Crankcase seal to primary

Hi all
Apologies for posting such simple questions, but I dont see the answer on this forum or elsewhere.
It seems I have a leak from the crankcase into the chain case through the crankcase seal, and which follows wet sumping after a month sitting. I am likely to have to let teh bike sit for extended periods - 2-4 weeks simply because f its location That means after every break I get wet dumping, hence leaks, the engine oil screwing up my clutch action, and seemingly the ned to drain, clean reassemble.
My question is - is that a problem I can avoid. Will even a new crankcase seal allow wet sumped oil to leak through anyway? Any suggestions for the next step? From what I see in the parts book, getting to the seal is going to be an issue, let alone replacing it.
Again apologies if my questions are a bit naive

My 750 wet sumps within a few days of sitting (not now because the engine is on the workbench)
Have you tried bringing it back onto compression after you shut it down so the crank journals are at a high point,might be a wives tale.

You just have to ride it more. If mine sits more than a week, I drain the sump and pour it back in the tank. Easy fix.

Ok I will check my spelling before posting in future - nobody wants to hear about wet dumping. Draining pre ride seems like a simple solution. Any value in staining/trying to ensure clean oil - if so whats best

DrMike said:

Any value in staining/trying to ensure clean oil - if so whats best

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I wouldn't worry about staining the oil you get out of the sump; just make sure the pan you catch it in is clean first. The oil in the sump came from the oil tank - it's no dirtier than that.
Nathan

You can replace crank seal pretty easily through primary.
Drill small holes in metal portion of seal, screw in a couple of screws and pull out.

As to the wet sumping. You can put a check valve in the line from the tank.
There are automatic ball valves LCommando Specialtiesand others) that open when pump sucks or manual ones.
The automatic may fail and you won't know until engine seizes and manual one's can be accidentally left closed with same results.
There are a number of threads on the subject with a lot of different opinions on best approach.
You could get at oil pump and lap it to better fit which could be your solution. Threads on this site describe how its done.

DrMike said:

Hi all

My question is - is that a problem I can avoid. Will even a new crankcase seal allow wet sumped oil to leak through anyway? Any suggestions for the next step? From what I see in the parts book, getting to the seal is going to be an issue, let alone replacing it.
Again apologies if my questions are a bit naive

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If static oil is passing the seal when the sump fills then the seal has seen the end of its useful life and is not working as intended.
It should easily prevent static oil passing from the crankcase regardless of the oil level. If you start the engine with a full sump that's a whole different situation.
The amount of static oil against the seal is greatest when the oil tank drains and the sump fills up so to avoid this over long periods you would need to either drain the oil before it pools in the crankcase or leave the sump plug out. Remember to put oil back in before use or life will suck.
Or just replace the seal if that is the only reason for the leakage and remember to drain the sump before each use.
The crank rollers are real close to the back of the seal so if you drill do so with great caution.
Lisle make a seal removal tool 58430 (for less than US$20) with a lip that will take the seal out without damaging anything when properly used. Not a brand specific recommendation, no affiliation, just a happy owner.
All the best.

"Draining pre ride seems like a simple solution. "

Although I know some people do that, I'd personally consider that a total PITA. I have never drained oil out of my bike and it sits for months without use. Yeah, it's a little harder to kick initially and yeah, all the oil is now in the sump. But instead of being a one-kick starter as usual if it's been run within a week or two, it is a 3 or 4 kick starter. I have never seen any evidence that wet sumping actually creates any problem at all and I think it's much ado about nothing. I realize others do not share that opinion...

As far as the crank seal itself, yes, if oil is leaking past it into the chaincase, the seal needs to be replaced.

Are you sure it's the seal? Lots of times it's the bolts that hold the inner primary on. I replaced my bolts with studs and nuts, and used red locktite on the crank case side. A hobot trick. Or you could just try gooping up the bolts with something leak proof.

re the bolts - I've become quite fond of Permatex Motoseal 1; I use it for just about everything that needs a sealant; it is NOT a silicone. It's basically Hondabond or Yamabond but costs less. It's become my go-to for just about any sealant purpose and it has made my Commando a non leaker!

If you do replace the crank seal I would suggest to use the one with the metal and not a all rubber outside. I tried both and the best way was to use the stock one and put a dab of know weld around the edge.

To get the old one out I used a small self tapping metal screw and just drilled a tiny tap into the seal then screwed the screw into it. I yanked the seal out with a pair of pliers.

I also did the hobot trick with the three screws holding the primary case. Those do leak and when converted to studs and sealed they are tight.

Mines been tight for many miles now.

Oh and also on threaded things like the sump plug and primary drain plug I use liquid Teflon and not the tape. 100% difference. I use the yellow stuff.

iceteanolemon said:

Oh and also on threaded things like the sump plug and primary drain plug I use liquid Teflon and not the tape. 100% difference. I use the yellow stuff.

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Now that's a good idea.

DogT said:

iceteanolemon said:

Oh and also on threaded things like the sump plug and primary drain plug I use liquid Teflon and not the tape. 100% difference. I use the yellow stuff.

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Now that's a good idea.

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Comnoz suggested that with his sump breather. I like the stuff so much I don't buy the tape anymore for anything!! haha