64 G80 oil leak

N0rt0nelectr@

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Started up my new to me G80 road model and it looks like it has wet sumped big time.
The primary had a good deal of oil in it when I removed the level plug a fair amount of oil came out. I have several Norton's and know that the Norton oil pump will allow the tank to empty if it sits for a long time. Checked the parts book and it looks like there is only a oil slinger to keep oil out of the primary. This is inside the engine and I don't want to split the cases so I am wondering if anyone has ever fitted a real oil seal to stop this problem? Is it even possible and if so what would it take?

John in Texas
 
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John, I don't know of any oil slinger. There is a washer/spacer 021859 between the d/s bearings which probably will stop oil leaking into the primary under normal running conditions. It will not limit ingress of motor oil if subjected to hydrostatic pressure (i.e., a high level of oil in the crankcase). My advise is not to touch this. Empty your oil tank if bike is left standing for a long time. Put a warning plaque on the h/bars to remind yourself to fill her up before running again. You could also have the oil pump rebuilt to tighter specification as this will reduce leak, but if you leave the bike standing for months, draining is your only option.

-Knut
 

N0rt0nelectr@

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I am going to take the primary off and look at the breather fitting. It could be that the fitting is loose or the breather hose has come off. Knut, you are right that I need to drain the oil if I am going to let it sit. Report to follow. Thanks for your input.

John in Texas
 
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My Norton pump G80cs has a check valve ( ball bearing and spring ) fitted just after the oil pump in the inner timong cover and it does not wet sump.
 
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My Norton pump G80cs has a check valve ( ball bearing and spring ) fitted just after the oil pump in the inner timong cover and it does not wet sump.
There are two sources of leaks internally, one is the check valve and the other is the oil pump itself (oil passing along the shaft). The amount of leak depends on oil viscosity, check valve seating, and oil pump wear. If you experience zero leak, your oil viscosity is probably high (SAE 60?) and the wear parts have tight clearances. It's a good idea to verify the check valve is working as intended. Oil pumps can be refurbished to better spec than new which will minimize oil leaks.

-Knut
 

N0rt0nelectr@

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I'm running a multi-grade oil as of now. I have never had the timing cover off so I'm not sure of the condition of the oil pump.
Going to put all motorcycle projects on hold while I work to get a new work shop / garage built.
John in Texas
 
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They all are leaking. My way is a valve in the feed pipe, but if you do that only in conjunction with an ignition cut off switch. That´s works with all my English bikes.

Jens
 

N0rt0nelectr@

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Just marking their spot, I know.
Been in contact with the steel building supplier and I am now talking to several contractors about doing the work. 30' x 30' 10' walls with a covered apron in front. Looking forward to getting the garage built.

John in Texas
 
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They all are leaking. My way is a valve in the feed pipe, but if you do that only in conjunction with an ignition cut off switch. That´s works with all my English bikes.

Jens
This is the best solution!! All my Matchless/AJS bikes are equiped with an anti-sumping tap on the oil pipe feeding and with ignition cut-out switch on it- Dealer: Andrew DOVE 41 Princefield Avenue - Penkridge Stafford- ST19 5HG -UK- Phone 01785 598616 - email andrewdove@sky.com
It's also necessary to have a magneto cover with earth connection

Jean-Paul from France
 
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Fitting an anti-sumping tap (i.e., valve) compromises safety of continuous lubrication. What happens if the valve fails? Anyone fitting one should consider this carefully. If it happens during running, you will be very lucky to escape a major engine breakdown (literally).

IMHO, a much better proposition is having the oil pump reconditioned for minimum leak, running the bike frequently (no machinery benefits from being stationary), and/or empty the oil tank for lay-ups during winter months etc.

-Knut
 
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Hello Knut,
It is a quarter-turn tap - There is no valve, only a bypass - so there is no risk -
I use them for over 15 years without problem -
Jean-Paul
 
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Jean-Paul, I don't understand. A tap is by definition a valve even if operated manually.
How can a bypass restrict wet sumping if the main stream isn't closed off?

-Knut
 

N0rt0nelectr@

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Well the garage project is on hold. Every contractor is booked way out and my job is a small fill in between bigger and better paying jobs.
So, I'm back at the 64 G80 oil leak! The primary is full of oil, so I expect that the oil pump is leaking or letting oil bypass. Could be the conical oil seal on the pump? Wish I had better parts books with pictures and not just a description! Need to check out the Andrew Dove valve or I could just use a manual valve with a remove before flight tag on the ignition switch.
Taking my wife to Hawaii for our anniversary, be back late next week.
Cheers
John in Texas
 

texasSlick

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Oil can leak into the primary either due to bad drive side oil seal, rough or scored crankshaft seal surface, from a missing inner primary cover to case mounting screw, or from non sealed threads on screws fixing the inner primary cover to drive side case.

The leaking is exaggerated if the engine wet sumps, especially if one kicks it over when it is hydraulically locked.

If the engine has been kicked over when hydraulically locked, it is possible the oil seal has become inverted.

Slick
 
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That engine should have the Norton oil pump (actually same as a Dominator pump - skinnier gears than Commando). There is no seal between the crankcase and primary - just a big washer. IMO it should have a seal. Would be easy to modify the inner primary case to be like the Commando.
 
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That engine should have the Norton oil pump (actually same as a Dominator pump - skinnier gears than Commando). There is no seal between the crankcase and primary - just a big washer. IMO it should have a seal. Would be easy to modify the inner primary case to be like the Commando.
The crankcase needs to fill up * a lot * before oil seeps into the primary chaincase - at least while bike is on the center stand. I would say if the owner is using the bike as little as this, better to drain the oil and fill her up before taking the bike for a spin.

Why and how do you want to modify the primary chaincase? It should not be leaking when using the proper gasket.

-Knut
 

N0rt0nelectr@

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I am just going to drain the oil out and only refill it when I am going to take it out for a ride. This is the easiest way to deal with the issue. I will use my label maker to remind myself to refill the oil.
Thanks to all for your input.
John in Texas
 
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