OK. Here's the deal. Yesterday I went snowmobiling, and the engine seized in because of a ripped off water hose. Here's my question...how do I take the pistons out off the cylinder??? And is the Rotax 440 LC with sleeves or Nikasil coated? I hammered the piston to make it move...but nothing. I want to take it out to see what happened in the cylinder walls (and change everything broken!!)
Thanks for any help.

 

With an engine completely seized up it's pretty much BY ANY MEANS NECESSARY. You probably can't tear up much, the damage is done. Drive the pistons out with a block of wood, that way it won't mess up the cylinder. The piston is probably already ruined so it won't matter.

 

What do you mean by "drive the pistons out with a block of wood"? Do you mean by pushing? I tried to push the piston back down, but it wouldn't move. I'll take apart the left side (seems to be OK...well almost OK), and see what I can do with the right...
what a mess!

 

What he means by a block of wood is to put a short 2x4 on top of the piston and hit it with a hammer. before you do this soak the piston walls with some type of pentatraing oil and maybe it might some out easier. Try not to get and pieces into the crank if there are not anything in there already. You will be lucky if you don't have to buy a new cylinder. The min that you will have to do is get it recoated. If the block of wood does not work, use a piece of pipe and a bigger hammer.

 

hehe..by the sound of it, you've really screwed up your Rotax motor. Those genuine rotax parts arent cheap!!
What I do when somethings blown up is get a nice block of wood....tap on the piston thats at tdc till it budges, then squirt a ton of marvels mystery oil in it to get things moving.
Good luck

 

Thanks. I made it....I admit this was more of a desperation post (sooo sorry to sieze the sled while snow is falling!!!).
Anyways. The left side, I could pull it out (the piston was at the lowest point), so I couls play with the crank to pull the right piston out (separate cylinders). The wood became helpful to get it out at the end...even with 1 inch inside, I couldn't take it out....
For the curious ones, I'll have to change my pistons/rings...and rechrome the cylinder, maybe rebore (I'll have to clean off the aluminium deposits before). Rods, crank are OK.

Thanks for the replies

 

Drive it with as big of a hammer as necessary. I don't mean destroy your engine, just use what ever force needed to remove it.

 

I am glad it didn't ruin everything!

 

For once I can't bash your ride...I own a Bombardier MXZ too!

Good luck and hurry up so we don't miss the snow!!

Brian LOL

 

Wack the side of the cylinder with a rubber mallett, chances are its the little nubs on the bottom of the cylinder that are making it stick not the piston itself (though it could be) but probally not, Id stay away from hitting the piston itself unless you want to do a little bottom end damage..