Engine misaligned?

[Lothsahn]

Had my engine replaced by a shop 2 years ago and I just had my 5-7 year old carbon ring wear out after about 50 hours. Did that wear faster than expected?

Gonna tear it down but I don't have an alignment tool. Is there any way to tell from the picture if the shop didn't align my new engine properly?

 

[WaarrEagle]

If that is a picture before you took anything apart, it sure appears out of alignment. But hard to really tell with the boots on. When you remove the driveshaft to replace the carbon ring, it should be pretty obvious if it is out of alignment.

 

[Lothsahn]

Yeah, that's a picture before I've done anything.

Currently hotter than hell here and been busy. I'll tear into it in a few days when it cools off.

 

[WaarrEagle]

Some folks believe you can just reinstall the same shims/mounts from the old motor and it will be fine. When I put mine back it, there was a TON of sag and I had to buy 2 shim kits to compensate. I guess after 20 years the mounts start to compress. I wonder if the shop took the "put it back how it was" approach which led to this.

 

[POPPS]

Based on that pic,, the carbon ring is not aligned( centred)

 

[Lothsahn]

Got it apart. How does this look to people?

There are some surface scratches on the carbon ring, but I don't know if that's a problem.

 

[WaarrEagle]

Your bigger issue is finding out why it was so off center in the first place. Was the c-clip in tact when you took it apart?

 

[Lothsahn]

Yep. C clip was in place. Stainless steel hat was over it as expected. Came apart just fine, no real issues.

Visually, all the parts look fine now that they're apart.

The actual symptoms was heavy cavitation/aeration in hole shots. Once at 15 mph, it had good acceleration and top speed. Symptoms got worse the more I rode it.

Wear ring has one 1/8" deep gouge in one spot, but otherwise in good condition. Impeller looks to be in good condition.

 

[Lothsahn]

Any ideas, given the parts, why I was having severe aeration/cavitation?

 

[tobytd]

Weak bellows will allow cavitation on hard acceleration

 

[Lothsahn]

Update: It was DEFINITELY misaligned. The alignment tool was off by 1/8" from even going into the PTO with the previous setup

I bought the SBT alignment tool, removed all left and right side shims, and the engine was quite far off to the right and below the shaft

To even get it to be mostly aligned, I needed THIS stack of shims on the right side with all left shims removed.

It's still off by a little... Adding shims to the right side keeps moving the engine left and up. but if I add more shims the engine is getting too high, even though it's still slightly to the right of the driveshaft.

It's really close, but I hear a little clink as the rod goes in the PTO, and it doesn't slide easily out when I push the whole rod in.

1) How critical is it that the alignment be perfect? It's already massively better than before.

2) Is something wrong with my sea doo or engine? I've never heard of needing this many shims

3) The bolts that secure the mount to the hull aren't long enough given the number of shims I needed. Are there longer standard bolts?

4) Is there something I should be doing differently?

 

[tobytd]

Check the height of the mounts
The 2 rears should be the same size

 

[Lothsahn]

Check the height of the mounts
The 2 rears should be the same size

Both appear to be about 3CM tall (at the rubber part and they visually look the same).

Can you slide the engine left and right without shims? Maybe I just need to just try to loosen all the engine mount bolts at the same time and slide the engine mounts to the left?

 

[mikidymac]

Yes, you can maneuver the mounts.

 

[Lothsahn]

So I had the engine mount bolts out earlier, I went to put them back in, and now they screw in a little bit then suddenly get tight like they're cross threaded. I didn't want to force them, as I'd never experienced this before. When the bolt gets a fairly hard to turn, I'd say there's 1/2" left before the bolt would be snug.

Any suggestions as to how to proceed? I don't want to break my hull and be in an even worse situation. I'm rather new at this "mechanic" stuff. I certainly could use more force.

Maybe I tightened them too much with too many shims in? I tightened them some, but not too hard.
Maybe debris got in the holes and the bolt doesn't have room? The bottom of my ski has some old oil and other gunk--I never had it apart to give it a full powerwash.

Any ideas?

 

[mikidymac]

I would get a thread chaser and clean the bolts and hull inserts. Not a tap and die

 

[Lothsahn]

So with a lot of shims I can get it close.

I really don't feel comfortable with shimming the pump... I don't know how. Anyway, I bought longer 702 stainless bolts. Can I just have some extra shims in there?

Also, how do you know how many shims you need for the front engine mount? The alignment tool goes all the way in but binds a little, and I can't tell how I need to shim the front... Whether up or down.

 

[mikidymac]

Trial and error. We can't tell you, just go until the alignment tool goes in easily.

 

[Lothsahn]

Trial and error. We can't tell you, just go until the alignment tool goes in easily.

Fiddled with it more. The tool goes in and clinks when it hits the back. But it doesn't come out easily... It sticks when pulling it out.

Given the driveshaft is splined, is this close enough? It appears the engine is actually horizontally twisted slightly compared to the plate. When I twist it to the left it binds hard, and when I twist it right it gets much better. But there's not enough slop in the mount bolts of the front engine mount for me to twist it till it slides in easily.

I don't see how I could make it better without shimming the pump.

 

[WaarrEagle]

My unprofessional opinion from doing my own SeaDoo with a similar stack of shims... you are close enough. I was similarly shocked how many shims were needed. Only thing I can figure is those mounts must really sag/compress over time.

 

[Lothsahn]

Well, I got it all done. Ski assembled, working, put in water, and MAN, it's great. No more rattle at idle, no aeration during hole shots. Just runs the way a jet ski is supposed to! It's like a brand new ski, 30 years later.

I noticed the PTO plate gets hot (~150F) during operation. Is it normal for it to get that hot?

For those who followed this saga (or come later with similar symptoms)...

Things that were wrong on my ski after the shop replaced the engine:

• Fuel line hose clamps were all loose (leaking fuel)
• Bolts holding on the air intake plate to the hull were over tightened and are stripped.
• Choke cable was just dangling loose in the carburetor mount. Nut was just hanging on the cable--never screwed in at all or no loctite
• Driveshaft was missing the PTO bumper entirely (causing idle rattle)
• Engine was badly misaligned--off by 1/2 to 3/4"
• Oil line at the Oil pump had a zip tie not even over the fitting. The mechanic just randomly put a zip time in the middle of the oil line? He also left a long tail on the zip tie to get caught up in the oil pump throttle mechanism.
• Oil pump throttle cable was frayed (only the outer sheath--the inner sheath was fine)
• Driveshaft bellows was way too soft (this was my fault--I bought an aftermarket part a few years ago)
• Rubber PTO boot split and failed, slinging grease all over the bottom of my ski
• Carbon ring wasn't even close to lined up with the stainless steel hat. It's better now, but still not perfect.

Despite all that, I put 25 hours on the ski with no apparent issues until the carbon ring caused a loss of performance. I am *never* taking my ski back to that shop again.

If others have poor hole shot performance, I believe the weak bellows were the primary cause of my aeration and loss of performance.

 

[mikidymac]

Yes, the PTO gets hot.