Any idea what I could be looking at to fix? Easiest way to split casings? ?

Crankshaft not moving, rod moves free, stuck in gear but surprisingly clutch works great and can move the bike while pulling clutch. There was a super long spark plug in it. Longer than I've ever seen personally. Surprisingly the piston isn't broke nor marked up etc. Cylinder is great condition. Kips not so much... lol I have tried to get bike out of gear and rocked it back in fourth in gear hoping to free up crank but nothing. The shifting rod is broken, I had to use vice grips and no movement whatsoever. Any idea on what could have gears and crank locked? I haven't tried mystery oil yet. Decided to come here first and see if maybe anybody has any recommendations. I'd appreciate it. 

Update:

Bike is a 91 Rare white kdx. 

3 Answers

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  • 3 weeks ago

    @Jake I didn't, person I bought it from did. I purchased the bike to learn the engine. I own an 01 220 and an 88 200 as well. I knew it needed some work and that I was probably going to have to split the casings. I've only seen one other bike this seized up. An old 82 Yamaha YZ100. Thank you for the help. Muchly appreciated.

  • Jake
    Lv 4
    1 month ago

    You welded your connecting rod bearings onto the crankshaft because you didn't check your oil.

    Spray the seam and gasket with PB Blaster or some other penetrating oil and let it sit for a while. Place a block of wood on one side at the seam and smack the block with a hammer (not too hard). Then put the edge of the wooden block into the seam at a good angle and try to drive the halves apart enough to make a small gap.

    Cut a hardwood wedge and try to drive it between the casing halves. Work the wedge around the seam and drive the casing apart as evenly as possible.

    I use this method on British Twins that haven't been apart in 40 or 50 years.

  • Anonymous
    1 month ago

    I'd guess a seized or spun crank bearing due to oil starvation. The sudden stoppage bent something in the transmission. Complete teardown of both is in order. Rare junk is what you've got at the moment. Not the guaranteed correct answer, but experience says so. 

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