Wet sumping

I know its a well talked about subject but can I ask for opinions on what are the best options to cure wet sumping on a 750, ie. is it worth fitting the late type timing cover as per 850's, or an oil line valve, tap or whatever?

thanks,  Ralph.

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

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.

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"!

Previously wrote:

I know its a well talked about subject but can I ask for opinions on what are the best options to cure wet sumping on a 750, ie. is it worth fitting the late type timing cover as per 850's, or an oil line valve, tap or whatever?

thanks,  Ralph.

 

tips are to use SAE 50 oil and leave the pistons at the top of he cylinder using the kickstart. can't recommend anti drain valve - potentially delays pressure build up by pump on every start after a rest and there instances recorded of it causing catastrophic oil 

starvation

A few comments as a long time '76 Mk 3 850 owner in Kenya from mid 1980s to 2006 - had these usual wet sumping problems due to sporadic useage owing to frequent bus trips around Africa. Rebuilt the bike after buying it from the Kenya police in '83 who were re-equipping with BMWs. Used to start her up after one or sometimes two months standing then wait a minute or two till the thick pall of blue exhaust smoke had cleared from the neighbourhood , do a quick oil level check with top-up if necessary , then off I'd go. Gave her some pretty tough rides on mostly poor and potholed tarmac roads , eg , Mombasa - Nairobi , 490 kms , in 4.5 hours (excluding three 20 minutes stops for a pee and refreshment).  

Used to change engine oil at 1500 mile intervals using 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 me and had it professionally rebuilt. Upon collection , after an excellent rebuild, I enquired about the state of the engine found during strip down and was told it was in good shape. Standard bore was still retained with new rings , bearings , topend overhaul , etc - camshaft OK after I'd replaced it in Africa.

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