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View Full Version : HELP....1981 atc 250r bottom rod bearing



Lewis250rMan
06-12-2013, 08:04 PM
I need help. I don't know how to change the bottom rod bearing on my wheeler. I was riding it and all the sudden it tried to lock up. Thought I blew out a ring in the cylinder and was sure I put scratches all up and down the cylinder. Took it apart and the bottom rod bearing had blew to peices. There were metel shavings getting stuck. Not letting the crank move freely. And I'm wondering if anyone knows how to change that bearing?!?!?

RIDE-RED 250r
06-12-2013, 08:28 PM
You will need to do a complete engine tear down and remove the crankshaft. Unless you are a machinist with the proper press and jigs, rebuilding a crankshaft is something you will have to have done at a shop.

The crankshaft must be pressed apart to replace the connecting rod/lower rod bearing. And consequently is must be pressed together, PROPERLY aligned.

So, since your lower rod bearing failed, you will likely need the crank fully rebuilt as the crank pin is likely to be toast as well.

Or, you could seek out a new rebuilt crank assembly. Hot Rods has a good reputation. Just need to look and see if they offer cranks for the air cooled R. If so, it's as simple as just replacing the whole crank assembly.