Seized Motors

[Onetype]

I've picked up a few more project bikes now that my xs400 is finished. I've gotten lucky and haven't had to deal with a seized motor until now, one of the bikes I got has sat too long and is stuck. I shot some pb blaster in the cylinders for a couple days and then filled them with marvel mystery oil probably about a week ago. I've been rocking it back and forth every day ( seems like it has made some progress but who knows), when I try and turn the crank bolt it spins but wont spin the crank. The tag says 2010 on the bike so it ran somewhat recently. Anyone have any tips/tricks?

 

[jmd_forest]

It is possible there is a mechanical problem such as a bent valve or jammed timing chain or broken piston/rod keeping the engine from spinning

 

[Onetype]

^ that didn't even occur to me, I guess it could be why it stopped being ridden. The shop I bought it from said it was left there and is stuck due to sitting. There was rust on 3 of the plugs as well as the cylinders and inside the tank. When I pulled the carbs off there was a bunch of orange fluid in them and some white powder in the carb boots. My guess would be that this thing got left out in the elements. Im not against rebuilding the motor but I don't want to if I can avoid it obviously.

 

[drewpy]

Its a head off job at least. That way its just the pistons/crank your trying to move.

 

[Onetype]

Awesome that will help, ill pull it apart and let yall know what I find. The bike is an 83 kz1100 so its bigger than what I have been used to working on so far. If my understanding is correct though I read somewhere that it uses the bs34's as well. They sure do look similar which is definitely cool.

Also I apologize if this has already been covered somewhere else, I did a search and saw that a few people have had this issue but seems like most just swap in another motor.

 

[Onetype]

Pulled off the alt cover and this stuff poured out along with what seemed to be alot of water. Looks like I may be doing a full rebuild after all. What is this stuff?

 

[eric123]

A mix of water and oil...

 

[ThePsuedoMonkey]

That's a raw deal, is what that is. Never seen an engine with a thirst for chocolate milk before! I have to agree with the full rebuild, with any luck it didn't hydrolock.

 

[Onetype]

I was pretty surprised to see that much water come out. I figure ill fill the case with MMO and see if I can clean out the inside as well as help free the pistons.

 

[bcware]

The last time I saw that kind of sludge come out of an engine the man ended up completely tearing down the engine.

Even if you can free it up you may not want to try and run it.