Flywheel Explosion AKA Stator Help (FKA :First seized then no Spark?!?)
 

Ok...so I had my 98 sportsman 500 out this weekend, it ran great all day yesterday, then when I go to start it this morning the starter just makes a slam noise...go to pull the pull start, won't budge...the engine feels seized. Messed with it for a while trying to get it to break loose, but nothing. Finally pack it up, get it home, try a couple more times with the starter, 3rd try it seems to break free, then seems to be turning over freely. I put a new spark plug in it because I broke the old one in half using the stupid tool kit wrench, and attemp to start it. It cranks and cranks but won't fire. I pull the plug out, grounded it on the side of the head, cranked, but could see no spark. Any ideas??? It seems to coincidental that this "seized" condition and no spark happen at the exact same time.

First seized then no Spark?!?
 

B4 you even worry about spark I would do a compression test. If that ckecks out then pull the valve cover and make sure the cam and cam chain is turning.

First seized then no Spark?!?
 

Speeddrive1-If the cam isn't turning or if it jumped a tooth the compression test won't be good.

First seized then no Spark?!?
 

Just trying to do the process of elimination. Make sure everything is turning and that it has comp. I have a hard time with the fact that it was running and then sat for a while and was siezed. A motor doesn't seize up over night unless it possibly has a head gasket failure or some kind of water leak into the cylinder and causes the rings to rust to the walls.

First seized then no Spark?!?
 

That's exactly what I don't get, how it seized up over night. I'm gonna run a compression test on it tomorrow, but it definately still has some compression, the pull start feels the same and air puffs out of the exhaust, so it's not like something broke (cam chain) and there is zero compression. The no spark thing is what is really baffling me right now, how that would instantly happen at the same time.

First seized then no Spark?!?
 

Is it possible that a magnet came loose on the flywheel? Maybe after a few tries, it or the stator broke and everything started turning again. That would explain the no spark condition. Just a thought.

First seized then no Spark?!?
 

<div class="FTQUOTE"><begin quote>That's exactly what I don't get, how it seized up over night.</end quote></div>
Happens all the time.
Most of the time a stuck float will fill the cylinder up with fuel and when you try to turn the engine over it will hydro-lock.
The second thing that can happen is a blown gasket will fill the engine up with coolant and do the same as above.

Pull the dip stick and see what is on it. Is it over filled and smell fuelly? That would be the first problem. If not, drain a little oil out of the sump. Does coolant drain first. If it dose it's the second problem.

First seized then no Spark?!?
 

The oil and coolant both look fine....after a compression test I'm going to start by pulling the stator cover off and see how things look in there....that's about the only spot that I could think of that might affect both the engine being able to turn over and spark

First seized then no Spark?!?
 

Do I get a cookie if I'm right?[img]i/expressions/face-icon-small-wink.gif[/img]

First seized then no Spark?!?
 

the flywheel key may be sheared as well