crank seal replacement

[tilleryrat]

ok, I've done a ton of research before asking any questions first, so here goes. I put a top end in my 01 sj 3 weeks ago (second time in 3 years) just wanted to keep up with general maintenance. When removing the cylinder case to have it honed it took taking the flywheel cover off and using a breaker bar with rag thru exhaust port to break case loose (recommended by Harry at group k). Worked great. As I am reading some posts here last night I run across the oily flywheel cover post, diagnosed as leaking crank seal. My jaw drops because when I pulled the flywheel cover earlier I had a small puddle of oil/gas mixture present. Didn't think anything of it because I didn't know any better, never been into the bottom end of one. So i'm in for a seal replacement. I also found where this can be done without pulling top end apart. Am I correct in assuming this means pull exhaust and carbs, pull engine flip upside down (make sure cylinders are level with each other), seperate lower crank case and replace seals. My questions are I assume you have to pull flywheel and stator? Is there any step by step for the actual seal replacement at that point of procedure? Do I need to worry about replacing bearings? I felt for slop when doing top end and it felt tight. Any advice would be great, and of coarse my wife has me on a really tight budget! I have oem seals already from buying a complete kit a while back.

my specs.
01 sj
group k sleeper kit
decked head 185 psi
dual 38's w/primer stock jetting needle and spring
stock pipe

 

[FyrHazard]

Subscribing to this one for general engine advise.

I just replaced the seals in my blaster and ended up pulling the cylinders and getting the crank out of the way to better clean the case halves. It could be done while together but IMO it's much easier to clean up the bottom with the crank out. It's only a few gaskets.

 

[Moto360]

Take it apart.

You can get everything very clean and less risk of getting any dirt in the crank. You will have to get the coupler off in order to chang the PTO end seals. Don't replace just one side. Your there do them both. Yes the flywheel and stator will have to come off. Really not a bad job just time consuming.

Moto360

 

[tilleryrat]

yeah I'm prepared to do both ends, and already have the seals for them. I was asking about the flip because of wanting to save the cost of base and head gasket and possibly time. What all is there to clean? It looked pretty clean from top view when doing the top end.

 

[Moto360]

You could leave the head on it you wanted and the exhaust manifold. Just heavier trying to put the pistons in.

Moto360

 

[FyrHazard]

yeah I'm prepared to do both ends, and already have the seals for them. I was asking about the flip because of wanting to save the cost of base and head gasket and possibly time. What all is there to clean? It looked pretty clean from top view when doing the top end.

The case halves are glued together with yamabond. You have to get all the adhesive cleaned off so you can glue them together again.

 

[tilleryrat]

ahhhh soooo. Will 1211 work to put back together? Are there any quirks about taking the stator off or putting on? I've had the flywheel off to have it lightened, but not the stator.

 

[oxnard111]

ahhhh soooo. Will 1211 work to put back together? Are there any quirks about taking the stator off or putting on? I've had the flywheel off to have it lightened, but not the stator.

yes 1211 is perfect.

when removing the stator just don't strip the philips heads on the screws... use a hammer impact if you feel like you're gonna strip the heads.

re install the stator screws with red loctite.

 

[tilleryrat]

what about bearings? How many people replace them while your there?

 

[tilleryrat]

bearings?

 

[SQUARE JOEL!!!]

bearings?

Crank bearings??? If so, not usually something that can be done by the normal persons arsenal of toolage in their garage. Usually requires being sent out for rebuild. Therefore done on an as needed basis.

 

[SQUARE JOEL!!!]

Dub post

 

[tilleryrat]

thanks, I'll keep it simple

 

[tilleryrat]

update

I welcome everyone's opinion on this. When separating the crank case the bottom inside case has a black spot (see image) with a dia of about 2 1/2". ??? And on the outside I have what looks like hairline cracks all over but I'm almost sure it's just how it comes from factory, whether it be paint or metal painted. But I did find one spot where the paint is bubbled slightly and kind of looks like a repair, but there is no evidence of crack on inside. Opposite side of case as black spot btw. Also some roughed up metal on the center spacer between bearings. I bought the ski from a guy in 04 who claimed it was stock. From tearing it down and the amount of corrosion around bolt areas (Florida boat) I believe him. Can anyone tell me if this is ok? Thanks

 

[tilleryrat]

anyone?

 

[klze]

hard to tell, maybe some sort of micro cracks, or just burn on spots?
but leak down test will reveal everything once all is back together!

now i would atleast inspect and grease the bearings while you are at it!
bearing should spin with freeflow without making any noise or sound!

i would replace them since its not that much at a local bearing shop!
not more than $20 a piece and you need 4 i think, and another $60-80 for machine shop to press them in, but this normaly includes making sure crank is streight and aligned using machine!

 

[tilleryrat]

bearings spin freely no noise, and I would love to replace them, but it's just not in the budget at this time. Does anyone know the approximate life expectancy on bearings?

 

[klze]

could be forever :smile:
if you don't run into any major problems like crazy overheating or a few siezes or one huge enough on top speed :smile:
and obviously assuming bearings are properly greased!! and not made in china :wave: