Dominator 99 oil leak

I've been cleaning the carb and undertaking some other small jobs, consequently I've not started the bike for around three weeks. The good news is that it now starts easily and seems to tick over much better. The downside is that when first started it dumped nearly a tank of oil onto my garage floor. I topped up the tank, ran it for a while and the oil stopped leaking. I've read a number of threads around dry sumping being the cause. Can anyone confirm if this is correct or do I have another problem?

Hello for one how long has your machine been stood for , As all Norton's

Are Dry sump operation ONLY when running, so when there not running

and layed up for some time then a force knowen as Gravity take over and

there only one place this oil ends up in the sump you get around a mug

of oil in there after about a month or so, this is normal, and will not do any

lasting harm too your engine but help the lubrication on start up as most

of the parts inside your Norton engine are Slash feed , only the Large ends and Rockers are under load from the oil pump, and We engineers do not recommened fitting TAPs or Anti -wet sump devices in line to the oil pump,

Has this only MASK the problem of a ware-ing or worn oil pump, or seals

yours anna j

This is the phenomenon referred to as wet sumping, when the oil in the tank gradually leaks past the oil pump into the sump. When you start the bike, oil is forced out of the breather onto the garage floor.Overhauling the oil pump should reduce the tendency to wet sump. To save your garage floor, you could fit a later oil tank and route the engine breather to the oil tank and so that whe your bike wet sumps the oil is sent from the engine breather back up to the oil tank. I have made this modification to an 88 and 99 and it's pretty good at stopping the mess.

One thing to remember. If your oil tank looks empty because of wet sumping and you fill it with fresh oil, once you are out riding itoil from the sump will return to the tank which will overflow, lubricating your rear tyre most effectively. Hope this helps.

Thanks everyone for the input. I like the idea of using the later tank. Does anyone know where I could get one?

In the short term I'm going to keep the sump screw off and collect the oil, returning it to the tank before I start it.

Hello have you not read my threads , you can make a small catch tank , and have a outlet too the chain has a drip feed, Yours Anna J

Anna, a small catch tank and overflow to the chain is not the solution in this instance. Norton came up with their own solution with the later oil tank which incorporated an oil separator tower with a connection to the engine breather. It's a neat and simple job to fit an oil tank from a 650 or Atlas to a 99.

Previously Gordon Johnston wrote:

Anna, a small catch tank and overflow to the chain is not the solution in this instance. Norton came up with their own solution with the later oil tank which incorporated an oil separator tower with a connection to the engine breather. It's a neat and simple job to fit an oil tank from a 650 or Atlas to a 99.

I have an Atlas tank on my 99 and an Atlas chain guard, the tank breathes to the chain guard. I bought a 99 chain guard - but what do I do with the breather? What have others done?

I welded a 1" length of steel tube to the top of the 99 chainguard and then drilled through, thenfixed the oil tank breather pipe to the tube. This mimics the Atlas chainguard and directs oil mist to the top run of the chain.

Previously Gordon Johnston wrote:

Anna, a small catch tank and overflow to the chain is not the solution in this instance. Norton came up with their own solution with the later oil tank which incorporated an oil separator tower with a connection to the engine breather. It's a neat and simple job to fit an oil tank from a 650 or Atlas to a 99.

Yes but its causes frothing in the tank from the air pumped in from the back stroke of the pistons, if you do one on its own you don,t get the frothie oil mixed in the oil in the tank , yours anna j

The oil separator tower in the 650 and Atlas oil tank is specifically designed to prevent frothing. The only time I experienced frothing in the oil tank was racing a 99 with a standard lubrication setup and using Duckhams Q oil. I have never seen frothing with the later oil tanks.

Previously Gordon Johnston wrote:

I welded a 1" length of steel tube to the top of the 99 chainguard and then drilled through, thenfixed the oil tank breather pipe to the tube. This mimics the Atlas chainguard and directs oil mist to the top run of the chain.

Thanks! I take it this is worth doing, rather than just blocking off the breather as someone suggested I do saying the breather to the chain just makes a mess.

Previously Gordon Johnston wrote:

The oil separator tower in the 650 and Atlas oil tank is specifically designed to prevent frothing. The only time I experienced frothing in the oil tank was racing a 99 with a standard lubrication setup and using Duckhams Q oil. I have never seen frothing with the later oil tanks.

just remember to pop the motor up on to compression when you finished running, it reduces the time between the need to drain down . And consider a control , like a tap, if you are an infrequent runner.

The oiltank has to breath to somewhere, so to therear chain is pretty sensible. Standard Norton chainguards leave the chain very exposed to road spray so a hint of oil mist has to be a good thing. Some people add supplementary breathers and route them to the rear numberplate area. Keeps the numberplate oiled!

Previously Gordon Johnston wrote:

The oiltank has to breath to somewhere, so to therear chain is pretty sensible. Standard Norton chainguards leave the chain very exposed to road spray so a hint of oil mist has to be a good thing. Some people add supplementary breathers and route them to the rear numberplate area. Keeps the numberplate oiled!

Where did the 99 tank breath to? I don't have one so don't know.

Previously Bruce Mitchell wrote:

Previously Gordon Johnston wrote:

The oiltank has to breath to somewhere, so to therear chain is pretty sensible. Standard Norton chainguards leave the chain very exposed to road spray so a hint of oil mist has to be a good thing. Some people add supplementary breathers and route them to the rear numberplate area. Keeps the numberplate oiled!

Where did the 99 tank breath to? I don't have one so don't know.

Well i was Suppost to breath it out on to the rear drive chain thats way I said a catch tank and then on to the chain Via a drip feed a Shampo bottel would come in handy for this, along with some mods like a bit of plastic pipes and glued all in place,

yours anna j

Confucious says - "If you no see oil on outside, there are no oil on inside".

Previously lionel_yexley wrote:

Confucious says - "If you no see oil on outside, there are no oil on inside".

Hello Lionel thanks for than big spanner you throwen in the works so now dose this mean that Honda's kawasaki's suzuki's yamaha's have No oil in side them, they only leak if you crash one at speed, Or someone had a big hammer and chisle on the job some where like most brit bike have been treaded in the distant past , the only reason oil leaks out is becuse it finds a gap and the lowset point to leak from ,I had a oil leak and on fearther inspection I found in was the solder round the feed pipe had gone ,on the juction fitting so this was removed , And soilder and flux and gas blow gun bought it cost me £23 to fix but its righ now, ! Its like you tin primary chain case, if it out of line and been bashed about or the big nut over done up, then you will get oil leaks , but with a lot time and hard work you can get these chaincases so they do not leak, have fun yours anna j

The thing about oil leaks, and just about any fluids is that they all leak out the bottom!

We should not be joking about a problem of such gravity!!.

As I've said before - when you go to buy your next Rolls Royce Silver Shadow make sure you look underneath the engine. If it doesn't have oil under it - there's no oil IN it!