Wet sumping

Constant use equals no more wet sumping!

Seriously use it more and this problem more or less dissapears, or even start it and listen to the music for 5 minutes, great therapy!

I must agree with Gino. As far as I can tell Nortons and other British bikes have always had a tendancy to wet sump. sometimes you are lucky and it takes a long time before it happens sometiems it happens quickly. However, when they were new bikes were much more likely to be used daily and the problem wasn't as apparent as it is when you don't use a bike frequently.

Ralph, you can throw a lot of money at this problem and still fail to cure it. Used daily I'm sure your Commando will not end up with a sump full of oil!

Ian

Slightly off topic - Would it cause any damage if the bike was started with the oil tank contents in the sump given the limited capacity of the "dry sump"?

You would probably find that much of the excess oil in the sump is blown out of the breather pipes, usually saturating the air filter and/or dumping a puddle on the ground. Also. it's likely, there would be lots of smoke from the exhaust. It's better to drain the excess oil from the sump into a clean container, and return it to the oil tank before starting the engine.

Would there be a potential for damage to the crankcases due to too much oil in the sump? Trying to find out whether it is essential to drain if wet sumping has occurred. If draining is the only option I would not be willing to return said oil to the oil tank. rather replace with new.

Previously wrote:

Would there be a potential for damage to the crankcases due to too much oil in the sump? Trying to find out whether it is essential to drain if wet sumping has occurred. If draining is the only option I would not be willing to return said oil to the oil tank. rather replace with new.

Why replace with new oil? After all , it has not been used since the engine was last run. If you are not going to use the bike, for weeks on end, the best option would be :- Drain the oil into a clean container, while still hot (no need to remove the sump plug, a it will not yet have started to fill).

As stated, in previous posts, the best solution is to use the bike! "Wet sumping" was unheard of in the 50's, in those days bikes were meant to be ridden, not "boy's toys"!

Hi folks!

I am using the RGM antidrain valve which is of a certain help. I grinded the ball seat seriously to give it a round shape. Normally it prevents the oil drain for about 3 months. But if you consider end October to beginning of March you should drain the crankcase anyway before a new riding season. Best method as Gino and Ian already wrote: Daily use!

Afew comments as a long time'76 Mk 3 850 owner in Kenya from mid 1980s to 2006- had these usual wet sumping problems due tosporadicuseageowing tofrequent bus trips around Africa.Rebuilt the bike after buyingit from the Kenya police in '83 who were re-equipping with BMWs.Used to start her up afterone or sometimestwo months standing then wait a minute or twotill the thick pall of blue exhaust smoke had cleared from the neighbourhood , do a quick oil level checkwith top-up if necessary , then off I'd go. Gave her some pretty tough rides onmostly poor and potholedtarmac roads, eg , Mombasa - Nairobi , 490 kms , in 4.5 hours (excluding three 20 minutes stopsfor a pee and refreshment).

Used to changeengine oilat 1500 mile intervalsusing a Castrol 20/50 mineral available out there. The Mk 3 anti-drain valve in the timing cover never worked very well despite renewing both spring and cup during rebuild.

Brought the bike back to UK in 2006 when Africa days were over for meand had it professionally rebuilt.Upon collection ,after an excellent rebuild,I enquired about the state of the engine foundduring strip down and was told it was ingood shape.Standard bore was still retained withnew rings ,bearings ,topend overhaul, etc - camshaft OK after I'd replaced it in Africa.

Also have a '73Mk 1A 850 whichsuffers the same wetsumping after afew weeks standing- as has been stated ,the only way to cure this is regular use !

Hi,

I have an 850 MkIII, had it from new so I know the state of the innards.

When the machine has not been used over winter I look in the tank and it is close to empty. I then start the bike but keep the revs as low as possible. I watch the oil return until it changes from a steady stream to spit and splash showing the sump is now dry. Then just ride it.

It tends to smoke a bit from the left hand pipe until it is running dry but I have never hadproblemswith seals. and I have not seen oilcomingout the breather (Which on the MKIII goes into the tank anyway).

So keep the revs low until it stops smoking and away you go.

Regards

Tony