90 650SJ-Blowing out rear crank seals

[quickSX/XP]

Wondering if you checked on which way the outer seal faces? Let me know
Thanks

[torquenut]

Dude your are describing my posses boat I have. OK I built up this 61X nex gasket new seal etc etc. I fired her up once I accelerate, hiss and backfires bad, cannot reach full power. My rear seal is ok. I changed everything from new electricals to head gaskets to cranks, exhuast, carbs the works. The one thing I did not change is the cylinder. I think here is my problem. The cylinders might not be the same and I remember that I got them from a friend and he told me they were ported. I'm planning on using a complete new cylinder. If you want hit me up at my email. torquenut3@aol.com looks like we have the same gremlings at work. [img]tongue.gif[/img]

[quickSX/XP]

Torquenut, our problems are different. Mine ran excellent throughout the powerband and then all of the sudden power was gone and I pulled it to shore and the seals popped out.
Anyways, I am back from school and was able to check on the proper installation of both seals. The legs on the single lip inner rear seal face out(the only way it will go into the grooves in the crankcase) and the outer double lip seal has the spring facing the outside(the only way it will fit into the crankcase grooves) One cannot put the rear seals on this ski backwards the outer lips around the circumference of the seals will never seat in their respective crankcase grooves... Meanwhile I am starting to think the crank I put in is somehow causing the seals to come out?? Even though it ran great and checks in phase. Besides the pulser coil, new reeds, and a carb rebuild this is the only thing I changed from the original setup that ran great for years. ???

[Technical Support]

The only way the crank can cause that is if it was dropped, and is now out of index.

[torquenut]

Well I hope I have my gremlins figured out. I need to build a 1200 and them I'll tackle this beast once again. The boat that is was on I just took out the engine put a 62T and sold it. The posses engine has been sitting under my work table for almost eight months, so maybe this will be the summer I figure out the problem. I'm just fortunate I have bunch of stuff on hand becouse I changed a bunch of stuff, with no results. Hate to shootgun a problem but at this point is all I have. :D

[Technical Support]

Looking in the Manual, this is how they go in:

[Bill O'Neal]

I use Gasket Cinch, it is a yellow glue-like gasket coating. I put it on the outside diameter of the seal. In effect, it glues the seal to the cases, and it works excellent.

FYI, on some old 1988 models of 580 SD motors, they used small screws with flat washers, screwed into the outside of the cases with the flat washer overhanging the outer edges of the seal to retain the seal in the cases and prevent it from getting dislodged. You might try that method.

In all later models, they use a flat aluminum seal retainer that fits into a groove behind the seal to retain the seal.

[ March 05, 2004, 10:15 AM: Message edited by: Bill O'Neal ]

[quickSX/XP]

Thanks for the diagrams and tips. I am going to get new seals coming and hopefully they will stay in. I will let you guys know if it works.

[John Kubiak]

Beleive it or not, it is possible that you got the bolts for the engine mount brackets to the crankcase mixed up with the cylinder base bolts.....The cylinder base bolts are slightly shorter, by about 3 to 4 threads, so if you mix them up, it is possible to bottom the bolts in the crankcase before the bolts actually clamp the cylinder base down. I see this quite frequently in the classroom. This could account for the hissing/backfire issue.

[ March 07, 2004, 08:10 AM: Message edited by: John Kubiak ]

[Bill O'Neal]

Nice catch John. I have seen that too.

[Chester]

Originally posted by quickSX/XP:
I installed the inner seal with the arms facing out(the only way it will go) Then I installed the outer double lip in its grove with the spring facing out. I did not silicon them in this time. I did the last time with no luck. I have never done that to any engine until this 650 came along. Just curious what coil does the CDI use under 2500 rpm. Could a coil that is breaking down intermitently cause a bad enough misfire to blow the rear seals. Although it did run quite well. If the front crank seal was set up the same way it might have blown out for the same reason but since the stator is right in front of it it has no where to go. Should it matter if I am using a 62T CDI. That is what was in there since 95 or 96. along with several other mods. Also the couplers are lined up correctly The last crank was the original and the pump has not been out in years. I appreciate the input, several minds are better than one...

That seal with the tabs is the outer seal, not the inner seal! If you put the seal with the tabs on the inside they will blow out every time. Put it back together with new seals and the springs facing out. Make sure that, once assembled, you can still see the tabs.
BTW, this rule does not apply to the Kawasaki seals with the tabs.
Chester

[ March 07, 2004, 05:43 PM: Message edited by: Chester ]

[quickSX/XP]

Thanks for the info. Chester. The Clymer manual is dead wrong. I guess there is no purpose for the tabs on these seals. I have rebuilt Kawasaki 650's and Tigershark and the tabs seat against the bearing. As for the mismatched bolts this was not the case. It ran great after I put the pulse coil in it. The seals were just put in backwards so I guess that is the only reason why they blew out. Thanks again. Looks like my problem is solved once I get my new seals.

[torquenut]

Dude I'll check, tonight.
I know four out of the six are smaller and two are a bit longer. I never measured them against the craddle bolts.
Thanks and if this is the case then your a God send, as this has kick my rear end. :D

[quickSX/XP]

Update... I put the seals in the way Chester described (not the way the Clymer manual states!!) and I have had no problems, runs great. The ski has about 2 hours on it since reassembled [img]smile.gif[/img]

[BULLRAIDER]

I knew the manual was wrong,but as I stated THEY DONT CARE..!!!!!!!they are not responsible for bad information................WOW!!!!