twin oil circulation

Information relating to the Matchless G11 or AJS Model 30 600cc twin
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ajscomboman
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Re: twin oil circulation

Post by ajscomboman »

600 has a larger inlet valve compared to the exhaust and is quite obvious. The 500 has valves which are almost the same size.
ajsph
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Re: twin oil circulation

Post by ajsph »

The recess in the cylinder head, for the spigot on the cylinder, is 76mm on the 600 head I can not remember the correct dimension for the 500 head but I think it is about 70mm
Best regards
Poul
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dave16mct
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Re: twin oil circulation

Post by dave16mct »

Spigot size on 500cc changed: up to '55 72.8mm, '56-'59 76mm, '60 0n 77.34mm. Excuse my measuring, bit difficult with all the crud in the recesses. So I think you'd be better to go by valve sizes. What size are your valves?
Cheers Dave.
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clive
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Re: twin oil circulation

Post by clive »

thanks Dave. out and about today will reply with meaurements later (although mine will be in inches because thats what the guage works in!)
clive
if it ain't broke don't fix
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clive
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Re: twin oil circulation

Post by clive »

I think the exhaust valve is standard, the "bore" of the valve seat is 1.175in (29.84mm). The inlet valve is I think standard size but the "bore" of the valve seat is I have been told one year only (however the parts list shows same head numbers for 57 and 58 but different to 56), it is pretty thin and perhaps why it rotated. Inlet "bore" of valve seat is 1.360in (34.54mm) whilst the diameter of the inlet valve head is 1.528in (38.81mm). Interestingly I have been looking at the 1958 comp parts list to compare with the 1958 standard parts list to see what was "special" for the 1958 G11CS as opposed to the touring G11. The supplementary parts list shows no differences for the valves but a different piston. However it also lists a different rocker box cover number for the CS rather than the touring G11 or G9. Anyone any idea what this difference might be?
clive
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clive
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Re: twin oil circulation

Post by clive »

Well the good news is that my G11CS is back on the road again thanks to the magic hands of the West London section engineering wizard. The inlet valve seat was rotated back to the correct position and then pinned to prevent it moving again. A run down to Somerset and back at 65 to 70mph was successful so next stop the Alternative.
clive
if it ain't broke don't fix
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clive
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Re: twin oil circulation

Post by clive »

Well it seems I have never sorted out the carb at tickover. Whenever I tootle round town the spark plugs soot up, within 6 miles or so. Travel at speed and all seems ok. I currently have the pilot adjuster out about 2 and 1/2 turns and it seems still to run rich. In fact after taking it off and checking it (checked and replaced pilot jet-size 30, replaced paper gasket ) I put it back on without the pilot adjuster fitted and it seem to run well on tickover.

I have an air filter fitted and have gone down from 280 to 270 on the main jet do I need to reduce the pilot jet to 25? or is it more likely the float level is wrong? Anyone with experience of fitting an air filter to a G11CS? :headbang: Thanks
clive
if it ain't broke don't fix
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saltbox alf
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Re: twin oil circulation

Post by saltbox alf »

Clive , does not the pilot screw increase the flow of petrol as you wind it out?
Hope I am not teaching egg sucking!!
Allons-y, amis de Matchless et AJS
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Re: twin oil circulation

Post by SPRIDDLER »

saltbox alf wrote:Clive , does not the pilot screw increase the flow of petrol as you wind it out?
Hope I am not teaching egg sucking!!
Tchh! Alan. It's an air regulator. The further out it's screwed the weaker the pilot supply.
In words you'll understand it's just like wine bottle cork - the more it's out the weaker you'll feel; the more it's in the richer you'll be. ;)
'There is a tide in the affairs of men
Which taken at the flood............'
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saltbox alf
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Re: twin oil circulation

Post by saltbox alf »

What am I on about. sorry :oops:
I was thinking of something compleatly different and my fingers just went off on their own!!
Then perhaps it's pilot jet size as normally it would be 1 1/8 to 1 1/2 turns for aprox set up. 2 1/2 seems a bit much .
Allons-y, amis de Matchless et AJS
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