Strange

Information relating to the Matchless G12 or AJS Model 31 650cc twin
SPRIDDLER
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Joined: Wed Sep 01, 2004 1:00 am
Location: WEST SUSSEX UK

Re: Strange

Post by SPRIDDLER »

AGoodfellow wrote: the problem is i now cannot run the engine with the choke off. When i do it miss fires, as if there is a very weak mixture. so in turn i am having to run it with the choke slightly on about 1/4 choke.
Thinking 'off the wall' and from my experience that very many carb problems turn out to be electrical and vice-versa (e.g. Corky's non slow-running tickover), could it be that when you refitted the carb or tank you partly dislodged an electrical connection or that the choke cable runs too close to and shorts an H.T. lead? That is to say that when the choke cable's tensioned it flexes just enough to make the fault disappear.
Worth a look.

(O.K. O.K. you lot, chortling in your armchairs with a large glass of St Emilion; stranger things have happened...............and I'm bored and on call for family taxi duty)
'There is a tide in the affairs of men
Which taken at the flood............'
JimFitz
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Joined: Thu Feb 27, 2014 9:27 am
Location: Kent, England

Re: Strange

Post by JimFitz »

[quote="AGoodfellow"stripped the carb and inlet manfold off machined the surfaces flat, sealed them with gasket silicone.
[/quote]

Trouble is that although the inlet manifold faces may be flat relative to each other there is no guarantee that the corresponding faces on the heads are flat hence the factory advice to tighten the manifold before the heads.

Jim
Too old to Rock and Roll but too young to die.

1952 G80 rigid, 1960 G12 DL / Watsonian Monza, 1954 G80S.
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AGoodfellow
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Location: ANGUS UK

Re: Strange

Post by AGoodfellow »

Guys,

Thanks again, Jim i rigged up a pressure test on the inlet manifold and did a pressure and vacuum test both came out with no leaks. ace...
I have just replaced the plug leads and coil(which was new) and also removed the two fuel taps. the original filters inside the tanks had bits inside so i have unsoldered them cleaned and resoldered them up.

Anyway, i'm not sure what was causing the problem but i went out on the bike today and it was fine and back to normal. so either the fuel filters in the tank or the coil or the leads..

Anyway, may i say thank you for all the help and comments on getting the bike back to where it was and running well.

Andrew
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Merlin
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Location: BLACKPOOL UK

Re: Strange

Post by Merlin »

That's why it is better to do one thing at a time and check then you know what the problem was. Just a thought.
Chemists do it with test tubes
JimFitz
Posts: 663
Joined: Thu Feb 27, 2014 9:27 am
Location: Kent, England

Re: Strange

Post by JimFitz »

AGoodfellow wrote:Guys,

Thanks again, Jim i rigged up a pressure test on the inlet manifold and did a pressure and vacuum test both came out with no leaks. ace...
I have just replaced the plug leads and coil(which was new) and also removed the two fuel taps. the original filters inside the tanks had bits inside so i have unsoldered them cleaned and resoldered them up.

Anyway, i'm not sure what was causing the problem but i went out on the bike today and it was fine and back to normal. so either the fuel filters in the tank or the coil or the leads..

Anyway, may i say thank you for all the help and comments on getting the bike back to where it was and running well.

Andrew
Glad you have sorted it Andrew. I fitted a brand new reproduction Lucas coil to my old Wolseley only to find it was faulty. Lots of sub-standard electrical parts being imported nowadays. I always buy this sort of stuff from the Distributor Doctor (a recommendation not an advert) - a bit more expensive but it always works!

Jim
Too old to Rock and Roll but too young to die.

1952 G80 rigid, 1960 G12 DL / Watsonian Monza, 1954 G80S.
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