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View Full Version : Changing crankshaft pin... motor rebuild! 84 250r



roger86200x
08-26-2008, 11:24 PM
Hey,

I seperated the cases of my 1984 250r and got the crank out easily....to find the main bearings shot.... got those coming now too...

What oil goes in the bottom end?? I know its gotta be either regular oil or some heavy gear oil....what is suppoed to be run??

I got a new connecting rod and bearings/pins kit and need to install it now...

The crank is out completely...

How do I get the pin out of the crankshaft to change the conencting rod?

What direction does it come out? Go in? (stator side to gear side or the other way around??

ALSO, what do I need to check while Ive got the cases seperated? All the bearings seem fine except the main ones....they are coming...



Thanks,

Roger

toocheaptosmoke
08-26-2008, 11:30 PM
The crank needs pressed apart, then set back in phase when pressed back together. Usually you have to take it to a machine shop to get that done, unless you have all the tools. As for oil, 10w40 atv oil is what I use.

tecat-z
08-26-2008, 11:36 PM
Yes, a crank "jig" or "fixture" is needed. And runout has to be kept to an absolute minimum. This is one procedure that is best left to a professional. If you want it done you can look up crankworks. Think a basic R&R of the rod is $70 or so. Plus the cost of rod kit. Remember, it's the heart of the engine. And very important to be done correctly.

roger86200x
08-26-2008, 11:41 PM
I figured so... Im dropping off the cylinder and ..umm "head"/dome at a local machine shop to be bored out and cleaned up...

I'll drop the crank off too... better to do it right...

What do you call the "top" of the cylinder on a 2 stroke? Head seems wrong...

Roger