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Sumping (wish)

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Sumping (wish)

Posted by andy_chetwood at February 14. 2017

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

Re: Sumping (wish)

Posted by david_evans at February 14. 2017

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 itSurprised

Re: Sumping (wish)

Posted by richard_payne at February 14. 2017

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 ?

Re: Sumping (wish)

Posted by christopher_winsby at February 14. 2017

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.

Re: Sumping (wish)

Posted by Alan Throssell at February 14. 2017

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 Smile

Alan.

Re: Sumping (wish)

Posted by Chris Grimmett at February 15. 2017

It's a fact of life that when something gets off to a bad start, it sticks with it for ever.  There were certainly some bad experiences with early anti-drain valves, there is no denying that.

However, with more thought given to the designs and in the light of the problems, it has to be the case that there should be no problem with fitting a reputable anti-drain valve if you want to go that way; and many of us use them all the time quite successfully.

However, Richard's point about any obstruction in an oil system being a bad idea is valid.  I had never paid much attention to my oil pump until Phil Hannam wrote his article in Roadholder 327 about refurbishing them.  As I subsequently wrote in a letter to the Editor, going through Phil's procedure made a huge difference.  It will never be quite as good as an non-return solution, but for the cautious it's a good compromise.

Re: Sumping (wish)

Posted by Andrew Heathwood at February 15. 2017

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 modelsFrown.

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

Re: Sumping (wish)

Posted by paul_smith at February 18. 2017

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.

Re: Sumping (wish)

Posted by james_fanning at February 19. 2017

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.

Re: Sumping (wish)

Posted by paul_smith at February 20. 2017

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

I don’t 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 page…

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

Hope that helps. Regards Paul.

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