Kick back

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
mikeydpippin
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Location: SOMERSET UK

Kick back

Post by mikeydpippin »

This bike is really starting to impress now, all the niggly faults are sorted except one.
When starting ( it takes a few kicks to start) I find that almost every other kick it kicks me back with a vengeance.
Would that be timing?
Mike
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Rob Harknett
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Re: Kick back

Post by Rob Harknett »

What bike?????? have to try and find out. Would the bike have an SR mag? The bike will not start easy if the A/R lever is fully advanced. If SR1 mag. This may have got stuck fully advanced. ( Been answered many times here ) Lets assume you have the SR1 mag. have the timing cover off. Is it stuck open. If you open it up back hand, will it snap back quickly? If its open or wont snap closed quickly. Use some white spirit, and a drip tray, flood the mag. working it by hand. You may see rust coloured white spirit drain out. Keep doing this till it free's up, then give a good spray of WD40 or oil it. Check the points to make sure they are not a mile open. Leave the timing cover off. Now try and start the bike. If OK job done. If not, perhaps timing is too far advanced. I would have been so since the last time it was set.
mikeydpippin
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Re: Kick back

Post by mikeydpippin »

Sorry Rob, 1963 Matchless G80 500 cc alternator coil ignition.
Mike
Reynard24
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Re: Kick back

Post by Reynard24 »

Hi Mike
Book says 1/2" BTDC fully advanced with points gap at 0 .014 - 0.016" but you may find the A/R mechanism is worn and could be over advancing. To check you'll need to remove it from the taper and view from the reverse - there should be two pegs on the bobweights that move inside two circular holes on the back-plate to limit their travel, as they wear they form a flat on the outside edge and this allows them to move further than they should. Mine were half worn away. Only real cure is new bobweights - try Martin Jay the distributor doctor for these.
mikeydpippin
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Re: Kick back

Post by mikeydpippin »

161436B9-77B3-404B-9877-21E3CD38B430.jpeg

Thanks James, do you mean these?
One side of both pegs are shinier than tother.
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Mike
Mick D
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Re: Kick back

Post by Mick D »

Hi

Why not just retard the timing a little and see if that helps?

Regards Mick
Reynard24
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Re: Kick back

Post by Reynard24 »

Pegs look fine Mike, mine had worn half way through and were therefore semi-circular.
Greybeard
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Re: Kick back

Post by Greybeard »

My G80 did that after its winter lay-up. It was just the cam that needed cleaning and regreasing on its shaft as it wasn"t flicking straight back to the fully retarded position. While I was at it i fitted a new pair of springs which has restored serenity. About £3.60 from the spares folk. They were fitted and working in way under 24hrs from placing the order :)

Steve
Reynard24
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Re: Kick back

Post by Reynard24 »

Did you manage to find a cure for the kickback Mike or are you still struggling?
mikeydpippin
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Re: Kick back

Post by mikeydpippin »

Not yet James, i retarded the timing which just made the engine run very erratic, and difficult to start, greased cam, so my next try is to retime, replace plug, points, condensor, and coil.
Clutch is better now, I had to screw adjuster into pushrod and unscrew just a fraction, with very little play less than 1/8” where cable enters gearbox.
So close now.
Mike
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