Please help!! Kdx 250

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Spetty
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Please help!! Kdx 250

Post by Spetty »

Hey everyone. Just wanted to ask someone about welding a very small hole up on my gear box behind the front sproket. It is about the size of the tip of a pen. (The writing end.) I'm a perfectionist and it bothers me. Bike is new to me. It's a 1994 kdx 250. Thanks for any advice.


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Please help!! Kdx 250

Post by SS109 »

Just find a competent TIG welder and have him fix it. No biggie.
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Spetty
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Re: Please help!! Kdx 250

Post by Spetty »

Ok thanks so much. I had heard people say you can weld that stuff because it could ruin it and others said it wasn't a big deal so I was lost.
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Please help!! Kdx 250

Post by SS109 »

If it is aluminum it can be welded. The only time it becomes complicated is if you have a crack/break through a surface that holds a bearing, race, or oil seal.
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Spetty
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Re: Please help!! Kdx 250

Post by Spetty »

No, my case has chain damage but it looks like the chain has grabbed something or possible come off and bunched up around the front sproket and punctured a very small hole. I just want to repair it properly.
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Re: Please help!! Kdx 250

Post by newbbewb »

the quality of the alloy in the case material thrown in with the oil can make tig welding difficult. it's not like MIG where you can blow through some light oils and dirt. A guy CAN weld the case, just not pretty. For example, I blew the backside of the right side case at the kickstarter. Really wanting to ride my new-to-me kdx, I had my rather experienced buddy reluctantly TIG it after commenting on the metal soaked oil. He got it kinda patched up enough to use it, and after smearing some RTV on it cause I HAD to ride, it still leaked a bit. He told me not to tell anyone that he did that. LOL

IMO, crack the cases, clean the HELL out of the area to be welded 3 or four times, inside and out. MAPP gas the area as to burn anything paint or solvent/petro based. buy a DEDICATED TO ALUMINUM ONLY small wire brush and scratch everything up to be welded. DO re-use a brush thats been used on steel. now that it's CLEAN, you are ready to attempt to weld.
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Re: Please help!! Kdx 250

Post by Spetty »

I didn't know it would be that meticulous. I can't afford to crack the case right now. I guess I'll just jb weld it for now. Like I said the hole is so tiny.
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Re: Please help!! Kdx 250

Post by newbbewb »

Good idea. JBweld would be my bet next time in a pinch, not RTV. I'm going to throw some in my fender pack right now, seriously. clean the are to be JB'd real well and coarse grit scotchbrite,

I'm really not trying to be debbie downer here, but just so you know about this aluminum casting is a pinhole on the outside is a crack on the inside. It will keep growing.

If you do decide to pull it apart and weld it,if you can locate the cracks on the outside of the case after scratching it up with scotchbrite, drill little tiny hole at the very end of each crack to relieve it. Then weld the piss out of it.
93 kdx200-Highly modified
89 kx125/kdx200E engine
Buelldustin@gmail.com
Spetty
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Re: Please help!! Kdx 250

Post by Spetty »

Well that's not good to hear at all. I would think it would be cracked on the outside if anything? But I don't know. Would trying to clean it very well then having it tig welded up be a better option than the jb weld? I'm just not up for splitting the cases right now.
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Re: Please help!! Kdx 250

Post by newbbewb »

The case alloy is strong, but brittle. It wouldnt suprise me if there were some small alloy chunks inside the engine. do you have a picture? have you scotchbrite the area around where it broke? that will highlight small cracks.

That being said if it was MINE, and I had to ride NOW (which has happened more than once) I would most definately weld it, engine together. drain oil, flip bike on side, clean, clean, clean and weld her up. JB weld would work, but I would be worried about dirt and stuff that gets wrapped around the output shaft gettin stacked up and wiping the JB weld off. also consider how much heat is being put into the case metal and the nearest rubber item, because the welding can and will melt output seals and such. Might want to have new ones ready
93 kdx200-Highly modified
89 kx125/kdx200E engine
Buelldustin@gmail.com
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