My 850 wet sumped and I had a massive oil leak. Two questions.

[Kurt V]

1973 850. I forgot to check my oil tank and must have wet sumped. I only discovered this after coming back from a 40 mile ride and watched oil puddle on my garage floor. Not drops, a large puddle about 4 inches across. All from the left side of the bike. There was oil dripping off the chain, swingarm and even some off the fender on the left side. So much, that it was impossible to identify where it came from. I drained my primary and got about twice the amount of oil out that should be in there. But my oil tank was about a quart low and there was oil all over the left side of the bike. I decided to go ahead and drain all of the oil out of the primary, the oil tank, the crank case and pulled my oil filter. I went ahead and removed my rear tire and rear fender so I could give a close look to the oil lines. I checked all of my oil lines and they look fine. So here are two questions:

1. How did all of the oil escape out of the primary? I did some research and understand there was a felt seal behind the clutch where oil can escape if the primary gets overfilled. But can it really be that much? Is there anywhere else the oil could have escaped on the left side? My oil lines all appear to be in good condition and tightly fastened.

2. To drain the rest of the oil out of the crank case I removed the smaller of the two plugs on the bottom. Not the 1&1/2 inch plug, the 9/16 plug. Is there any reason why I should remove the larger plug also? Thanks for everyone’s help and advice.

 

[Tornado]

Likely you've blown out the crank seal in the primary casing side. Had mine split in half from a wet sump situation and like you, had oil spewed out over rear of bike. It escapes from the primary felt 'seal' as it fills up the primary case. Not it doesn't need to fill up to the seal level as it is throw all around by the chain etc. Your clutch plates will also be contaminated.
Need to pull primary out and remove clutch & alt/rotor and sprocket to access the cransk oil seal. It is a simple remove, replace. Some advise a little locktite or epoxy on seal outer edge to help keep it in place. Mine was split in half, so likely old and brittle.
I've since fitted an oil feed manual shut off with ign interrupt to prevent this potentially serious accident inducing situation.

Only other way for oil to fill primary is from the three small bolts holding inner primary to crankcase. These can loosen and fall out, allowing oil into primary and causing damage to primary moving parts like chain and sprockets. Use locktite on these bolts in addition to the locking tab washers for extra insurance.

 

[Mike40M]

Seen the same overfilling of the primary from a blown crank seal on a 650SS. Also due to wet sump. With inspection cap removed I could see a lot of oil whirling around.

 

[ashman]

Always check your oil tank before any ride and if the bike has been sitting for some time to drain your crank of any access oil that may have filled up from sitting, I normally do that the night before any big ride but mine only wet sumps if I let it sit for 4 months or more, its all part of owning a Norton and seems like you have blown your crank seal or the bolts that hold your inner primary case could be leaking pull them out and seal the threads before refitting them, remember only 7 floz in the primary for chain lube to splash around on the chain, the felt seal won't stop over oil in the primary and will blow oil out of it when the primary is over filled and make a big mess on your rear end.
A simple check before any ride will save you a lot of pain later.

Ashley

 

[Peavey Jeltz]

2. To drain the rest of the oil out of the crank case I removed the smaller of the two plugs on the bottom. Not the 1&1/2 inch plug, the 9/16 plug. Is there any reason why I should remove the larger plug also? Thanks for everyone’s help and advice.

No need to remove the big plug which just contains a wire mesh strainer for the oil scavenge feed to the pump unless you're searching for shrapnel.

 

[RoadScholar]

No need to remove the big plug which just contains a wire mesh strainer for the oil scavenge feed to the pump unless you're searching for shrapnel.

I have to disagree on your point, with a degree or deference. If the OP hasn't, yet, then I recommend removal and inspection of the mesh screen. As the scavenge side of the oil pump has greater volume capability then the feed side I'd want to know if the sump mesh filter plug ( the large one) played any part in the OPs chain of events.

Best.

 

[Kurt V]

That’s a good idea to go ahead and check out the mesh screen. Hopefully I don’t find anything other than oil!

I figured as long as I was in there I might as well just replace the clutch plates, install a new felt washer and a new inner primary gasket. I’ll go ahead and seal up the three bolts that hold the inner primary and also seal around where the alternator wire goes through the primary case.

 

[jseng1]

The easiest solution to the mainseal blow out problem is to install a viton Oring between the engine sprocket and the crank main seal as shown below. This prevents the oil seal lip from inverting. The 1/16 x 1-1/8 ID oring restricts the clearance so the seal lip stays where it belongs. With this mod you can forget about wet sumping causing a problem (other than maybe stiff initial kickstart but its never bothered me or kept my bike from starting in a couple kicks). No problems so far.

 

[Tornado]

That’s a good idea to go ahead and check out the mesh screen. Hopefully I don’t find anything other than oil!

I figured as long as I was in there I might as well just replace the clutch plates, install a new felt washer and a new inner primary gasket. I’ll go ahead and seal up the three bolts that hold the inner primary and also seal around where the alternator wire goes through the primary case.

Might want to consider fitting a clutch rod seal (DynoDave can tell you who is supplying them currently) while in there. Eliminates gear box oil getting on plates.
Unless you want different plates, original bronze type do clean up quite well and can be reused.

 

[Kurt V]

The easiest solution to the mainseal blow out problem is to install a viton Oring between the engine sprocket and the crank main seal as shown below. This prevents the oil seal lip from inverting. The 1/16 x 1-1/8 ID oring restricts the clearance so the seal lip stays where it belongs. With this mod you can forget about wet sumping causing a problem (other than maybe stiff initial kickstart but its never bothered me or kept my bike from starting in a couple kicks). No problems so far.

I’ll add the viton o-ring to the list! Thanks!

 

[Kurt V]

Got the clutch sprocket and front sprocket off with no drama. The crank seal was so loose in the housing that it fell out when I was starting to drill a hole in it to use a sheet metal screw to pull it out! New crank seal went in nice and snug. I went ahead and replaced the clutch plates while I was in there as they are fairly cheap. Buttoned everything up and took the bike for a ride. All leaks are gone! At least for now.

 

[Chris Zet]

Hello Kurt, if the leaks come back....especially if engine oil is hot and you ride the bike a bit harder with higher rpm....check the timingside crankshaft oil seal! Mine was blown few years ago....same symptoms as in your case: oil through ds crankshaft oilseal, through primary to the gearbox sprocket to chain and to my rear tire. in my case: because of the blown ts oilseal the crankcase got pumped up with oil....

 

[YING]

Kurt,
Did you put the oring on the crank?
Mike

 

[marshg246]

The easiest solution to the mainseal blow out problem is to install a viton Oring between the engine sprocket and the crank main seal as shown below. This prevents the oil seal lip from inverting. The 1/16 x 1-1/8 ID oring restricts the clearance so the seal lip stays where it belongs. With this mod you can forget about wet sumping causing a problem (other than maybe stiff initial kickstart but its never bothered me or kept my bike from starting in a couple kicks). No problems so far.

Can you say the part number of the O-ring you use. I finally found the size (I think) in Virton, but there are many hardness values. I'm guessing V1003-026

 

[Kurt V]

Kurt,
Did you put the oring on the crank?
Mike

I did. Just used the size you described and got one down at the parts house.

 

[olympus]

The easiest solution to the mainseal blow out problem is to install a viton Oring between the engine sprocket and the crank main seal as shown below. This prevents the oil seal lip from inverting. The 1/16 x 1-1/8 ID oring restricts the clearance so the seal lip stays where it belongs. With this mod you can forget about wet sumping causing a problem (other than maybe stiff initial kickstart but its never bothered me or kept my bike from starting in a couple kicks). No problems so far.

very interesting fix, will note down the "O" ring dimensions for future reference, as won't be able to find the post in future

 

[SteveBorland]

The easiest solution to the mainseal blow out problem is to install a viton Oring between the engine sprocket and the crank main seal as shown below. This prevents the oil seal lip from inverting. The 1/16 x 1-1/8 ID oring restricts the clearance so the seal lip stays where it belongs. With this mod you can forget about wet sumping causing a problem (other than maybe stiff initial kickstart but its never bothered me or kept my bike from starting in a couple kicks). No problems so far.

This is a really good tip, thanks for that. However, trying to source imperial o-rings here in Denmark is rather difficult.
Translated to metric, a 1/16 X 1 1/8 is 1,5875 x 28,575 mm, the closest standard size seems to be 1.5 x 28mm
I don't think the OD is going to work here, too tight on the shaft.

 

[olympus]

In the UK you can get 1.5mm x 29mm Viton "O" rings

 

[lazyeye6]

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[jseng1]

The Oring
For metric I would go 29mm. 1.5mm cross section. Hardness and diameter not critical as long as its a snug fit on the shaft.