Hi All

After owning my matchless for 3 years I finally got to ride it for the first time on the open road yesterday it was fantastic!

The bike runs very well at low/mid RPM however increasing the revs brings with it poor running/slight misfiring. I have checked / replaced the spark plug, Ignition lead & ignition cap but no real improvements. The bike runs best, when riding, with the retard/advanced lever pulled almost right the way back/open.

I am at a bit of a loss at the moment so any advice would be greatfully received.

Steve

email (option): findingsteveo@hotmail.com

Steve, you seem a little bit vague about the ignition setting. If the adv/ret cable enters your mag at the back nearest the battery, then you have a tight wire advance set up (correct). In which case if the ignition timing is set correctly, the lever should be pulled towards you for full advance after initial start up. It might pay to double check your timing first, before going on to other mag/carb issues. Ron

email (option): ronpier@talk21.com

Sorry for being a little vague, still getting to grips with the bike. ( I am more familiar with slightly more modern machines)
To clarify the bike runs best with a tight wire advance set up but still misfire a little with poor running. Ron would you be kind enough to confirm how I check the timing?

Thank you I advance

Steve

email (option): findingsteveo@hotmail.com

Undo mag pinion. Set advance and retard lever to full advance. Rotate engine to required amount before TDC. Make sure mag points are set at 12 thou, turn mag in direction of rotation until points are just opening "I use a 1.5 thou feeler gauge, when it just pulls from between the points" then put on the pinion and lock up making sure that the points don't turn as you tighten the nut.

Well OK, but before you start removing the mag pinion, I would check it first incase it's already set correctly. You can check it in a few minutes....Retiming it can take a lot longer.
With a suitable rod down the plug hole, mark it at a convenient sighting spot ie top of plug hole, with the piston at TDC. Now remove the rod and mark it again at exactly 7/16" below your first mark. Now turn the engine over with the back wheel bike in top gear to TDC on compression stroke (both valves closed and able to spin both push rods). Adv lever fully towards you for full advance. Now turn the engine backwards about half a stroke, then turn it forwards again carefully until you hit the lower 7/16" mark. At this point the points should be just breaking. I also use a 1.5 thou feeler gauge. If the points are a little bit wider than just breaking, you can get away with retarding your ignition at the lever to save going through the re-timing process.

The whole checking thing is quicker to do than writing about it.

One thing at a time starting with the easiest

Ron

email (option): ronpier@talk21.com

I'd double check the timing advance, some manuals say set it at 1/2" and others say 7/16" I set mine at 7/16" and it seems to hold back a little bit at full advance.

email (option): davmax@ntlworld.com

Thanks gents, I shall check it out and report back.

After this afternoons outing I noticed that introducing just a fraction of chock whilst riding remedied all misfiring and poor running as you may expect tick over was a little faster but it felt like a different bike.

Maybe I am looking at just a mucky carb?

Steve

email (option): findingsteveo@hotmail.com

I'd double check the timing advance, some manuals say set it at 1/2" and others say 7/16" I set mine at 7/16" and it seems to hold back a little bit at full advance. [/quote]

Well I need to check that out Dave. Would that be from say a post war manual when petrol had improved?

Ron

email (option): ronpier@talk21.com

For the G3WO it states 3/8" I think I usually use 1/2" advance.

With the higher octane ratings nowadays it's better to advance a little more, hence my system of timing the engine at TDC at full retard, then you have a bigger range to play with on the adv/ret. lever, but you have to "listen" to the engine!

Cheers,

Lex

email (option): welbike@welbxxx.net

It could well be Ron, the manual I got it from was one on the Jampot Archives one also it may not take into account the cylinder spacer on the base gasket. It was one of those manuals that covered the entire singles range but also covered separately the WD models. Set at 7/16" mine only seems to hit 50 mph and it feels like it's being held back which it shouldn't do as it's all new inside the engine and has the high lift cams.
Dave

email (option): davmax@ntlworld.com

Dave, only 50?? mine gets up to 70, with the high lift cams, and with my clapped out piston prev. engine I hit 78 once!!

But that is on a G3WO, with the bigger exhaust and carby.......

Lex

email (option): welbike@welbxxx.net

Hi all.

Just a brief update so I had a little inspection on the carb last night, all is clean, the main jet is also clean and clear. It's been suggested to me that the needle may need raising a notch? Can I ask for clarification on the function of each of the two adjustment screws on the side of the carb?

Thanks again

Steve

email (option): findingsteveo@hotmail.com

Steve while you are cleaning the carb, There is a tiny hole in the throat of the carb, between the slide and flange. This sometimes gets blocked and might need poking out with a piece of thin wire. You would need to remove the jet block. If you do a search in the box above for user 'Danny DeFazio' there is a full discussion on this subject.

The screw that is at an angle is simply a throttle stop screw to adjust your tickover by pushing the slide up. The one near the flange is your idle mixture screw. Start by screwing it in all the way and back it out 1 1/2 turns, then turn it in or out a bit for the best effect.......Have you not bought a manual?

Ron

email (option): ronpier@talk21.com

Thanks Ron for your detail.

No currently I do not have a manual, it's next on the list...

Steve

email (option): findingsteveo@hotmail.com

You can download them ALL here:

Introduction: http://ajsmatchless.webs.com/christiansarchive.htm

And site: http://archives.jampot.dk/

And for free, but Christian says donations are always welcome!!

Cheers,

Lex

ps, just checked, but it's not working right now, they may be uploading more files, if not right later today, I'll look into it.

email (option): welbike@welbxxx.net

Thanks Lex!

email (option): findingsteveo@hotmail.com

Dave, only 50?? mine gets up to 70, with the high lift cams, and with my clapped out piston prev. engine I hit 78 once!!

But that is on a G3WO, with the bigger exhaust and carby.......

Lex[/quote]
Believe me Lex, if it did 70, I'd be doing 70! That's why I think it's holding back at 7/16" I used to ride my my M20 at 65mph wherever I could, I used to go 25 miles down the motorway with the throttle pinned to the stop every night for months, my Harley regularly sees 110mph which is flat out!
I didn't want to push it too hard as it had only run for a couple of minutes from a full rebuild so I didn't want to go flat out, but it certainly felt like it was holding back at about 50 so I guess I'll re time it to 1/2" I've fitted high lift cams, fitted a 276 that I bored out to match the manifold, thinned down the end of the guides and smoothed out the ports, thrown away the spacer under the barrel and carefully put it together, but I notice that it never kicked me back, even fully advanced

email (option): davmax@ntlworld.com

Mine kicks back once in a while, so if that is an indication, you're running it too retarded.

The files link is the right one, but they are having server problems, it's being looked into at the moment.

Cheers,

Lex

email (option): welbike@welbxxx.net