G11 - Excessive oil in the sump

Information relating to the Matchless G11 or AJS Model 30 600cc twin
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melsajs
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Joined: Fri Jan 01, 1999 12:00 am
Location: NORTHUMBERLAND UK

G11 - Excessive oil in the sump

Post by melsajs »

I think i have a problem with excessive amount of oil finding its way into the sump while the bike is running. I ran the bike in the workshop for a few minutes last weekend to check if the recently refurbished magneto worked (it now starts almost first kick). I removed the sump plug, as i knew it would be standing for a while, and was surprised at how much oil came out - about a mugs worth. Reading up on possible causes, i removed the oil pump, fitted new gaskets and checked it had been assembled correctly. I ran it again today and found the same plus forgetting i had removed the sump plug, ran it again and was surprised/worried about the amount of oil that came out in the 30secs it ran. Is it normal for this amount of oil to be there (i know the bike has a scavenger pump) or do i have a problem. Help!!
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dave16mct
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Re: G11 - Excessive oil in the sump

Post by dave16mct »

It doesn't seem too bad to me. There has to be some oil in the sump usually about a cup full. I would run it and check the return. Check the level in the chaincase, it should be only just touching the bottom of the chain. Give it a good run and check the oil level in oiltank and the chaincase. Don't leave it on the sidestand overnight. Don't top the oil up before running the engine for a few minutes.
Dave.
g80csp11
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Location: WEST SUSSEX UK

Re: G11 - Excessive oil in the sump

Post by g80csp11 »

a mug full is not excessive , id only worry if you feel resistance from flywheels turning in the oil , and smoke in exhaust . Think your self lucky its not a Norton 750 if i leave mine for a month i can get 1.5 pints out the sump ! , answer is usually use the bike regularly
And even my G11 if left long enough will empty tank into the sump and primary cover
g5wqian
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Location: near swindon wilts

Re: G11 - Excessive oil in the sump

Post by g5wqian »

i never really bother about draining sump on my model 30 , i do the regular maitenance on it of course but i leave it as long as it gets left in garage for between rides and then i simply start it up and let it tick over for a few minutes before i head off anywhere , i pretty much allways let it run for a bit before riding off anywhere so that the oil has fully circulated and any excess in sump has been pumped back up to tank . .
if i dont ride it for months then i will run the engine up on idle now and again and let the oil pump back into the oil tank .

i never get an empty oil tank though even after months of being parked up , mostly its allways got half tank sat in it and i dont top it up to the high level in first place or else when oil is hot and expands it will come out of breather and be splattered over rear rim .

i do have a tap in the oil line but never use it .

i think some people get a little over anxious about wet sumping when it isnt actually wet sumping to much of a degree and simpy requires a couple minutes at idle before taking off anywhere .

cheers
ian
Groily
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Location: NORMANDIE FRANCE

Re: G11 - Excessive oil in the sump

Post by Groily »

I think somewhere in FW Neill's book it says there should normally be about 8, maybe 10, fl oz in there on a twin, so say half a pint. Not a problem.
melsajs
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Joined: Fri Jan 01, 1999 12:00 am
Location: NORTHUMBERLAND UK

Re: G11 - Excessive oil in the sump

Post by melsajs »

Thanks for all the responses - maybe I'm worrying over nothing
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