G2 Oil supply

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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G2 Oil supply

Postby sej » Thu Oct 04, 2007 2:48 pm

Hi, Wonder if anyone could help. Finally finished my G2 - started it up with the oil filler cap off to check the flow of oil. The oil level is dropping only slightly and the return hole inside is just showing a small return flow, I switched engine off. I tried taking the felt oil filter out, it was full of oil but no change still only a small return flow. Took the tappet cover off and oil is coming out of the tappet oilers in the head OK. Is there any way of checking the oil is getting around the rest of the engine without stripping it all back down? Is it the case that the level of oil should drop right down while the engine is running even idling?
Thanks for any help

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G2 Oil supply

Postby SPRIDDLER » Thu Oct 04, 2007 6:37 pm

This is a regular topic on here.
Buttock clenching times, the first start-up.
Usually it comes down to the bike not being allowed to run long enough.
I've no direct experience of your model but...
Provided that everything was well oiled on assembly the 'usual' delay has been recorded on here as up to two minutes before the normal flow ( a series of bubbles, burps and weak spurts - not a continuous flow) is apparent. I know two minutes is a lifetime to wait but see what others say here or search on the topic on this forum. Should keep you amused for hours!
Some filters (not sure if this applies to the G2) have been found to be blocking or partly obscuring the return orifice and it has been necessary to trim off excess rolled over felt at the end (s).
I poke badgers with spoons.

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G2 Oil supply

Postby alan » Thu Oct 04, 2007 8:59 pm

hi steve,
you dont get a full flow of oil in a steady stream on the g2, it just glugs out slowly, so i dont think you have anything to worry about.
regards, alan

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G2 Oil supply

Postby chris kelly » Thu Oct 04, 2007 10:23 pm

Hi Steve, Sounds about right with my ex 1966 AJS 14 CSR.

The handbook states, " The normal oil level is 0ne inch below the filler cap orifice, the oil content is 2 and a half pints.Run the engine for a short period to scavenge the sump before "topping up".

I believe, ideally, the felt should be on the inside of the cylindrical metal filter cage. Some I bought three to four years ago were wrapped around the outside and can be "bunchy" at top or bottom. I believe the Club have got the filters with the felt on the inside now.

The oil pump forces oil through...." A, B, C, " If you want me to quote this...then let me know.

The adjustment of oil feed. " The internal flow of oil is controlled by fixed restrictions, with the exception of the oil feed to the inlet valve guide, which is regulated by a needle pointed screw located in the cylinder head and secured by a locknut.To adjust........"

According to some members they do not have this, but my bike did. "An excess of oil to the inlet valve guide will cause a smoky exhaust and heavy oil consumption"

The exhaust valve stem lubrication...drillings etc....."provides positive lubrication for this part of the engine and needs no adjustment".

On my bike, I would say , after its overhaul, that the return was quite a strong spurt, regular but not constant.


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G2 Oil supply

Postby sej » Fri Oct 05, 2007 9:10 am

Hi Spriddler, Alan and Chris, thanks very much for the replies. It certainly makes me feel a lot happier. The felt filter is on the inside of the mesh and I trimmed it after reading the tip. I rebuilt the engine with plenty of oil. I have an oil feed screw to the inlet valve which is half a turn out.
My main worry is after reading that the oil pump outstrips supply I was expecting the holding tank to be nearly empty and all the oil to be travelling around the engine. I have tried running the engine for about three minutes but the oil level only drops slightly. It is returning nicely in a moderate glug.

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G2 Oil supply

Postby Biscuit » Fri Oct 05, 2007 12:00 pm

It isn't 'ideal' to have the cage outside the felt, it is ESSENTIAL. If it was outside, the felt would be pressed against the outlet.

Post war bikes:-
All singles, felt inside the cage.
All twins, felt outside the cage.

As the outlet from the filter chamber on lightweights is part way down the 'ole, trimming is unnecessary.

Mm, no one noticed my boob, ie twins felt outside the cage is only those filters that go in the engine. Pre '56 twins with the older style oil tank with filter, as singles.

Edited by - Biscuit on 05 Oct 2007 10:54:08 PM

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G2 Oil supply

Postby bag-o-nails » Fri Oct 05, 2007 2:39 pm

workshop manual
matchless motor cycles plumbstead

Quote, PAGE 44

Make sure the cap 042062 at the end of the
filter is poisitoned correctly.
if the cap is canted this will Restrict the oil returning to the reservoir
End Quote .

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G2 Oil supply

Postby TommoT » Fri Oct 05, 2007 9:36 pm

You're correct in noticing that the oil level drops only slightly when the engine is running. This is because the scavenge side of the oil pump starts scavenging as soon as there is enough oil to reach the return bore. You seem to expect most of the oil from the tank being pump round the engine and collected in the sump before any scavenge takes place. This is not so, so don't worry on that account. The tip about only topping up after the engine has run for a couple of minutes, is to prevent over filling of the oil tank. During stand still oil will seep past the pump into the sump, leading you to assume, that the oil level is too low. But as soon as the engine is started, the oil collected in the sump will be pumped back to the tank. This is why you often see a healthy continous return flow the first couple of minutes, after which it falls back to squirting and bubbling.

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G2 Oil supply

Postby sej » Sat Oct 06, 2007 1:06 pm

Hi TommoT, Thanks very much for the reply, very useful information, sounds like the engine is getting the oil it needs. Thanks very much everyone for all your help, Best Regards, Steve

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