I have an anti wet sump valve courtesy of RGM on my Atlas.
I've just emptied the oil tank and sump in lieu of an oil change and realised the pump will be dry unless I prime it before starting the engine. Obviously, with the valve in place no oil will gravitate down into the pump when I fill the tank up. I suppose I'll have to remove the valve again and pour engine oil into the oil union pipe, or is there another way?
Why should the oil pump be…
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I left it for a few hours…
I left it for a few hours while the sump dripped dry. Maybe the oil all drained out of the pump during that time, I dunno.
If the pump has wear in it (and it probably has some) then it could have filtered down and out of it and emptied through the sump hole. I've never opened the cases up to check the state of the pump. It returns oil to the tank, I know that, and the engine has never clattered excessively or seized.
TBH, I'm probably overthinking this. I'll just remove the RGM valve, prime the oil union feed pipe and quit waffling.
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It is important...
... to ensure that the pipe feeding the pump is full of oil and has no bubbles otherwise the pump can cavitate. Velocette singles, which have a valve as standard, stress this in their maintenance manuals. So priming as you suggest is a good idea.
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rgm anti wet sump valve and oil change
I have the velocette anti drain valve fitted direct to the oil tank on my Dommi. If the bike has been standing for a while with an empty oil tank I usually remove the sparkplugs and crank the engine over until I see the oil returning to the tank. Then carry on cranking whilst holding a finger over the oil tank return to lubricate the rocker box.
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Once you have drained the…
Once you have drained the oil tank, the head of oil that helps push it through the pump is no longer there. Cannot imagine that the little oil left in the pipe will find its way past the pump, through the crank and into the sump.
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Velo
Seems the RGM item works the same way as the valve the factory fitted on Velocettes. On them it is important to make sure that the pipe between valve and oil pump is filled with oil. Otherwise the pump is incapable to suck oil. Not so detrimental on a Velo as it has a roller bearing crankshaft. You can ride them a few miles before seizing. When checking oil returning to the tank you can stop them before any harm is done. The Norton heavy twin has conrod plain bearings. which will wear out very fast without oil.
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Problem solved! I filled up…
Problem solved!
I filled up with oil and she started first kick! A bit easier too this time cos I've replaced the old kickstart lever that had dodgy splines with a brand spanking new one. Within a few seconds of the engine running oil was coursing up through the transparent tappet feed line and then spurting back into the oil tank. New crush washers on the tank spigots too. No leaks. Luvly!
I think my initial fears about the oil pump being worn were unfounded. There's a good strong flow of return oil coming back into the tank even when the engine is ticking over.
Job done.
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Why should the oil pump be dry whilst carrying out this maintenance?
If the crank is not turned during this activity the pump will remain full of oil.