it was rubbing I'm not sure. I'll get a pic up asap.

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here is a pic... i touch it lightly with a nail file and it just looks like maybe something from when it was dismantled maybe by previous owner or what not.. looks almost like it was peened over a little.. ran perfect for last 3 yrs probably just go with it..

Really bad pic man. I can't see anything on it. It's kindof blurry.

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i can barely make it out....but i see what your talking about......i'd take it to a quality engine machine shop and see if they can magnaflux it for you. it will be an absolute sure way to tell...that way you don't grenade an entire new top end along with your bottom end. Its not expensive and it will only take them a VERY short time....like minutes. the only reason i suggest that is that it looks like the line zigs and zags back and forth like a stress crack as oppose to a scratch from disassembly...

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What happens when they magnaflux it

 

they magnatize it then put metal powder on it and it won't stick to a crack, a scratch it will , worth the effort to not take out other parts later. I think it is a crack,to jagged to be a scatch

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like toytech said....they put a really really strong magnet to it and use super fine metal powder...it makes ANY crack stand way the hell out.....its a sure test to see if its a crack or not. the cracked edges actually wind up acting as a N and S pole and display the crack in the powder.

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looks like a normal casting mark to me. what you do is- spray it with wd-40 or pb and let it sit a min. then, spray a little bit of brake cleaner on a rag and wipe it real quick. not scrub, but just wipe the oil off, and blow on it. if it's a crack, the oil will soak in, then seap back out and you can see it. you can sometimes do the same with just brake cleaner as it flashes off, the crack will be the last to dry. don't froget to re-oil the crank when you put it in.

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