Hi Guys.Some guidance please if possible. After spending a lot of time and money, my G3L still is bugger (understatement) to kick over and catch. Theres good compression. If I manage to kick it over and start I am knackered. I have had the mag redone etc.

Having met a fellow owner this weekend he suggested it could be the Carb. A friend did the needles, washers and throttle slides for me recently but no real improvement. I wonder if I may need to consider getting a whole replacement if possible. I understand that they may be now starting to make the 275F/1J again (or am I being hopeful). Its also been suggested that I could get the "276" which may do the job.

Thanks in advance Andy.

email (option): phillip.campion@btinternet.com

Andy, I have recently given up on playing with old carbs and even spending a lot of money having them serviced. I am now firing new carbs and they start and ride like new motorcycles. Don’t buy a 275, you need a 276 and it will run much better. Simply call Michael at Surrey Cyles and he will put one in the post to you. JT

email (option): Tinley@btinternet.com

Try this method to start tickle the carb so fuel comes out the top now with the decompressor pulled up kick it over a couple of times then you will have to get it past the compression stage on the kick start by de compssing it just past compression then kick it over you will have to do this every time you come up against a solid kickstart its simpler to do than to write down on here i put a new 276 on one off my bikes took about a minuteto set up hitchcocks will jet it for your bike and will charge around 260 pounds ps try it with no choke

JT is correct. If the carb is at fault, buying a new 276 may well be your best bet. I have just bought one from Hitchcock's (v good service). Phone them and they will go through the spec with you for the WD G3L. All up, its about £340 inc VAT and pp. I nursed an old 276 for years......it worked well in spells! I bought a used 275....likewise, unreliable. You CAN get your old 276 reconditioned and some folks swear this is the way to go....its cheaper. Finally, I presume you have checked all the other culprits for poor starting. Timing? Points? Plug?

I'm going to make a different suggestion. If the carb is capable of dribbling some fuel into the engine it should at least start,how well it will then run is a different matter.All three of the G3l's in my family have badly worn old carbs - But still will start first kick and run well. A decent spark at the right time is absolutely essential,and some compression helps too...
My main point it to recheck the valve timing,my G3l is the only one of the three with the correct cam timing marks that line up and work properly. My brothers one was always difficult to start,but when running went very well,I tried allsorts to cure the poor starting.It has a good spark etc and I suspected the carb,which I changed for a good Concentric just to test.It made no difference. When we got around to checking the valve timing with a degree disc we realised that the inlet cam was retarded, so the piston was actually pushing the mixture back out through the carb.(But not enough to make a different sound or be noticeable in any way)
Setting the valve timing with a degree disc transformed the starting and it still goes well.

If you are Wiltshire way I'll show you how to start it.

Randomly replacing everything you think might be at fault is not the way to go,nor is it the way to learn anything useful.

The Matchless and AJS cams, although identical have different timing marks, as the cams are swapped around. ie the inlet cam on a Matchless becomes the exhaust cam for an AJS because the AJS mag is in front of the cylinder. Fortunately I was aware of this when Ed Abbot sent me some good used AJS cams for my G3. I worked out the correct position from the marks at the back(???) and transferred painted dots to the front. Ron

email (option): ronpier@talk21.com

A lot of information! I agree, its unwise to replace components in hope of resolution. It may help to take a forensic approach. If it has been a complete rebuild of the engine and you have never had it starting and running well, then I would go over everything, check and set up by the book, including those timing marks. Thats kind of fundamental. If that does not work, it indicates a malfunction somewhere, but its pretty easy to check for fuel getting to the plug, the plug sparking and plug sparking well and at the right time. If it has been running and starting decently, then checking over step by step is needed. At £340 for a new carb, its worth checking and for sure getting someone to check over for you before you splash out! Good luck! Been there, done that!

Thanks for the useful guidance Guys. I must admit £340 for a new carb seems a bit drastic. I will do the forensic approach as suggested and then if I have to, bite the bullet and get a new one. If you hear a scream in the distance, its my wallet!

email (option): phillip.campion@btinternet.com

Thats an interesting point Ron, today I looked at the cams that came out of my brothers engine. There are no marks at all on the back of them, just a 1 and a 2 on the face of each wheel. My guess is that they came from a much later engine.A study for a later date when I need them !

A little point for any Matchless engine rebuilders. I recently did a complete strip on my sons G3l, including fitting a new timing side shaft to the crank.The engine is back together and running well,but the top end at least is going to have to come apart again. In conversation with Steve Surbey he mentioned that the new timing side shafts have a grub screw to blank the oilway end off.The originals have a brass plug. The grub screw is NOT tightened when the shaft is supplied.Now I didn't even notice the change from the brass plug,let alone that the screw wasn't tight. So, apart it will come,I'm hoping I can do it by just having the barrel and head off.If I can unwind it a bit and blast it clean/dry with brake cleaner,I can then Loctite the thread and tighten it up.
I realise that people will say I should have checked it,but my eyesight and brain will only focus on exactly what I'm looking for, not anything next to it.I have that awful thing of not seeing things that are right in front of me - Especially loose spanners in a toolbox etc...

There is no big deal with the AMC cams, the numbering is detailed in any handbook.

you can use any AMC single cam in any other AMC engine,at present I have later H cams in a pre war engine to pep it up a little.

I have even used SH cams in a pre war engine with a little help from a grindstone.

As for that grub screw, I think you are in the muck, its at the flywheel end, so unless you have very very small fingers.................

it's flywheels apart.

I did buy some new high lift cams from Steve Surbey for my G3 and had to grind some ally away inside the timing chest to allow for the extra lift. The whole exercise was to dump the badly worn cams that were fitted which I thought was causing my 'clatter'. Turns out the clatter was excessive end float on one of the rocker shafts.

I reverted back to the standard cams that came from Ed Abbot and the H cams are now in my mate Tim's G3L. Ron

email (option): ronpier@talk21.com

Ken sent this info. Ron

email (option): ronpier@talk21.com

I once had an annoying clatter which I thought was the infamous pre-war Matchless piston slap, it turned out to be an overtight valve lift cable, they need a awful lot of slack.

Well Ken, it was going to go one of two ways... Happily with the head, barrel and piston off I could easily get a long shank 3mm hex key into that grubscrew.The bike had only done about 40 miles since I built it with the new shaft,it was 1/2 way to coming right out,so wouldn't have done many more miles. I wound it out as far as I could and squirted it with brake cleaner,dried it with the shop air and screwed it back in with a dab of loctite.I used a long elastic band to hold the conrod out of my way and used the back wheel to turn the crank, just holding the hex key still to tighten it.Not a bad jb in the end,annoying - But better than a sudden stop and £275 for a new bigend.

My 16H was a pig to start and it wouldn't idle well whatever I did. I realised fuel was getting past the float needle when the engine was running and vibrating. I bought a new plastic float and associated needle and it runs well. There was nothing wrong with the old float, it just wasn't as buoyant.

email (option): jeremy@clogmaker.co.uk