Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Oil leaking from carb

Just returned to my 2nd home to find a lot of oil that has run out of the carb. The air filter was wet & so was the air cleaner cover. Car has been sitting since September. Oil changed just before packing up. Was having some leakage from around the oil tank cap. Changed the gasket.

What causes this? What's the fix?

Heat the engine abit..shut off..wait 3mins..check oil level..might be over filled oil...

I don't know anything about S&S engines but oil getting to the carb/aircleaner must be coming from the oil vapour breather system that would have a tube going to the air filter. It sounds as though there is too much oil in the system somewhere, it may have been overfilled when the oil was changed. If there is a no return valve it may be malfunctioning and too much oil drained into the crankcase. Try draining all the oil from the tank and the crankcase, refill with the correct amount, clean up the leaked oil, and see if it re-occurs.

I had a similar problem on the road. In traffic the engine cut out on the way to the dealer for service. At third attempt it restarted with huge clouds of white smoke. I pulled into a side street & phoned the dealer. The smoke was reducing so I decided to carry on slowly, as it cleared completely I speeded up.
At the dealer they found the air cleaner saturated with oil & oil down the front of the engine. They concluded that the breather valve between crankcase & air intake had malfunctioned allowing a gob of oil to be taken in. They cleaned things up & fitted a new air cleaner & its been fine for the last year & 4000 miles. Sorry I'm unable to look at the car to check where the valve is located as car is not at home.
I also had a breaking up oil cap seal but found it before it went into the tank. Maybe another thing for everyone to check.

Tim.

British bikes with oil tanks use to suffer from oil draining into the engine if the pump & valave arrangement malfunctioned.
It sounds a bit like that. THat only happens when the vehicle is left to stand for a while.

Bike engines crank case breathers are not as sophisticated as on car engines. HD engines are "known" for oil breather problems.

This video explains:

Breathing Oil

I suspect S&S may be similar.

A significant percentage of HD owners fit a seperate oil catchpot to the breather and then let the breater vent to air. This is typical:

Breather

If/when I get a M3W I'd go this route: oil on the airfilter is unhelpful.

My Commando 'wet sumps' if left standing and I agree that some Harley engines do the same. Upon starting the oil pump then attempts to empty the oil sump and spits it out through the breather. In the case of the Norton Commando, I drain the oil after a winter standing and then refill from the top.
Hope this helps

Jethro,
Back in the day when I was a spotty 16 year old lad Triumph and Norton parallel twin owners used to suffer this problem if the bike wasn't used regularly. There was a sort of non-return valve in the oil pump, but it could fail and to repair the pump was a big job.

One solution was to put a valve in the oil return pipe, but forget to open it and the result is expensive.....

The S&S engine is a dry sump design. I hope it has a good non return valve in the oil system, but even so it can wet sump on standing, with the described result. Few owners (or dealers) will understand the idiosyncratic nature of dry sump bike engines, I suspect.

Oh, and in case anyone is wondering, this explains what a "dry sump" is:

Dry Sump

Almost all cars, other than race cars, are "wet sump".

Three speeder twins are dry sump, but most two speeder twins are total loss oiling. The oil goes round the internals and then lubricates the road...

Racer twins and folk like me have added a catch tank as one does not want to be cause of unshipment of motorbike riders. What is interesting though is the state of the oil. The oil I put in is golden and reasonably thick, the oil that comes out is as black as ink and noticeably far thinner. About 1000 miles per gallon is what's claimed, although I will be using a bit more as I keep the oil injected at a slightly higher rate as oil is cheap; rebuilds aren't.