Sumping (wish)

Run the bike for 10 mins once a week or drain the tank if it's off the road. If you remove the sump plug make sure you have a large enough container under it, you may be surprised at how much drops out..............like all of it

In principle, a gear pump fed by gravity will always allow a certain amount of oil to pass when stationary.

If it's a concern however, I can recommend the pumps now sold by Andover Norton which are made to much closer tolerances and in my case at least have eliminated it to all intents and purposes.

No potential obstruction to an oil line can ever be a good thing, can it ?

Get a sump filter assembly with a drain plug. Then you can drain the oil easily. Better to have a sump full of oil, than no oil at all.

In all the 35+ years of Commando ownership I don't think I ever drained out the engine oil before starting. I just used to start it up and run it as low revs as possible until the oil had returned to the tank (it often smoked a bit, for 10 seconds or so). I have never blown an oil seal doing this. If you are worried it's easier to remove the spark plugs and kick it over a few times before starting up, this will pump some of the oil back first (or all of it if you kick it over enough times) this was necessary after a winter lay-up, necessary because there would be no oil left at all, in the oil tank. You can gauge how much is in the engine by checking the level in the tank. I never worried unless I could see the oil filter in the bottom of the tank, then it would be plugs out.

There is also the idea that if you leave the engine at TDC when putting the bike away it takes longer for the oil to drain, due to the 'big ends' position being at their highest, but I don't know if this actually works?

I do now have anti-drain valves fitted so no more wet sumping for my 750 Commando or my 600 Dominator

Alan.

Previously andy_chetwood wrote:

Has anyone had experience of Sump drain valves?

A chap I spoke to reckons ALL commando oil pumps leak. Somebody else suggested this was true and draining the sump was a necessary evil So.?

Andy

Hello Andy, I looked into this a while back. I have a '72 Roadster with the small sump drain plug 3/8"-16 tpi (UNC) x 1/2" which is a bit small for the sump drain plugs on the market, e.g. quickvalve.

Andover Norton do a magnetic large type sump plug with a separate drain bolt and washer (their Part No. 06.7281) which suits some earlier and later models.

I agree with those posting about anti-drain/wetsump valves but would always want a backup, i.e. a means of measuring that there was still some oil pressure present just in case the valve failed. Valve failures have occurred. I'm looking to fit one of the oil pressure sensors from Don Pender (see Access Norton). I'll post separately on this.

Andy

My best solution is to switch the ignition on and kick the bike in to life really hard, then go for a ride.

Went sumping resolved!

Regards - Paul.

The Mick Hemmings anti-drain valve fitted on my Mk 3 850 has always been completely reliable. Based on the Velocette item fitted as standard on Velos , not sure if they are still available now Mick Hemmings has given up.

Putting aside my flippant response above â I see in Classic Bike this month Rickâs big fix recommends an easy drain sump plug from Norvil.

I donât know how that works but assume it speeds up the process and makes it easy to drain out the oil.

Some good guidance on this pageâ?

http://www.norvilmotorcycle.co.uk/techtalk18.htm

Hope that helps. Regards Paul.

Hi Andy,

I've just fitted an Anti Wet Sump Valve from Holland Norton Works (www.hollandnortonworks.eu) and it seems to work well. It's not cheap (74 Euro + p&p) but it is well engineered and high quality. It simply replaces the banjo bolt in the feed line out of the oil tank.

Derek

Derek

This is all well and good but what if the valve fails? How would you know?

If you haven't I'd strongly recommend fitting either an oil pressure gauge:

This kit is reasonably priced http://www.triplesunlimited.com/index.php?route=product/category&path=60_67

or at lower cost...

The oil pressure sensor I posted about here:

http://www.nortonownersclub.org/noc-chat/technical4-commando-forum/869803376?b_start=0#454547134

Otherwise there is the potential for a wrecked engine without any indication.

Just my view of course,

Andy

Greetings,

I have had a Mick Hemmings anti-drain valve fitted to my Commando for ~ 5 years, no issue. Also have same design (obviously different package) on my M-50 (> 3 years) and will fit one to my 650SS. The M-50 used to chuck over a litre of oil on the floor on every start up if left for a bit (straight out of crankcase bearing breather all over your foot / floor! Prior to investing in a Dommy style AD valve I stripped the pump, checked all gears end plates etc. All in spec in fact very 'snug. So fitted the valve, bled as per instructions and problem sorted.

Angie still keeps these as just bought one for the 650SS, excellent quality.

Regards Steve

Provided you can ensure there is oil in the pipe between the valve you have fitted in the bottom of the tank and the pump, all well and good. But If that oil has drained away, (into the crankcase) when you start up you will get the oil return into the top of the oil tank and you will think everything is hunky-dory. 10.5 miles later you will be in tears at the side of the road calling for the AA. Crank regrind, new shells, two replacement con-rods, gaskets, and the most expensive item, time. cost of parts, about £500 (and that's doing it yourself)

With my recently overhauled engine, yesterday I covered 80 miles at a reasonable pace, when I started off, the oil pressure was about 40-50 psi, when I got to the destination, my gauge was hardly reading. So if the hot oil pressure coming out of the pump is low, and that is quite normal on the Commando, you can presume that there is little negative pressure on the upstream side of the pump sucking your wet sumping valve open. You decide

Hi Andy,

The oil pressure gauge you reference looks like one of the best I've seen.

The points raised in all of the above notes are valid, and I did think long and hard before fitting the Anti Wet Sump valve. I reasoned that engine oil pressure will vary dependent upon Engine RPM, Oil Temperature, Oil Viscosity and the mechanical condition of the engine; so I decided that oil pressure is a variable I'd rather not monitor - on the grounds that it will probably just worry me. I'd be happier with an oil warning light as fitted to my T140.

I also figured that there are many components on a Commando that could fail without us knowing, with catastrophic results, so I decided to trust the design and manufacturing engineers and fit the valve. Hopefully I won't live to regret my decision!

Cheers, Derek

Previously james_fanning wrote:

The Mick Hemmings anti-drain valve fitted on my Mk 3 850 has always been completely reliable. Based on the Velocette item fitted as standard on Velos , not sure if they are still available now Mick Hemmings has given up.

Hi. Mick is still going to an extent , just working from home and not doing as much. I bought one of his anti - drain valves last year and so far have no problems at all. I don't recall Mick having a current website. I got his phone number though and just rang him up.