98 GTX seized overnight

[rbach]

I have a very perplexing problem, my GTX has a new motor in it, about 15 hours in total, 10 last year and 5 this year so far.
On the weekend we were using it and it ran fine, put it away and the next morning it was seized.
I unbolted the impeller shaft to make sure there was nothing locking up the pump.
I then put a wrench on the output shaft and was eventually able to move the engine although it is very tight, to tight for the starter to turn over.
I have no idea what would have caused this, I'm assuming that for some reason either the bottom end or top end is seized. There is plenty of oil in the tank, I have pulled the plugs and they do not look leaned out or any sign of fouling.
What should be my first step in figuring out the problem, should I try and pull the tops off the pistons to look at the cylinder walls or should the engine just be pulled out and apart.
My experience with the engines is minimal although I am very experienced as a mechanic with conventional engines.
Any insight as to possible cause and next steps would be great.
Thanks
Randy

 

[derek]

if it is still under warranty don't touch it. some builders void warranty if you remove the head. who did the engine? who did the install? get hold of them. see what they say. if it is all on you, pull the head first and check the bores. that won't be it though. pistons lose compression. they don't glue themselves to the walls. the prob is your crank, or possibly balance shaft bearings. does the oil pump work? or were you wondering why you never had to add much oil to the tank? is the reservoir for the balance shaft full of oil? a lot of people swear by pre-mixing. it is frowned upon in this forum, though.

 

[rbach]

Thanks Derek, as you will see by my answers I'm fairly new to Seadoo's.
The engine was in the machine when I acquired it from my brother, it won't be under warranty anymore I'm sure, even though the hours on it are minimal.
I was having to add oil to the tank, toped it off prior to taking it out this last trip.
I'm not sure where or what the balance shaft and balance shaft resevoir are or would be located. Can you give me some insight as to where this would be located.
I did pull the engine on the weekend, I also pulled to piston cap off, the pistons and cylinders are in great shape, you can still see some of the honing marks on the cylinder walls.
When I pulled the starter out though there was some really rusty water that came out of stator housing hole.
I haven't had a chance to pull the stator housing off yet but I'm wondering if the stator assembly could have gotten rusty enough for that to have seized up the engine.
This thing was running fine the night before I shut it off, next morning nothing.
Thanks for your reply.
Randy

 

[derek]

you may be in luck. i junked a top end because i didn't pull my rusted flywheel first. you will need to first take off the housing cover. then unbolt the big nut. 1 and 3/16ths socket worked for my 720 motor. you are sposed to use correct metric. now-get a harmonic balancer puller from the auto parts store. put washers between bolt heads and puller arms. make sure you have threads fully in the flywheel face. (make sure you have the right thread bolts) crank the puller tight. now crank it tighter. now get a propane torch and start heating the area right next to the shaft the nut threads on. it will probably pop. once it comes loose, you will still need to crank it off with the puller. now you need a flywheel and probably a stator. the flywheel is so rusted inside it will always grind on the stator. the stator likewise, plus it is unhappy that it was float tested and failed in the first place, and probly won't charge or spark. they are available on ebay. they are fairly cheap, because they don't fail that often. your starter may be ruined too. i will do a search for a thread about the balance shaft reservoir and get back to you. i need to go to work and make money to buy seadoo parts.

 

[rbach]

Thanks, I'm hoping thats what it is, your right about the charging, it hasn't been since last summer, no issue with the spark yet.
I'm going to pull the front cover off this weekend and see whats in there.
Randy

 

[rbach]

For anyone who reads this and ever has the same problem the engine was not seized. It was the starter and bendix drive causing the problem. Once these were cleaned up the engine went back in and runs fine.
Thanks to those who helped.

 

[derek]

always start with the cheap part and work up to the most expensive. especially when the cheap part has to come off anyway. that is a new one on me, though.