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KTM 85 sx Crankshaft Issues

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I bought a 2004 85 SX for my son so he can make transition fro 65's to 85's. the first time we raced it he took out the crank. The big end of the rod bearing went.

After doing some research I found that the 85's have issues with oil supply to the crank. I am looking for an engine builder who can match and stuff the case and also machine the reed mount to move the reeds closer to the crank. I live in northern michigan and would prefere to find somone close in either mi or wisconsin. anyone have any Ideas for me ?

He just took the crank out again last night the motor only has about 20-30 hours on it. I dont want to have to put a crank in it every 20 hours I want to fix the problem

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The KTM 85's have serious crank issues.

They are not local but I would contact Bob at WMR or Don at Pax Racing. They are very familiar with the KTM's.

Good Luck!

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Great, I am supposed to go pick up one tomorrow. Should I ditch it and go find me a KX/RM 85?

Does running a high oil ratio, such as 32:1 or more oil, and rich jetting help?

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Yes the bikes are awesome I run the oil 36:1 calls for 40:1 my kid rides F'N hard though.His 65 has ceramic bearings I'm installing them in the 85 this time but I still need the cases matched to make sure everything is perfect I hate changing cranks. Many websites mention the reed cage the only thing I can figure is if it is truly the problem that the gas oil mixture is getting pulled up into the transfer ports before it gets a chance to atomizin in the crankcase therefore restricting oil from the crank

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Ah, its speculation. I lost our big end too. A big culprit seems to be the air filter isnt fully seated in the back where you cant see it. I remove the seat, look and still feel.

I take my seat off for all my ktms and have taught my sons the same, check then double check

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I never did have an issue with the 2004 85 SX we had. My oldest son ran it good for the first part of the 2009 Cross Country season. I ran that bike like all the rest 50:1 Dumonde Tech. The guy I sold the bike to took it to the dunes recently and smoked the top end. Those sand dunes, you gota run a little rich. Plenty of KTM mini's running local without crank issues.

If I was going to have a crank re-built, I would send it to Andrew down in Texas. The guy is the most honest guy I have talked to and that means a lot to me.

Joe..........

Austinmrajacksonville18apr09+_8_.jpg

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