Does anyone know where I can get the auto-advance unit reconditioned for my 1956 AJS Model 18, please? It's sticking when it gets hot and the engine runs on and won't idle properly. I think the mechanism is a bit worn and I can't undo it to have a look. The securing collar on the inside (magneto) end refuses to budge. Has the collar got a left-hand thread (not the internal bolt, which I know has), or is it peened on?
I dropped my Matchless G80 on a sharp corner just down the road today and am still a bit shocked. It's the first time in over 40 years that I've fallen off. No serious damage either to the machine or myself, but I ripped the sleeve on my suede jacket, which luckily saved my skin - literally. I think the tyres must be perished (hardened rubber) and need replacing.
Seized A/R's on SR1 mag's have been discussed here over & over again. They will stick if not used. Probably an old worn one may not stick so much.
Basically.....With the AR still on the bike, open and close the unit by hand. If stuck hard this may need more than hands to get it moving. Use a drip tray and plenty of petrol or White spirit, flood the thing while working it by hand. Watch the rust coloured white spirit that comes out. Keep doing this until its free. It should promptly snap shut when its freed off. Spray with WD 40. Grease up the chain a bit and job done. Use the bike or look after it when standing. However, the AR gets overlooked when you splash a bit of oil and grease about. So expect it to rust and seize up. Over the last 30 years I have had to clean my SR 1 AR's several times after a winter lay up of neglect. I have never had to have them apart or replace any parts. If you have not maintained your AR recently, it may have stuck real tight. So will need more than hands to get it moving. The AR will usually stick open, so the bike will be a pig to start, kick back etc and not run well. I had hell of a job to get one free 10/15 years ago. It needed a good flooding of penatrol and levers to get free until I could work it by hand and clean it out.
Yes, all good advice, Rob; but I've done all the things that you have suggested. I've cleaned it thoroughly until there is no rust left in the unit and is lubed to the hilt, even placing it in an oil bath for 24 hours! I regularly service the unit and the thing moves freely all right and snaps back okay. The problem only occurs after running for a while until it gets hot, therefore it must tighten up on the shaft, which I suspect is worn a bit. Dunno...
Do you remember the video I put on the forum some months ago of the Ajay running at an over-fast tickover, when you (rightly) suggested it might be the ATD unit at fault then? (It settled down to a steady thump thump after placing a finger over one of the carb ports!)
It could be the wrong springs fitted to the unit and they need to be a bit stronger to overcome the slight resistance. The club supplied them back along.
eemm, I have never had an AR stick for any other reason than the rust problem causing them to seize. Then only in the last 30 odd years when I only used the bike for pleasure. No problems at all back in the 50's & 60's. Never ever even replaced springs. Fast running must be due to carb or air leak.
it will be interesting to hear the outcome of what is faulty with the AR, and if it solves the problem. The things can be tricky to fit, so I wonder if internal damage has happened fitting it. Cross threaded ???? that may alter alignment causing it to jam.
When I undid first undid the securing bolt, I noticed it was scored across the shank, so I replaced it with a new one. Obviously, it would appear that internal damage to the unit has occurred at sometime in the past. Not under my tenure, I might say! Hmmm...we'll see.
