How much oil leakage is normal?

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sammyman

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Mar 29, 2010
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This is my first Norton. However, I have had 3 land rovers, and they always say that a rover isn't leaking oil, it is just marking it's territory. I have a feeling my norton is the same way, but I don't really know how much oil is normal.

Last night after riding it for about 20 min, I parked and immediately noticed about a dime size oil, and I could see the oil dripping! By the morning I noticed about the size of two quarters oil under my bike. Is the normal? Or do I have leaky gaskets that need replacing? Thanks!
 
Although we all joke about Norton's leaking - I used to say about my '71 back in the day "If it's not leaking oil, it's out of oil!" But in reality it is possible to make them essentially not leak at all. Most of the problems, IMO, are that when they DO leak, the initial reaction is to tighten the bolts holding whatever is leaking. This usually just makes it worse because the mating surfaces are warped ( this is not just true with Nortons - try Detroit Diesel engines for SERIOUS oil leaking). Truing the surfaces involved (piece of glass plate and some wet or dry sandpaper) and a new gasket with the CORRECT amount of torque on the bolts will eliminate most leaks. The other issue is that Nortons use a ton of copper washers which, after years of tightening/loosening loose their ability to seal very well. The solution is simple - new copper washers or simply anneal the old ones. Heat them to red hot and let them cool in the air. They will seal as well as new ones.

For really troublesome seeps/leaks, Permatex Ultra Gray will take care of it. It is not a "silicone" product and it is the same stuff as Yamabond, Hondabond, etc that ensure that Japanese bikes don't leak.

Yes, traditionally, Commandos are known to leak "out of everywhere but the headlight," but you really can make them pretty much leakproof!

Welcome and good luck!!!!!
 
Where do you get your non-silicone 'Ultra Grey"??

How much oil leakage is normal?


Dave
69S
 
DogT said:
Where do you get your non-silicone 'Ultra Grey"??

Dave
69S
Click to expand...

I don't use silicone. I use Yamabond or the equivalent.

How much oil leakage is normal?


The Threebond stuff is easier to find.
 
Shinola!

I've always used the stuff Mike's referring to - and considered it essentially "Yamabond."

I bought a new tube recently because my old one's near gone - and buying "from memory," bought what Dave is showing.

Anybody know what the difference is? I really like the "Yamabond" version.
 
The Ultimate Gray MOTO seal is not silicone and it is the same stuff as Yamabond, etc or, more likely, Yamabond is the same as Ultimate gray---Yamaha doesn't make gasket materials! ;) I have used it for several years on bikes, cars, and Detroit Diesel boat motors. Great stuff. Here's the data sheet, note that it is not a silicone product ...http://www.permatex.com/documents/msds/ ... /29132.pdf
 
Mike is right.

When I restored my Victor two years ago, I left the lower end intact (it had only 5100 original miles). While I love the bike, it drips oil and requires a bed pan at bed time. When I did my Mk3 this past year, I completely disassembled the engine and sealed the crankcase halves with Yamabond, and replaced ALL seals, metal and rubber. Gasgacinch on all gasket surfaces helped as well. The Norton doesn't leak, as in not a drop.

I'll tear down the Victor (again) this Fall (rainy season here in the PNW) and use the same technique on the lower end to seal it up. The BSA is not as well built as the Norton, but I'm hopeful that a combination of Yamabond on the split cases and new seals will do the trick. Brit bikes do not have to leak oil.
 
swooshdave said:
The more obvious question is "where is it leaking from?"
Click to expand...

Bingo. Some leaks are harder to stop than others.

My 850 is not leaking one drop from anywhere. But that could change tomorrow. If it does, I will address it. I hate oil leaks and won't tolerate them on my bike.
 
maylar said:
swooshdave said:
The more obvious question is "where is it leaking from?"
Click to expand...

Bingo. Some leaks are harder to stop than others.

My 850 is not leaking one drop from anywhere. But that could change tomorrow. If it does, I will address it. I hate oil leaks and won't tolerate them on my bike.
Click to expand...

Same here. Zero oil leakage is normal for a well screwed-together machine. An oil leak is a fixable problem, but some folks tolerate the mess and the continual topping up because it's less hassle to them than doing a repair of a trashed gasket or seal.
 
Howdy Sammyman.

The standard Norton makes some serious pressure in the crankcase, do a search for threads dealing with crancase breathers. In a Norton oil doesn't leak out it is forced out faster than a tennant that fails to pay the rent. When you end up doing your engine over do use Yamabond or equivalent, but implement a sound crankcase ventilation system.

RS
 
I was wondering how many replies on this topic it would take to get to crankcase breathers...

Now we know!
 
As earlier posters have said, A Commando (and any other late 1960s / 1970s) bike shouldn't leak but there's no doubt with all the separate castings and oil lines that there are plenty of places which can. Gearboxes with the early 'O' ring system for instance will sweat after a while but there shouldn't be drips and certainly not puddles.

The Commando is not a 1930s or earlier engine and wasn't designed to leak. Engines with external valve gear and drain pipes from magneto chaincases were intended to drop oil (or at least not designed not to !)
 
grandpaul said:
I was wondering how many replies on this topic it would take to get to crankcase breathers...

Now we know!
Click to expand...

You don't think crankcase pressure is a significant component of Norton oil leakage?

How's that Megacycle 56000 cam I sold you working out?

RS
 
Of course I think crankcase pressure affects oil leakage!

I've developed a nifty reed valve, very similar to MikesXS unit, to alleviate the problem.

The cam is still on the shelf with the rest of my 880 engine bits. One of these days...
 
Just a general comment about gasket makers. I know most of the posters here have good mechanical skills and therefore realize that over use of any liquid gasket maker will squeeze excess out on the inside as well as the outside of the case being assembled. The stuff on the inside is prone to plugging up oil intakes when it comes loose. RTV is really bad for this, but any product could contribute to this. So just be aware, more is not necessarily better.

Now back to the regularly scheduled discussion about breathers...
 
IMHO RTV is a tool of the devil...not so much because it is inherently a bad product but because, as noted, it is so misused. I have cleaned out marine intercoolers that were half plugged with silicone squeeze-out. A very thin film is all that is necessary IF it is necessary at all. Generally, I don't use it for anything on an engine that I can think of though I have a tube of it around somewhere. It is handy to make electrical "grommet"s and such stuff.

The Permatex Ultimate Moto seal (discussed above) is much thinner than RTV and therefore you can't goop it onto a gasket/surface like RTV - if you do so most of it will just run off so it ends up doing a far better job without all the excess that can squeeze out.
 
Mike,
It is nice to know there is another marine oriented guy here. It seems incongruous with Mexico City!

FWIW-I like the spray on gasket maker, you have to mask off your part but you can get a nice even film with it. I am making copper exhaust gaskets for the boat this morning and will be spraying them before install.

Russ
 
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