Going through crankcase - questions

[andy.262]

So I'm taking apart the engine down to the crank, as recommended on this forum after my RAVE valves and pistons blew apart and got chunks of metal all in there. I have a few questions now that I'm in the process of actually taking it apart.

1. Will I need new outer crank seals? I'm thinking even if I don't need them I should probably just replace them anyways while I'm in there...
2. There's an old SBT video of a tech taking off the PTO flywheel with a chain wrench. Is that really the best way to do it? The flywheel looks kind of thin to be able to fit a chain wrench around, but it might be possible.
3. Once I get the crankcase split, how do I "clean it out"? I'm assuming I shouldn't use water, so maybe carb cleaner? 2-stroke oil?
4. For the mag flywheel, I've gotten this far before realizing I need the special puller to actually get it off. Once I get the puller, does it matter the orientation of the wheel relative to the crankshaft? This is related to the timing, yes?



This is the 787 engine out of a 97 SPX, if that helps. I assume it's very similar for most of these engine though.

 

[mikidymac]

The flywheel is keyed to the crank so you can’t put it on wrong.

Chain wrench and heat is the best to remove the rear PTO.

Yes you need new crank seals and OEM are the best. You will need ThreeBond 1184 sealant too.

Gasoline is the best thing to clean the cases and crankshaft. Just lube the crank bearings with fresh 2 stroke oil.

 

[andy.262]

Awesome, thanks! Where do you get OEM crank seals from? I'm having a hard time finding ones that actually specify that they are OEM

Also, the ThreeBond is for between the crankcase halves? I already have some Permatex Ultra Black, will that work as well, or maybe another Permatex product? Permatex is the most available brand around here, but I could order ThreeBond if there's a strong reason to

 

[mikidymac]

DO not use any RTV sealant.
You can use Permatex MotoSeal, it is the same as 1184.

Any seadoo dealer or even in the upper right of this screen under "Seadoo Warehouse" can supply the OEM seals.

 

[andy.262]

so I'm looking for #7 on the first diagram, and #1 on the second diagram, correct? The mag-side seal comes off with the mag housing?

 

[biggiescott]

The flywheel is keyed to the crank so you can’t put it on wrong.

Chain wrench and heat is the best to remove the rear PTO.

Yes you need new crank seals and OEM are the best. You will need ThreeBond 1184 sealant too.

Gasoline is the best thing to clean the cases and crankshaft. Just lube the crank bearings with fresh 2 stroke oil.

I used parts cleaner to clean my block not as dangerous as gasoline just my opinion

 

[mikidymac]

Yes, that is correct.

 

[mikidymac]

I used parts cleaner to clean my block not as dangerous as gasoline just my opinion

Correct, gasoline is not safe so use at your own risk. But it doesn't leave any residue unlike solvent.

 

[andy.262]

Gasoline worked incredibly well to clean it out, thanks for the tip there!

While I was disassembling, I noticed that this seal on the counter balance shaft is shot, yes?
Is it possible to replace this? Maybe I'm better off just getting a good condition used counter balance shaft?

 

[DanSquires]

Gasoline worked incredibly well to clean it out, thanks for the tip there!

While I was disassembling, I noticed that this seal on the counter balance shaft is shot, yes?
Is it possible to replace this? Maybe I'm better off just getting a good condition used counter balance shaft?


View attachment 47327

I rebuild those, 85 bucks.
New bearings and seals

 

[mikidymac]

If you have a press they are pretty easy to do yourself.
Yes the seal needs to be replaced so you might aw well do bearings also.

 

[andy.262]

Thanks for the quick replies! I think one of my relatives has a press I might be able to use. I'll have to add a press to my tools wishlist, I was just recently in another situation where it would have been helpful

 

[mikidymac]

The Harbor Freight 20 ton press is one of the best tools I have bought. Get it on salw and add the 20% off coupon.

 

[GGuillot]

There's an old SBT video of a tech taking off the PTO flywheel with a chain wrench. Is that really the best way to do it? The flywheel looks kind of thin to be able to fit a chain wrench around, but it might be possible.

Ask yourself if you really need to remove the PTO flywheel before you do so, people have twisted cranks because of the force needed. If the bearings sound like roller skates and aren't smooth it may be time anyway.

That SBT video is a joke, the PTO flywheel is on there very very very tight as in 110 hp has torqued it on for you. My experience removing 2 of them, you need a shit ton of leverage. If you can rent or get a hold of a chain wrench to grab it and get the leverage on it go for it. But...I had to use an impact hardened impeller tool with a HD sliding 3/4" breaker bar and impact socket....with a 5-6 foot cheater pipe. Big 1000 ft pound impact guns won't work either, plus you could tear splines up going that route. The challenge is having something to hold the engine or crankshaft, I've seen people jack their truck up and lower it down on the engine to hold it. I went to a place that had a massive floor vice to hold the crank. A couple people observing me were convinced I was turning it the wrong way until it popped loose.

If you do decide to use the impeller tool, don''t even attempt with 1/2" tools, they will break, bend or you'll get a hernia.

 

[andy.262]

This was my rig to hold it in place while I used a chain wrench and a 2 foot bar (excuse my filthy engine). Basically ratchet strapped it to a plank so that the floor could keep it from spinning. A knotted piece of rope to prevent the crank from turning. The little piece of 2x4 on top is so that the metal ratchet didn't dig into the metal of the engine. This in combination with heat, and I was able to get it off without without too much trouble.



The engine is much much cleaner now, who knew there was actually white under all that crap

 

[mikidymac]

For the flywheel a chain wrench and heat while it’s still bolted in the ski is the easiest way.

Get it hot then with tension on the wrench smack the wrench hard and two or three swings the will pop off. The shock does more than constant pressure.

 

[biggiescott]

I removed mine on the bench I made a motor mount and mounted it to my work bench. Then I used a board to stop the motor from spinning however a rag under the piston would have worked had my jugs still been installed

 

[andy.262]

So, putting the crankcase halves back together, the manual says to put Loctite 515 (Permatex Motoseal in my case) on the screw threads for the bolts that hold the halves together.

If I do this, will I ever be able to get these bolts out again? Seems kind of permanent... Is there some alternative you guys would recommend, or should I follow the manual here?

 

[GGuillot]

So, putting the crankcase halves back together, the manual says to put Loctite 515 (Permatex Motoseal in my case) on the screw threads for the bolts that hold the halves together.

If I do this, will I ever be able to get these bolts out again? Seems kind of permanent... Is there some alternative you guys would recommend, or should I follow the manual here?

View attachment 47517

The 515 is fine on threads, it's nothing like the red 272 permanent stuff. Use the Motoseal or like wise Three Bond 1184 on the case halves. While you got it apart, not a bad idea to chase all the bolt holes with a tap to clean them up and get a good torque.