1995 XP Rotax (720?) Engine Seized...

[jbhouston]

Hi all, Newbie so please be gentle!

Took the ski to a local repair shop and they diagnosed a seized engine (didn't remove the head, which puzzles me but...) they said the plugs were caked in crud and likelihood of a seizure on one of the cylinders. The engine was running as late as November before being flushed & turned off.

My questions are:
- For someone who describes themselves as a novice/intermediate mechanic, on a scale of 1-10 how easy is a removal, stripdown and rebuild of this particular engine?
- If I can get the head off the engine, what's the best course of action to free up the seized cylinder? (soak in Diesel? turn by hand?)
- Has anyone came across some really good Youtube videos or step-by-step guides for a teardown and rebuild?
- I think I'll need a new gasket after taking the head off it, but is there anything else I definitely need to order for a rebuild? Is there a "rebuild kit" part number I can obtain?

It's also worth noting I'm in Scotland so any Seadoo owners with recommendations of garages and/or part suppliers are very much welcomed (even by PM/Email if it's against house rules!).

Many thanks in advance and subject to getting this thing going again I hope to become a fully paid-up member of the Seadoo club

Kindest Regards,
John H

P.S. This is used as a salt-water craft

 

[Bills86e]

I would reccommend : http://www.shopsbt.com/ You get a no-fault warranty, but you have to do the following:
Break your engine down to a shortblock and exchange it for a remanufactured one. While you are waiting, you can go thru the rest of the ski, like jetpump, clean gas tank, bilge, driveline, replace fuel lines, grease your cables, rebuild your carbs. You should exchange your RV
cover if its out of spec. All of this is in this forum and your Shop Manual.

Bills86e

 

[ltdyfz99]

It does require some skill to remove the bolts if the motor is a salt water engine, unless it was put together with anti-seize or grease. Most people try to remove the head bolts then end up snapping off most of the bolt off at the cylinders which can be removed by a machine shop if needed.

Was this engine properly stored, fogged, or was oil added to the motor to keep things from rusting up?

If you can get the head off keep going and take the cylinders off. Check the walls for pitting, if they are pitted you will need to get them bored out. Not pitted then a fresh ball hone more then likely will allow you to use the top end again if you simply put new rings, and wrist pin bearings.

You can get a repair manual and do this yourself if your handy.

If that crank spins slow you might be able to free it up, you more then likely have the rings stuck on the cylinder walls due to moisture in the water box/exhaust evaporating into your top end.

 

[jbhouston]

Thanks Bills86e & ltdyfz99... all advice is great advice

I think there's something in the "moisture" idea, as it was under canvas and we did have some pretty warm weather recently following a fair few cold snaps - it's Scotland after all! But the early signs are moisture on the spark plugs.

On the subject of the head bolts, I've had this in a car engine so I know what you're getting at... I think I might have to snap them off, but I'll give them a damn good try first and drown them in WD40 or something I'm busting to know whether it will turn by hand coz that will say a lot but I'm equally thoughful of breaking it down and seeing what's up for myself, that way I can be sure what's underneath me when I'm back out in the water...

I had a seperate issue today when bringing the trailer home... flat tyre, no spare... limped to the nearest tyre shop and left it overnight to be picked up tomorrow.

I'll get a look at it and report back on my findings to see what the thoughts are. Really appreciate you both taking time out to post some assistance however

Have a great weekend folks,

JH

It does require some skill to remove the bolts if the motor is a salt water engine, unless it was put together with anti-seize or grease. Most people try to remove the head bolts then end up snapping off most of the bolt off at the cylinders which can be removed by a machine shop if needed.

Was this engine properly stored, fogged, or was oil added to the motor to keep things from rusting up?

If you can get the head off keep going and take the cylinders off. Check the walls for pitting, if they are pitted you will need to get them bored out. Not pitted then a fresh ball hone more then likely will allow you to use the top end again if you simply put new rings, and wrist pin bearings.

You can get a repair manual and do this yourself if your handy.

If that crank spins slow you might be able to free it up, you more then likely have the rings stuck on the cylinder walls due to moisture in the water box/exhaust evaporating into your top end.

 

[jbhouston]

Also meant to say, I'm going to hunt for a Seadoo XP 1995 Owners Manual and/or Service Manual as the previous owner didn't have any docs at all I can generally follow a Haynes manual and schematics/drawings so we'll see what shape I'm in after reading one of these

 

[ltdyfz99]

start from outside in, basically the opposite of the torque pattern when the motor would be put together to properly release the torque on those bolts. Lay the engine on the side so you get the right leverage also. Def build it up, because these ski's when left sitting can torture you later on even if everything fine. Any rust will act like sand paper on the ball bearings of the crank.