787 RFI - rebuild advice, tips, and suggestions wanted

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Apeman

Apeman

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The 98 GTX I bought last month, with the non-running 787RFI needs a rebuild.
Pulled the engine, and when I removed the flywheel cover, about a half quart of oil poured out. The crankcase is still half full. I think I found pieces of the mag crank seal in the oil.
So, new crank, top end, etc., will be ordered soon.
Looking for any tips, or advice from you guys that have been here and done this.
The case looks whole, no cracks or holes so far. Crank turns freely, cylinder walls look good so far.
Head was not pitted, just black.
Waiting for the proper flywheel puller before I go any further.
Did all that oil soaking the stator for 2+ years hurt it at all? It looks fine, but a 2 year oil bath is an awfully long soak.
Thank you all in advance!
-az-
 
PS, Did a full rebuild on a 587 over the winter, and it running great.
I'm hoping the 787 isn't too much tougher than the 587.
 
If you find the stator is damaged, I have a complete stator/cover/oil pump that came off a 99, should be the same.

I believe there are way's to test the stator on the bench, but in my experience they are pretty resilient little buggers.
 
The rear bearing and counterweight have to be pressed off to change the seals so new bearings are a must.
 
Crap, that's no damn fun at all. I have a shop press, but very little experience with such procedures, which is why I was planning on buying new. The budget is getting hit hard....
 
Replacing the bearings on the CB is not that bad. Just mark the location of the bearings. Did my first rebuild on a 98 RFI...just read the manual and ask :).
 
I'll get you links tonight to the skf bearings. You can rebuild the shaft less seal for under $25 and the bearings are the OEM brand.

Sent from my SGH-T889 using Tapatalk
 
Thanks mucho! Where do I get that CB oil seal?
BTW, opened up the case tonight. Mag seal was blown to smithereens. PTO seal was leaking. Can't tell if the inner seals were leaking or not, but they seemed to fit loosely in their seats. The CB dry side chamber was dry. so the oil seal must have been working. The Mag side CB bearing turns smooth and silent, but the PTO side turns OK, but it's noisy. The races are probably rusted. The Cylinders look OK I think. Taking to the shop tomorrow to have those guys check them. Hopefully they'll only need to be honed. The pistons have some scoring, and will be replaced. Deciding whether to go with a new WSM crank, or a rebuilt.
 
If the cb seals (2 back to back) are not ragged out looking and look like new just re-use those. Post a pic if you can

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Will do, tonight.
BTW, the filler cap for the Counterbalance chamber does not want to loosen. It's plastic or nylon, and if I lean on it any harder than I already have, I'm going to mangle it. Can one just put an ounce of 10-30 oil in the chamber when closing the case? Or, is there a replacement plug out there to be purchased if (when) I destroy this one?
 
You can buy the plug at the dealer of after you assemble the cases you can fill it through a small hole. I can get you a pic later. The plug is only a few bucks at the dealer.

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Since you are this far into it I would not reuse the balancer seals. Why stop short when you are this far in and they are cheap from the dealer. I think I have some WSM ones I didn't use I would send you for free. They looked a little "plastickie" so I bought OEM ones.

For the crank I have been getting OEM ones for not much more than SBT but either would be fine. The WSM ones are not bad either. IF it were my ski and I knew I was going to keep it for years and run it hard I would only use OEM. If I wanted to go cheap to sell or just not keep for a season or more I would go SBT or WSM. Just makes me sleep better at night.

Contact hfgreg for WSM parts his prices and customer service are great.
[MENTION=2]hfgreg[/MENTION]
 
Regarding OEM Cranks, new or rebuilt? And if new, where would I get one? Our (used to be) local dealer doesn't do Sea Doo anymore. Nearest place is hours away.
 
You can't buy new cranks from seadoo but you can get reman cranks form them using all OEM parts. I buy mine from Pro Caliber.com with free shipping. Ask for Ben J.
 
Crank has: Rust on counterweight lobes, but only light surface rust. The rest seems OK, but as this engine sat for two+ years, hydrolocked with oil and some small amounts of water, I don't trust the bearings, or the inner seals. The PTO bearing feels like it's chattering a little when I spin it.
I have a complete rebuild kit coming. New WSM crank. Also the cylinders were worn enough that the machine shop recommended going to the 1st (only) oversize. Do I need to mess with the Rave valve at all? I'm hoping not.
I'm gonna try pressing those CB bearings off and installing a new pair. Those CB seals feel great, and seem to be hugging the shaft like they should be.
One Question: When I rebuilt the 587 last winter, the rebuild instructions suggested a small bead of Yamabond around the outside lip/seat of the inner crank oil seals. Should the same be done with the 787?
 
Look in my Clapped out thread or my 95 XP limited thread and you will see the threebond and where I put it.

I use a 2 jaw puller on the bearings on the CB shaft. The I use the press to put them back on.
 
And, by the way, your work is above top-shelf! Very envious talents you have there. Great attention to detail.

It did not look like you ran any Threebond along the outer edge (or in the seat slots) of the inner crank seals, as was recommended for the 587 I rebuilt. Not a good idea?
 
I never have, the factory never did on a 787. I know SBT puts enough around the crank seals to choke a horse, I don't subscribe to that. I never got that, that is under an interference fit. If it's gonna leak it's gonna leak around the shaft.

Sent from my SGH-T889 using Tapatalk
 
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