Oil tank filter catastrophe - almost

Information relating to the Matchless G9 or AJS Model 20 500cc twin
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REW
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Re: Oil tank filter catastrophe - almost

Post by REW »

Ok, thanks, procedure is clear. Is 25ft lbs right for a 53 500 with 5/16 studs and nuts? Neill quotes 18 but it may be experience dictates as much as 25 perhaps?
Ron

1951 Matchless G3L thumping round the Durham Dales.
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dave16mct
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Re: Oil tank filter catastrophe - almost

Post by dave16mct »

I torque them to 22, and I've never backed off (I used to ride a Triumph!)
Dave.
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Rob Harknett
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Re: Oil tank filter catastrophe - almost

Post by Rob Harknett »

REW wrote:Got 'em. Mind you, it is only recently I have bothered with a torque wrench, "once more with feeling" works wonders :D

Because the repro filter stops short of the threaded neck I think it has been sucked sideways against the oil exit hole, felt then getting sucked in to almost block it. Seems to me if the filter where a bit longer that could not happen.

I know you wash and reuse your filter Rob (both of you!) but in the end, does the filter really do much?
Ron, I have usually had 3 bikes on the road. My favourite 55/G3LS little 36 prewar 250, and a CSR 250 or 650. Just used for pleasure on runs etc total mileage is not much more than 1,000 a year. ( Much less over the last 3 years ) The book says clean filters every 5,000 miles. In the last 30+ years of pleasure riding, the CSR's have not really clocked up enough miles for a filter clean to become due. The little prewar 250 has only done about 10,000 since I have been riding it. I've only cleaned that filter once as far as I recall. I did have blackish sludge in it. The engine was still as found untouched, not even had the head off, so a dirty engine to start with. The 350 having done most miles, the filter has not had much black sludge in it. So, the filters may not appear to do much ????? Now lets go back to 50's / 60's when my 55 /G3LS was my every day transport, 5,0000 miles clocked up in months then, instead of the same number years now. Back in those days the filters always had black sludge to wash out of them. You have to remember fuel then was dirty. After just a few 1,000 miles you had to de coke your engine. The piston would have quite a heavy coating of carbon to scrape off. That is something I have never seen the likes of, using todays fuels.

That's a bit long winded, but, " do the filters do much question ??? " Today you could say, no they do not do much. That is because they do not have so much to do. They would have appeared to do much more back in the 50's. So I believe they are still needed and still suitable, as they will do the job of filtering when called upon to do it. They will need less cleaning and maintaining than they did years ago.
The gauze filter on the flow pipe still has the same job to do. Now these may even be missing? Their job is to filter fluff etc. that may get in the oil, when topping up etc.

You mentioned your filter may had tipped sideways. Perhaps it did. Perhaps it is a bit short or the spring not good enough to hold it upright and firm. Bit difficult to check that. If you have the filter and parts I recall. there is a cup washer on top of the filter that locates in the filter tube. The the spring also locates in the top of the cup washer. Pressure is put on the spring when you screw down the cap keeping the tube upright. Perhaps you could find a piece of wood, make a mark on it for the cap screw depth, then push it down on the spring to the line. You should be able to feel if you are compressing the spring. If you are not, then the spring is not doing the job required of it. ( Filter short or spring no good ? ) Long time since I replaced a filter cap, but I am sure when you start to screw it in, you can feel it has pressure on the spring. So you have to push down on the top of the cap with one finger, when you start to screw it in.
I am sure the old filters had high density compressed Lambs wool filter material, which your repro filter does not seem to have.
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ajscomboman
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Re: Oil tank filter catastrophe - almost

Post by ajscomboman »

I can only speak from my own experience, 30 yrs tinkering, never blown a gasket (well bike anyway) and never broken a stud or had one strip. I do use the deep cylinder head nuts supplied by AMC Classic Spares and torque down to 25lbs.
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Re: Oil tank filter catastrophe - almost

Post by ajsph »

Hi Ron
When I did service on your bike I used 22 lbs, and the pre owner rode a lot of kilometers without problems.
Regards Poul
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REW
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Re: Oil tank filter catastrophe - almost

Post by REW »

Hello Poul! The bike has been running extremely well without issue. I think this head gasket problem is because the new oil filter in the tank moved sideways and blocked the oil outlet. The resulting pressure in the engine has caused the leak I think.

I have now backed off a touch and torqued to 24 ft lbs Rob at which point I felt enough is enough on the small nuts. I will re-torque tomorrow and run it etc. If it leaks then I will fit a new gasket.

Rob (H) - I don't think the spring on top of the relief plate on the filter could ever hold it vertical in the housing in a twin against the much greater oil flow compared with a single. Actually, it shouldn't have to - surely the top of the filter should just sit within the threaded neck and thus be held?
Ron

1951 Matchless G3L thumping round the Durham Dales.
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Rob Harknett
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Re: Oil tank filter catastrophe - almost

Post by Rob Harknett »

Ron are were talking about the same oil tank? see attachment. If so do you have the cap that fits into the filter, and spring that fits in the dish of the cap and screw on cap. This should prevent the filter flopping about in the tank tube. The fittings are no different to single or twin. AMC must have considered this arrangement suitable. Without the cap and spring the filter could flop about. The pressure of the spring stopping this movement. The take up space between the filter and top cap. I do not think the filter will compress at all or even reach the underside top cap.
Ashampoo_Snap_2017.09.24_16h15m16s_002_.png
Club spares do the cap and spring. You should have the same cap and spring in your single to compare spring length in your twin. Filters will flop about without these correct fittings between filter and top cap.
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G15 Roy
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Re: Oil tank filter catastrophe - almost

Post by G15 Roy »

ajscomboman wrote:I can only speak from my own experience, 30 yrs tinkering, never blown a gasket (well bike anyway) and never broken a stud or had one strip. I do use the deep cylinder head nuts supplied by AMC Classic Spares and torque down to 25lbs.
Same here torque them down to the scream on more, i am sure i had to tighten your nuts down once just be before we set of a rally somewhere, :oops:
Roy
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Janet
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Re: Oil tank filter catastrophe - almost

Post by Janet »

G15 Roy wrote:
ajscomboman wrote: i am sure i had to tighten your nuts down once just be before we set of a rally somewhere, :oops:
What you two do.............
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ajscomboman
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Re: Oil tank filter catastrophe - almost

Post by ajscomboman »

Janet wrote:
G15 Roy wrote:
ajscomboman wrote: i am sure i had to tighten your nuts down once just be before we set of a rally somewhere, :oops:
What you two do.............
If only you really knew..... :rofl:
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