Valve oiling

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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Tazmantic
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Valve oiling

Post by Tazmantic »

Quick question about valve oiling, when I was first building the bike up I had to take the head off to fix a stripped thread so I checked the valve oil ways, exhaust was blocked so I cleared it inlet was fine.

So after a few good runs etc and being told it seems to go well with no smoke from the exhaust I just thought I’d check the inlet oil screw and found it was over a full turn out (I believe it should be 1/8th) so with the bike running I removed the screw and expected oil to come out but nothing, so I used an oil can and pumped oil in the hole still no smoke from the exhaust. The only way I could get a small amount of smoke was to pump oil in the hole and then use an air line….. so does this sound like the oil way is blocked because I’ve read other posts where if the screw is out a bit far it smokes lots 🤷???

Thanks
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SPRIDDLER
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Re: Valve oiling

Post by SPRIDDLER »

Tazmantic wrote: Tue Aug 30, 2022 10:36 pm I had to take the head off to fix a stripped thread so I checked the valve oil ways, exhaust was blocked so I cleared it inlet was fine.
Did you check the inlet valve oilways with the the inlet valve removed?
There is a hole in the valve guide that must be aligned with the drilling in the head.

Oiling. Cyl head. 2.jpg
with the bike running I removed the screw and expected oil to come out but nothing, so I used an oil can and pumped oil in the hole still no smoke from the exhaust.
Oil to the inlet valve isn't pumped but is oil that has pooled on top of the cylinder head. When the piston descends on the inlet stroke the low pressure in the combustion chamber draws oil from the oil pool to the inlet valve guide through an open drilling in the head (ringed in the photo below) via the regulating needle. If you remove the regulating needle and pump oil in (or use an air line) it will take the easiest path which is upward via the drilling into the pool of oil in the cyl head and not be forced into the valve guide.
Oilway. Inlet valve. 2.jpg
Having the needle an eighth open is o.k. The Owners Manual will say that if the inlet valve squeaks then open it a bit more.

There's more that can be said but have a look at the photos which may help you to understand the oiling process.
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Tazmantic
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Location: Oxfordshire UK

Re: Valve oiling

Post by Tazmantic »

Thanks Spriddler, yes I made sure oil (used wd40 as I could squirt it) went along oilway and out valve when head was off and after I wrote my post I did think it would be the inlet action that would draw the oil in it’s just as mine is over a full turn out I would expect it to be smoking a bit so was worried it might not be oiling ok but there doesn’t appear to be any squeaks.

Cheers
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SPRIDDLER
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Re: Valve oiling

Post by SPRIDDLER »

Can't help much more except to remove the rockers cover plate with the engine running to check that oil is pooling on the head at the vertical feed drilling.
Presumably you have the correct pointed regulating needle fitted and and someone hasn't stuck a random bolt in there. You did say the bike's a bit of a lash-up. (Ahem, sorry, a 'Special').

inlet valve oil dims 009 (840x630).jpg
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Last edited by SPRIDDLER on Wed Aug 31, 2022 6:30 pm, edited 1 time in total.
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Joker_Bones
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Re: Valve oiling

Post by Joker_Bones »

I no idea at what rate the oil is supplied, but I would be puzzled as to why no oil came out of the hole with the adjuster screw removed. I noticed recently oil was weeping out around the screw on my "special"
Tazmantic
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Re: Valve oiling

Post by Tazmantic »

Hiya yes has the proper screw so next job will be to remove cover and make sure the oil is getting up there.

Thanks again
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clive
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Re: Valve oiling

Post by clive »

Neil i would go with Spriddler that you may be worrying too much. At one Jampot rally i noticed that the adjusting screw had fallen out, just a bit of a weep of oil. I whittled a stick to fill the hole and rode 200 miles home with 3 kids and camping gear in the double adult sidecar. No smoking and no apparent damage.
clive
if it ain't broke don't fix
Tazmantic
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Re: Valve oiling

Post by Tazmantic »

Cheers guys will have more of a look when I get time.

:thumbup:
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