98 Speedster w/787's...Starbord engine issues

[rtoth]

Hello all,

Have a question about my first sea-doo boat. Since buying it, I've had intermittant issues starting the startboard engine....Would always be able to get it going eventually by swapping plugs, and retrying. Issue seemed to be getting worse lately to the point where putting new plugs in wouldn't help...I initially suspected carb/fuel related issues, but yesterday after spending an hour fishing with my daughter, I couldn't restart the problematic engine and found there to be no spark whatsoever. After 2 attempts to start the motor, the engine would not turn over at all. I limped back to dock on the one motor, and brought the boat home for diagnosis. Starter relay tested out fine, and in going to the starter motor, found the ground terminal to be spinning loosely from within the starter(Unable to be tightened from the nut)....So I assumed that I had a starter motor issue. My brother came over and pulled the starter motor, and to our surprise, it was full/saturated with oil....Which leads me to believe I have a bad crank seal on the mag side.
Does anyone know if this can be changed with the motor in place? Do you also think a blown seal could be the cause of my initial starting issues, being that the crankcase needs to be pressurized?

Thanks,

Rob

 

[wildone72]

Can not believe the guru's have not answered this one yet. Pm Dr. Honda he knows his stuff.

 

[Armee_1]

I just rebuilt my entire star-board engine a week ago, and yes you can replace the mag seal without pulling the engine and splitting the case. The hard part will be pulling the ring gear. I had to buy the puller tool (only $18) to get it off. However, there shouldn't be a lot of oil at that seal. You said that the starter was full of oil. To me, that says your inner crank seal is leaking as well. Did that engine smoke a lot on first start up?
As far as the seal being the problem, if the engine was getting harder and harder to start, you might have slowly been losing compression the more you ran it and have toasted your mag Cylinder. I would at least pull the head cover and check for damage. Also, depending on how old that engine is (10+ years) you will want to rebuild the crank as well. Just my 2 cents.

 

[Gamerse]

Rob, your thoughts about the oil may be correct. There is a whole thread about the 787 stickied. Probably worth a look. These engines pull out with a couple of lines, one electrical connector, the exhaust, starter, and engine mounts. You will be surprised how fast they come out.

Odds are, if your starter gear was covered in oil, the stator pickup is fouled with oil. Pull the front engine cover and have a look at it. You can check shopsbt.com for cheap replacement parts, or use the forum store to buy OEM. If you sign up for premium membership, you can download the factory service manual. Good luck!

 

[rtoth]

Update: this weekend my brother and I removed the mag cover and found a bunch of fragments to the spring from the crank seal. We assume the seal dried up as the motor has never been opened before and the previous owner basically had it sitting at a dock for the past three years and it got little to no use whatsoever. We then proceeded to remove the motor and during the week we will take off the flywheel and get a good look at the crank seal and what's left of it. I don't think the bearings have gone bad there doesn't seem to be any play at the flywheel. Wish us luck. Does anyone out there have a straightforward procedure to bleeding the oil system?
Thanks for all the imput so far!

 

[parrothd]

You'll need to split the cases to replace that seal(at least from what I remember) and if you're going to split the cases you should buy a rebuilt crank because the other seals will likely fail especially after spiting the cases, and if you're going to replace the crank you should rebuild the top end....See where I'm going with this.....

 

[rtoth]

In that case, would it not make more sense to pick up a complete, brand new replacement longblock (Goes for $1200)?
http://parts.perryperformancegroup.com/pages/OemParts?aribrand=BRP_SEA#/Sea-Doo/Speedster%2c_5615%2c_1998/01-_Crankshaft_And_Pistons/5843/10177

 

[wildone72]

Just buy a replacement from SBT or someone.