Some general advice

Steve Dempster · Post by **Steve Dempster** » Wed Oct 24, 2007 9:50 pm

Hi all -

Ok this is another 'I'm a newbie' plea but I am so do please bear with me! After the usual 30-year gap I have again took possession of a two-wheeled millstone in the form of a 1962 G12. This particular beast was in the possession of the last owner since 1974 to now, being stored in a nice dry place since - get this - 1984. It looks generally in excellent nick and is, as far as I can tell, completely original.

I've never had a Matchless, having owned Triumphs and Nortons in bygone days but I do like the look of the G12 and it seems well-engineered and finished. Having dismantled and cleaned the carb (gods what a gooey mess) and remembering too late the very bad move of taking the banjo apart (it now leaks like a sieve) I realised that I haven't the faintest idea of where to get simple things like fibre washers these days! I don't even know which plugs the thing takes! (Lodge? got some funny looks at the local Halfords when I asked re these....) So what IS the modern equivalent? I bought the bike as a non-runner but there seems little wrong with it except it's been stood for a long time. Any particular things to look out for? Compression seems OK and the brute gave a couple of immense pops and bangs when a drop of petrol was introduced via the plug holes but that was prior to the carb clean up and it still seems a bit reluctant to fire up properly. I shall work on it.

Thanks, any suggestions or tipe most gratefully received!

lawrence · Post by **lawrence** » Wed Oct 24, 2007 11:42 pm

Hi Steve
Welcome to the forum. I hope you get as much pleasure from your twin as I have from mine but hopefully with less grief The first recommendation I would make is ‘join the club’. It is full of lots of lots of lovely people who have done everything you are going to but lots of times. Their experience is invaluable. Listen to it and it is hard to go wrong. Alternatively you could be like me and leap into a ‘modernisation’ programme and end up saying “ Er, Alan, you know you told me it would be foolish to……… Well you were right”

Your big question is ‘what is the engine and gearbox like inside’? It sounds wonderful that it has stood unused for twenty-three years but in reality it is a potential disaster unless the bike was prepared correctly for such a long lay-up. My twin sat unused for twenty-five years in a garage until I bought it. I couldn’t decide whether to chance running it or not. The carburettor was solid with fuel residue but having cleaned it up I was tempted to try starting the engine. I am glad I didn’t as the last bit I dismantled (the gearbox bearing behind the sprocket) was solid rust. If I had tried running it the box would have suffered. The engine also had minor rusting inside which would also have caused damage though as every wearing surface had to be replaced/resurfaced I guess that would not have made much difference.

If you think it has been kept well then I would be tempted to replace all the oils (washing out the oil tank best possible with petrol) and fuel, start it and after about a minute stop the engine, drain the oil and see how it comes out. You are taking a gamble doing this. The safe option is to strip everything and check it.

Fibre washers etc can be bought from Jampot Spares. Knowledge will be obtained from the web site and experience. These are beautiful bikes. I have lost count of the bikes I have owned but I love my Ajay like no other. My condolences that you only have a Matchie.

Steve Dempster · Post by **Steve Dempster** » Thu Oct 25, 2007 12:01 am

Thanks for the info - I believe the previous owner purposely 'laid-up' his two bikes (other was an A10) and had them drained etc. I take your point re internals and will be MOST careful! I know the temptation is to roar off into the sunset (and then explode!) but I will try to resist until I'm sure the detonators have been removed!

Steve Dempster · Post by **Steve Dempster** » Thu Oct 25, 2007 12:15 am

Steve Dempster · Post by **Steve Dempster** » Thu Oct 25, 2007 12:16 am

BTW - just to stop me running around in circles - just which modern plug does the G12 take? Had a look on the web but can't find it easily, though it's doubtless on there somewhere....

Biscuit · Post by **Biscuit** » Thu Oct 25, 2007 12:29 am

You could try NGK B6ES or B7ES. Look here http://www.spark-plugs.co.uk/ for equivalents for the original fitting.

Thed original was KLG FE80 for the cooking version and FE220 for the CSR

Steve Dempster · Post by **Steve Dempster** » Thu Oct 25, 2007 12:33 am

Thanks - mine is definitely the kettle version! I used to run 1 grade hotter on my old bikes because I tended to just bumble along (lord knows what I'll be like now!) - is this advisable with these engines do you think?

Steve Dempster · Post by **Steve Dempster** » Thu Oct 25, 2007 10:00 pm

Right - another question. I degunked oils etc - actually not bad at all considering - popped in two new NGK's and after a bit of pogoing on the kickstart off we went - then stopped after a few seconds. Try again - same. I've cleaned the carb out but I'm more familiar with the concentrics than the monoblocs - would there be anything there I may have missed? It almost seems like fuel starvation (I did remove the tank cap just in case). Anyone any ideas? It does sound well when running, though! Thanks

SPRIDDLER · Post by **SPRIDDLER** » Thu Oct 25, 2007 10:58 pm

I assume you cleaned the (nylon) filter at the banjo in the fuel feed ?
Even so, more crud can easily have worked its way from the tank down the fuel line(s) so I'd check the filter again.
Are you closing/opening the choke?
It seems to me that the engine is just running long enough (I assume you really mean only "a few seconds") to use up the post-tickling fuel. Is the float sticking up - i.e needle valve closed? Try disconnecting the fuel pipe from the carb and check that the fuel runs continuously out of the fuel pipe. (- But I guess you know all that from your Triumph and Norton days). From what you say it seems to be leaking continuously so presumably there's no blockage.
Just for the sake of it check the adjustment of the pilot jet - as a guide it needs to be one and a half turns open. (Close it gently and without force or you'll damage its seat). Though if the engine starts I doubt that it needs much adjusting.
If it's been standing a while the plugs could be oiling up with historical gunge - p'raps. I doubt they would both foul together and then clear spontaneously in a short while. Have you had 'em out to check?
It'll go.

Steve Dempster · Post by **Steve Dempster** » Thu Oct 25, 2007 11:12 pm

Thanks Spriddler! I did check the gauze in the banjo and dug out several mutant potatoes along with other more dubious debris. The fuel flows well down the pipes and I have now fixed all leaks. The really odd thing is that the duration of running is growing longer - in fact since my last post I have had it running for several minutes but it seems a bit nervy and pops and spits a bit with the A/R lever about halfway. Anyway I'll check the needle and pilot as suggested. Sounds veeeeery nice when its running, though, and scared the bejasus out of the neighbours cat!