upgrading crankshaft oil seals

[brens_gbikes]

I found my air leak, it's around the oil seal on the magneto side. didn't even check the other side. i'm looking for better seals. The ones everyone sells for these engines seem dubious. Reviews indicate that new ones wear out easily.

has anybody tried these? i keep finding them mentioned. but I can't find anyone giving updates on if it worked or not. i see smolik sells them on ebay, he says they work if you shim the magnet with a washer. but I don't need his price markup. Shall I be the guinea pig?

or are there better ones you know of to use?

 

[robe]

I'm not sure, haven't had to change any yet. If you search this site I believe ImpulseRocket has commented extensively on the subject of seals and bearings.

 

[DAMIEN1307]

I'm not sure, haven't had to change any yet. If you search this site I believe ImpulseRocket has commented extensively on the subject of seals and bearings.

I would agree... @ImpulseRocket is the one to ask about good quality seals and bearings.

 

[ImpulseRocket]

I would agree... @ImpulseRocket is the one to ask about good quality seals and bearings.

I use the same seals most people use on these engines. If the crankshaft is true, and the crank bearings have all seals removed so oil can get to the seals, and even the tiniest bit of grease was put on them during assembly, they should last a good while.

 

[DAMIEN1307]

the crank bearings have all seals removed so oil can get to the seals

HUH ???...lol.???

 

[ImpulseRocket]

HUH ???...lol.???

Most of these engines come with crank bearings with one of the two bearing seals still installed on the outside. This generally means that no oil can get to the seal surface, and the friction ruins the crank seal.

 

[brens_gbikes]

Most of these engines come with crank bearings with one of the two bearing seals still installed on the outside. This generally means that no oil can get to the seal surface, and the friction ruins the crank seal.

interesting. I never took apart the bottom end. Guess it turns out I shoulda.

 

[ImpulseRocket]

interesting. I never took apart the bottom end. Guess it turns out I shoulda.

Most people don't. They sell you on the idea that these engines are just ready to go, but so much is half-assed in the name of cheapness that there is much that can be improved if you are willing to put in the work.

 

[brens_gbikes]

Most people don't. They sell you on the idea that these engines are just ready to go, but so much is half-asked in the name.of cheapness that there is much that can be improved ifbyou are willing to put in the work.

yea. and see this is something I would not have known about even if I had. Maybe I should tear the engine down and rebuild it. I just dread that. I'd like it to run right though, for once. what are the chances you think that I could take the case apart, unseal the bearings, then put it all back together without getting new gaskets and what not? it's only got maybe 5 hours of run time.

 

[Chainlube]

yea. and see this is something I would not have known about even if I had. Maybe I should tear the engine down and rebuild it. I just dread that. I'd like it to run right though, for once. what are the chances you think that I could take the case apart, unseal the bearings, then put it all back together without getting new gaskets and what not? it's only got maybe 5 hours of run time.

Don't even think about taking it apart without new gaskets, even though it can be done. The most that can happen is your rebuild will be stalled a day or two waiting for the gaskets. If you have them in your hand, then there won't be any that get broken. The worst one is the one between the cases, a new one has a little bridge where the rod goes and it has to be cut out.