Changing the crankshaft seal - dry belt drive

Hi all,

I've got a leak coming from the crankshaft seal. I'm also running a dry belt drive.

Is there anything I need to be careful of here after I remove the primary cover?
I've got the repair manual and will read this thoroughly before I start but as everyone knows the books always don't cover it all and considering I have a dry belt drive I'm not sure if that changes anything.

Thanks

If you haven't already, correct the breather problem. Many previous posts on how-to. Getting rid of positive crankcase pressure will usually take care of what appears to be an oil seal problem. You can replace crankshaft seals until you are dizzy, but it won't cure the leaking if the crankcase is pressurized. In short, it ain't the seal that's the problem.

Thanks for the heads up JimC. I didn't change them over but checked out some early posts like you mentioned. Posts kept pointing back to the pressure build up being caused by the additional oil being stored in the crankcase and putting additional stress on the sump and magnetic bolts.

So I drained out the oil in the crank case and topped the oil up to the medium mark because people were commenting that filling up the oil more past the Medium mark caused or contributed to the crankcase leaks.

So far there aren't any oil leaks but it's only been about 9 hours so I'll check it tomorrow evening and see what's going on. Fingers crossed that fixed it.

BTW I fired up the bike for the first time today. It sounded so sweet, like music to my ears.
I'd imported the bike to Australia from Canada and hadn't had a chance to get it fired up due to work and family commitments. You know the usual stuff that keeps you away from the bike.
Now to learn how to wire up indicators so I can the bike down for registration so I can ride it.

JimC said:

If you haven't already, correct the breather problem. Many previous posts on how-to. Getting rid of positive crankcase pressure will usually take care of what appears to be an oil seal problem. You can replace crankshaft seals until you are dizzy, but it won't cure the leaking if the crankcase is pressurized. In short, it ain't the seal that's the problem.

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if your leak is when it sits over a long period of time than the breather mod wont fix it but still well worth doing. from what you posted it sounds like it leaks when it wet sumps ( how much oil did you drain out of the crankcase) if this is the case than you will need to replace the crank seal and make sure that you lock tight the 3 small bolts that retain the inner primary case along with the lock tabs.

windy

Oil in the primary. I doubt a seal will let oil pass when the bike is not running. If it does, you definitely need to replace the seal and seal the the 1/4-20 bolts, as Bill said. Here again, it's not the seal that is the original sinner. Gotta stop the wet sumping and prevent the crankcase from being pressurized.

I spent a lot of time and money replacing seals. Convinced if I could just get the right seal I would stop the oil leaks. I even tried some super expensive teflon seal, to no avail. Finally, I sent the timing cover off to AMR for their anti-sumping mod. Still had some wet sumping, even with a new oil pump. Then sent pump to AMR for the mod. Now, no more wet sumping. Still getting oil in the primary (belt drive), I tried a Motormite brake checkvalve. It worked for a very short time, few hundred miles. Finally, I installed the Yamaha PCV valve. Now I've got a dry primary. I also did the oil pickup mod and breather location mod, per Old Britts, some time after the PCV valve installation. The Old Britts mod has more to do with oil scavenging and getting the breather out of the oil than wet sumping or positive crankcase pressure.

I'll have to check out this Yamaha PCV valve fix.

The bike was sitting there for a while. There was also a lot of oil in the sump. I didn't measure it but I'm about to head down and check on the bike in a minute and will see if I can check how much oil came out of the bike.