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Engine alignment

SVTSINR

Jet Boat Lover
Messages
34
Reaction score
17
Points
72
Location
White Lake, MI
Boat Make
Scarab
Year
2014
Boat Model
Impulse
Boat Length
19
Long story short I sucked up a couple of rocks and trying to use reverse to get them out I sucked up the tow rope. My dealer wouldn't be able to look at it until September so I decided to dig in. I replaced the impeller and wear ring which fixed any cavitation I had but I noticed a vibration above 5k rpms. All this talk of carbon seal had me thinking plus I read on the seadoo forums of a engine alignment vibrations.

Want to say thanks to Ron @scarab for getting the carbon seal part numbers and told me not to order the China knock off shit off of ebay. The job is pretty big and not worth saving $75 in parts.

0460209 Bellow $23.79
0460208 Carbone Ring $83.09
0460210 Support Ring $51.59
0460335 O-rings Qty 2 $2.08 each
 
The carbon seal had some scratches on the face but I have no idea what is normal. Some marks on the support ring, almost like hot spots on a flywheel.

I honestly thought the carbon seal rode on the driveshaft but it doesn't even make contact, only the support ring.
 

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Since everything is apart I figured I should check engine alignment. I ordered the SBT tool for a Seadoo and this is where I'm stuck.

The engine is way off, too high in the front and leaning towards port. I assume I can remove shims from the front mount and add shims to port to center the engine. Any idea where to get shims? The ones on SBT website look different.

Has anyone tried this?
 

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I would like someone to explain to me this giant patch of bondo that they felt didn't need painting?
 

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Have you checked your engine mounts? Are they all solid....try rocking motor by hand.

What makes you think the motor is out of alignment? Does the shaft line up?
 
Have you checked your engine mounts? Are they all solid....try rocking motor by hand.

What makes you think the motor is out of alignment? Does the shaft line up?

Only 80 hrs on the boat so pretty solid.

Shaft is a good 1/8-3/16" off.
 

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Great work @SVTSINR ! To align the engine, you need to shim the engine mounts. But also make sure your engine mounts are in good shape. They are prone to crack.
 
Your floating ring supports your observation that the engine is out of alignment. It should be very smooth all across its face.

It also looks a bit dark on the edge. It's very important to not run it dry except for a brief time for flushing (you may already know this, if so, i apologize)

Good luck on the alignment.
 
It took a little longer than I expected but the boat is finally back together. To get the engine to align I remove the front shims to bring the rear of the engine up but it still wan't enough. Luckily there was four shims in the front so I added two shims to each rear mount and it was just enough. There is quite a bit of slop in the engine mounts to allow for side to side adjustment. Once I got the engine at the same angle as the alignment tool I then wiggled the engine into position, good thing these motors are light. Once the alignment shaft was in the pilot I then tightened the engine mounts. There is still probably some slight binding in the tool but it's a 100% better than before.

Just some notes to consider:

1. I believe the motor shifted when I sucked up the tow rope causing the misalignment and vibration above 5K. Sucking up a rope is so easy to do that I can't imagine waiting for my dealer to fix my boat every time. Understanding the engine alignment and carbon seal is a must have for these boats. I'm not talking about watching a youtube video either, look at your boat.

2. It took me roughly 15 hours but I could probably do it in 6 now. I jumped in and out of the boat about a 100 times trying to get the right tools or setting up the alignment tool.

3. It's a two person job, you need someone to slide the driveshaft from the rear of the boat. You also need someone to hold the screws from the bottom of the boat on the protective sleeve on the driveshaft, this step is not necessary if you are just doing the carbon seal but I highly recommend performing the alignment. (the sleeve hits the alignment tool)

4. Lay a pad on top of the engine, my chest is all bruised from laying on top of the engine for 15 hours. That dipstick is killer...

For the record I've never ran my boat dry except for winter flushing for no more than two minutes. I think the process is contradictory, you need to flush the boat running but can't do it for more than a minute, just doesn't make sense. I'll replace the $80 seal over cracked engine components any day.
 

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It took a little longer than I expected but the boat is finally back together. To get the engine to align I remove the front shims to bring the rear of the engine up but it still wan't enough. Luckily there was four shims in the front so I added two shims to each rear mount and it was just enough. There is quite a bit of slop in the engine mounts to allow for side to side adjustment. Once I got the engine at the same angle as the alignment tool I then wiggled the engine into position, good thing these motors are light. Once the alignment shaft was in the pilot I then tightened the engine mounts. There is still probably some slight binding in the tool but it's a 100% better than before.

Just some notes to consider:

1. I believe the motor shifted when I sucked up the tow rope causing the misalignment and vibration above 5K. Sucking up a rope is so easy to do that I can't imagine waiting for my dealer to fix my boat every time. Understanding the engine alignment and carbon seal is a must have for these boats. I'm not talking about watching a youtube video either, look at your boat.

2. It took me roughly 15 hours but I could probably do it in 6 now. I jumped in and out of the boat about a 100 times trying to get the right tools or setting up the alignment tool.

3. It's a two person job, you need someone to slide the driveshaft from the rear of the boat. You also need someone to hold the screws from the bottom of the boat on the protective sleeve on the driveshaft, this step is not necessary if you are just doing the carbon seal but I highly recommend performing the alignment. (the sleeve hits the alignment tool)

4. Lay a pad on top of the engine, my chest is all bruised from laying on top of the engine for 15 hours. That dipstick is killer...

For the record I've never ran my boat dry except for winter flushing for no more than two minutes. I think the process is contradictory, you need to flush the boat running but can't do it for more than a minute, just doesn't make sense. I'll replace the $80 seal over cracked engine components any day.
I think everyone on this forum should take a moment to thank @SVTSINR for all he has done. You've done all we've wanted to do but been too scared. You really are the real MVP and thanks again. And a big thanks to @ScarabMike too. You have helped us so much and you didn't even have to. You 2 guys are great I wish we all lived near one another.
 
I would like someone to explain to me this giant patch of bondo that they felt didn't need painting?
I know you posted this about the Bondo last year but I thought I'd respond to you. . I just recently took my grate off and noticed gelcoat missing and cracked , looks like Scarab let's the boats go out from the factory like this!! It is now in service for repair of this area! This is unacceptable poor quality workmanship.
 

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Weird, with your boat being 3 years newer I would assumed the issue would be corrected.

Taking that grate off is a ridiculous process in itself, good thing my son is old enough to hold a wrench.
 
Weird, with your boat being 3 years newer I would assumed the issue would be corrected.

Taking that grate off is a ridiculous process in itself, good thing my son is old enough to hold a wrench.
I had a lot of corrosion on the aluminum took it apart to get it repainted that's when I noticed gelcoat missing!! They sold this boat with spec. out at 44mpr ,I usually just get 40!!! so speed increase would be nice! Zinc anodes doesn't work well here in a freshwater
 
It took a little longer than I expected but the boat is finally back together. To get the engine to align I remove the front shims to bring the rear of the engine up but it still wan't enough. Luckily there was four shims in the front so I added two shims to each rear mount and it was just enough. There is quite a bit of slop in the engine mounts to allow for side to side adjustment. Once I got the engine at the same angle as the alignment tool I then wiggled the engine into position, good thing these motors are light. Once the alignment shaft was in the pilot I then tightened the engine mounts. There is still probably some slight binding in the tool but it's a 100% better than before.

Just some notes to consider:

1. I believe the motor shifted when I sucked up the tow rope causing the misalignment and vibration above 5K. Sucking up a rope is so easy to do that I can't imagine waiting for my dealer to fix my boat every time. Understanding the engine alignment and carbon seal is a must have for these boats. I'm not talking about watching a youtube video either, look at your boat.

2. It took me roughly 15 hours but I could probably do it in 6 now. I jumped in and out of the boat about a 100 times trying to get the right tools or setting up the alignment tool.

3. It's a two person job, you need someone to slide the driveshaft from the rear of the boat. You also need someone to hold the screws from the bottom of the boat on the protective sleeve on the driveshaft, this step is not necessary if you are just doing the carbon seal but I highly recommend performing the alignment. (the sleeve hits the alignment tool)

4. Lay a pad on top of the engine, my chest is all bruised from laying on top of the engine for 15 hours. That dipstick is killer...

For the record I've never ran my boat dry except for winter flushing for no more than two minutes. I think the process is contradictory, you need to flush the boat running but can't do it for more than a minute, just doesn't make sense. I'll replace the $80 seal over cracked engine components any day.

@SVTSINR Hope you are still around and well. Question: did you remove your catalyst so that you could get to the drive shaft and carbon seal easier?

I decided to take the job on myself as well, changing out the carbon seal. It does not appear too complicated. Just wondering if I would make it easier on myself to remove the catalyst? What was your experience?
Thanks
 
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