Serious Engine Troubles on 94 SPX

[randomguy]

Hey everyone:

So I finally got around to trying to get my boat going. Bought it in July last year, ran it pretty well all last year. Winterized it per the "standard" stuff touted around here.

Last week I got it out, charged the battery up and tried to start it. I got just enough smoke and activity to think "wow, it's gonna...." and then nothing. Then just clicks. So I take off the counterbalancer shroud so I could watch it turn. The starter is trying but not getting the job done. I *cannot* roll it over by hand either.

I tear into it and get the starter out just to check it out. Ran it offline and it's working great. So I put a ratchet on the flywheel nut and try to roll it back the other way. With just a little bit of fight, I get it worked loose, get half a turn and hit something hard.

So basically, I can get a half turn by hand and no more. I've got a lot of "theoretical knowledge" about engines, but not a ton of practical experience. I'd like to pull off the drive shaft to the jet pump just know for certain whether I've got engine problems or propulsion system problems, but I'm a little squeamish about tearing that system totally apart.

Any other suggestions about possible solutions? I'm pretty baffled since I ran it right up on to the trailer in September and really didn't touch it until now.

Also, I have not yet established a shop that I trust, so if or when I need to take it somewhere, I'm starting from the ground up. I bought this unit used privately, so I'm still pretty fresh into the PWC world..... Any and all suggestions are very welcome.

Thanks!

 

[Dr Honda]

Take the pump out to make sure it's not frozen... but you are describing something that fell down into the rotary valve, and is jamming the engine.

 

[randomguy]

Take the pump out to make sure it's not frozen... but you are describing something that fell down into the rotary valve, and is jamming the engine.

Not to sound too stupid when I ask this, but do I just start disassembling from the rear and work my way forward? Looking at the SeaDoo manual I downloaded, they make it seem extraordinarily compliacated just to get the drive shaft uncoupled from the engine. Pointers?

Thanks!

 

[Dr Honda]

It's not a big deal since you have the old style seal.

1) Remove the water feed hose from inside the transom.
2) Remove the steering cable at the pump nozzle. (a single 6mm bolt)
3) remove the 4 nuts that hold the pump to the hull
4) Pull. (it should come off if it isn't rusted up, or glued to the hull from an old owner)

Driveshaft:

1) With the pump out of the way... it should just slide out of the engine.

Easy.



With that all out of the way... you will be able to tell if the engine is the issue or not.

 

[randomguy]

Wow, thanks for the great post. Doesn't sound too bad. I do know that the exterior pump housing has been glued to the hull because I've seen some black silicon-ish seepage that must have came out when it was last assembled.

Not sure how much of a pain it'll be to remove until I unbolt and actually try to dismount it.

I don't have a mental picture of the water feed hose you're talking about, but I'm sure it'll make sense when I'm standing over the hull tonight.

Thanks again!

It's not a big deal since you have the old style seal.

1) Remove the water feed hose from inside the transom.
2) Remove the steering cable at the pump nozzle. (a single 6mm bolt)
3) remove the 4 nuts that hold the pump to the hull
4) Pull. (it should come off if it isn't rusted up, or glued to the hull from an old owner)

Driveshaft:

1) With the pump out of the way... it should just slide out of the engine.

Easy.



With that all out of the way... you will be able to tell if the engine is the issue or not.

 

[randomguy]

Well I got the prop and the drive shaft out. The bad news is the the problem is still there. Not sure what my next move is.

 

[Dr Honda]

Well... if you are getting a half turn out of the engine... there is either damage to the rotary valve, or the rings broke on one jug.

Regardless... it's time for the engine to come out.

 

[randomguy]

Well I took the cover and the head off. The heads of the pistons are pretty carbony and there was some gunk inside the cylinder in the corner pockets by the bolts that hold the cylinders onto the crankcase. But I didn't find any smoking guns. From the top, the rings look pretty normal. The rear piston almost makes it all the way down so I can see down into the cavities on the intake side. But the front one gets hung up and doesn't get that far down.

So I was tempted to pull crack the bolts and lift the cylinders off from the top side. But in the end, I didn't really want to let the rings out of the cylinders. So I guess I'll pull the engine so I can turn it upside down and take the bottom half off. I need to get some hose pinchers so I can close off the lines.

A couple questions I have:

1. How much does this thing weigh? I don't have a puller, but I could probably borrow one if I need it. Would I just be able to lift this thing out?
2. Let's just pretend for now that this will be something easy and I'll just be able to remove whatever the obstruction is and re-assemble. What parts should I replace while I have the engine out? Specifically, I'm thinking especially of seals. I'm hoping to leave the bearings and stuff on the crankshaft undisturbed. Is this realistic?

I did actually speak to a guy at a shop today that works on these things and he pretty much told me that they don't usually rebuild these engines because it's not cost effective. He said he'd be happy to look at it for me, but for the small amount of $ I've got in this boat and it's value, this thing may be a dead soldier. So obviously, I don't really want to crack joints that would *require* money to be spent to reassemble. Know what I mean?

And again, Dr Honda, I can't thank you enough for the info you've provided. I've been on your end in a lot of guitar mod forums and when you're helping someone else, it's just no big thing, ya know. But you've given me a lot of confidence to keep going on my own and I'm still able to think positive about the outcome. Thanks a bunch man!

 

[Dr Honda]

OK... if the tops of the pistons look OK..... did you get the carbs off and look into the manifold? My original hunch was that something is blocking the rotary valve.

Before you pull the engine... get the carbs off, and see if anything dropped into the engine.

To your questions:

1) A full engine without the carbs, and pipe is about 75 Lbs. So... depending on how strong you are... it is possible to get the engine out by yourself (or with a helper) without a lift.

2) Without specialized tools... it is not possible to replace the crank seals and bearings at home.


the guy at the shop is right. Unless you want a race engine... it's not worth paying the labor to have the shop do a rebuild. An SBT engine is the cheapest way out... and you can get a 2 year, no fault warranty on it.

 

[randomguy]

Can the carb even be removed while in the hull? Almost looks like the carbs were subassembled to intake manifold and the valve plate before being put on. Can't get a wrench on the nuts that hold the carbs onto the studs in the manifold because the engines in the way. Am I wrong? Thx!

 

[randomguy]

Well I got the engine pulled out last night. There's a very small oil line that was broken below the carb and was likely shooting oil all over the place. I'm hoping that this hasn't caused my engine to be seized based on lack of oil, but at the end of last season, I ran it right up on the trailer....

So on to next steps. I'll have to remove the flywheel and flywheel housing in order to open the bottom of the crankcase. Any secret tips on how to accomplish this without the spline tool that they show in the manual? Thx!

 

[wabbit1211]

I'd check your rotery valve behind the intake before I took the fly wheel off and tried to open the crank case< unless your a machineshop with proper too you not goning to do anything with a crankshaft anyway. If nothing is prevent the rotery vale from turning the you might want to seperat the cylinders from the block and check isomething came loose like a rod or apart some how got into the crank case. If you need a good used engine for it I have about 50 of them.

 

[randomguy]

Thanks, yeah that is actually my plan (taking off the valve first) to see.

I do actually work at a machine shop as well, but we really don't work on engines. I do have access to a water jet though, and if the mag flywheel has to come off, I think I'll cut an arm that will use the tapped holes in the FW and has a hole through the center to let my ratchet get through to break the nut.

What do you normally ask for these engines?

I'd check your rotery valve behind the intake before I took the fly wheel off and tried to open the crank case< unless your a machineshop with proper too you not goning to do anything with a crankshaft anyway. If nothing is prevent the rotery vale from turning the you might want to seperat the cylinders from the block and check isomething came loose like a rod or apart some how got into the crank case. If you need a good used engine for it I have about 50 of them.

 

[wabbit1211]

I have a bunch that are just average engines with 150 lbs compression and no unusal noise in th bottom end, any that do pass my test get parted out. These What I call average engines I sell for $ 500. I have a seadoo boat with 2 pristine 657X very low hour engine, the boat was stolen stripped and recovered when it was just months old, and sat every since the only parts not recovered were the electronics. I did hook up each engine to the electrical box off one of my xp so I could hear each one run and checked compression. which was really high. These two engines I have been asking $650 for but will come down to$600 now, but don't really care if they sell. I will leave stators and fly wheels but no carbs or exhaust with the engines. Last one I shiped was about $100 shipping and crating added to the cost. But hey come to Texas an pick it up count it as a vacation.

 

[deepdiver]

I'm still curious as to what you found behind the intake manifold re Rotax valves.

 

[randomguy]

I really didn't find anything to be honest. With the exception of the badly bent rod, the engine looks pretty clean. I didn't find any debris or anything and the plate and valve faces look pretty good.

I'm assuming that it got hydro locked with fluid above the rings, but I really haven't come up with a plausible scenario of events that I think is what happened...... That's still a mystery.

 

[deepdiver]

Thanks. I hadn't seen about the bent rod. Very interesting. Seems to have occurred when starting up after winter. Wish we knew what caused it. When I got mine, after they sat for three years, the piston was loaded up with oil and sorta locked up. I turned the shaft with a pipe wrench, took out the plugs, and blew a whole bunch of oil out. Good luck with used engine if that's the way you go.

 

[brock1]

uuuuhhhh i would say its the bent rod not being able to turn in the crank.

 

[randomguy]

Yeah I've already got the crank out and the engine is totally torn down. One rod is bent and I've just found a small crack on the lower side of the wrist pin hole on that piston. I didn't see a bunch of fluid in the chamber or in the crankcase, but obviously that piston was locked up. I don't really think it was water because I didn't find it anywhere, same with fuel. So I guess possibly the fogging oil I used got gummed up in there over the winter time and seized up the rings......

At this point, I'm doing cost comparisons of rebuilding it versus just getting an SBT rebuilt (or someone else's) engine. I'd like to do it just for the experience and the bragging rights, but in the end the deal's gotta walk the walk. Not sure what I'm going to do yet.