wet sumping

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Sep 20, 2005
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Hi guys, when your commando has been sitting a while and the oil is in the sump (assuming there is no anti wet sump valve) do you start it up and let the oil recirculate back into the tank (without revving as to avoid building up too much pressure to blow a seal) or do you pull the sump plug to drain the oil and refill the tank?

I remember seeing something on this topic but couldnt find it again.

Thanks

Mark
 
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Mar 21, 2006
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I always remove the small crankcase drain plug and run out all the surplus oil before firing the engine. I think it is less likely to cause high crankcase pressure and certainly avoids plumes of oil smoke bellowing out of the exhaust, as excessive oil is flung from the crankshaft up into the bores. The engine also cranks easier if the crankshaft is not sitting in a puddle of oil!
 

L.A.B.

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fourperf said:
Hi guys, when your commando has been sitting a while and the oil is in the sump (assuming there is no anti wet sump valve) do you start it up and let the oil recirculate back into the tank (without revving as to avoid building up too much pressure to blow a seal) or do you pull the sump plug to drain the oil and refill the tank?


If I know I won't be using my Commando for a while then I usually transfer the majority of the oil from the oil tank to a clean container with an oil suction gun http://www.machinemart.co.uk/product.as ... 2056&g=107 which saves me the trouble of going through all the unnecessary palaver of draining oil from the sump
(Of course you do have to remember to put the oil back in the tank before the next start-up!).
 
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L.A.B. said:
fourperf said:
Hi guys, when your commando has been sitting a while and the oil is in the sump (assuming there is no anti wet sump valve) do you start it up and let the oil recirculate back into the tank (without revving as to avoid building up too much pressure to blow a seal) or do you pull the sump plug to drain the oil and refill the tank?


If I know I won't be using my Commando for a while then I usually transfer the majority of the oil from the oil tank to a clean container with an oil suction gun http://www.machinemart.co.uk/product.as ... 2056&g=107 which saves me the trouble of going through all the unnecessary palaver of draining oil from the sump
(Of course you do have to remember to put the oil back in the tank before the next start-up!).

I like the suction gun idea. Would you also not fire it up to recirculate the oil L A B?
 

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fourperf said:
I like the suction gun idea. Would you also not fire it up to recirculate the oil L A B?

I like to put the oil back in the tank so that it has time to find its way down to the pump by gravity before starting up if I can, but I don't see any need to start up especially to recirculate the oil as it should be up to pressure in a few seconds whenever the engine is started, and I don't remove all the oil, so some of the oil left in the tank will find its way down to the sump, which hopefully allows for a bit of extra initial splash lubrication on start-up.


One tip when using the suction gun like the one shown, is to fit some sort of restrictor nozzle to the end of the tube, as even cold oil can spill out of the gun quite easily, making the job rather messy with the normal bore tubing.
 
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