Norton commando kickstart problem

tommy666bikes · Sep 8, 2017

Hello all
Hope someone can shed some light on a problem ive got with my 1972 commando 750 roadster , when i set off in first gear the kick start lever falls down , i was told that the layshaft bearing was on its way out and not to use the bike or lots of bad things would happen to the gearbox and most probably to me as well.
I have since replaced the layshaft bearings both sides :cry: :? and the mainshaft bearings along with every the bronze bushes and seals and thought my problem was solved but upon starting up the bike the same issue is happening.
hope someone can help as its driving me nuts
thank you in advance of any help or advice received
regards Tom

NortonMKIIA850 · Sep 8, 2017

I can imagine that this might happen if the layshaft were too tight a fit in the kickstart shaft bush – I replaced that bush on my bike this summer, and was warned it might need reaming. Mine didn't, but maybe yours does? Just a thought ...

tommy666bikes · Sep 8, 2017

Hi thank you for your reply , when I fitted the bush it didn't seem tight so I don't think this is the problem , however when I strip the box again I will be sure to double check
Thank you best wishes Tom

Mike B · Sep 8, 2017

Try installing a new kickstart lever return spring, sometimes that's all it is.
Mike B

tommy666bikes · Sep 8, 2017

Hi Mike the spring seemed to be ok but I will try a new one just to be sure ,thank you for your reply
Best wishes Tom

concours · Sep 8, 2017

My '74 has done this for a long time. (30,000 miles)
Everything in the transmission inspects well, then later rebuilt.

gripper · Sep 8, 2017

Check that the layshaft is not bent. It might only be short but they can be bent. I know from first hand experience. Also insufficient lateral clearance will make the layshaft influence the kickstart shaft.

tommy666bikes · Sep 8, 2017

Hi I'm goin to have to strip the box again so when I do I will check the layshaft to make sure it's true , thank you for your advise and for taking the time to reply
Best wishes Tom

tommy666bikes · Sep 9, 2017

concours said:
My '74 has done this for a long time. (30,000 miles)
Everything in the transmission inspects well, then later rebuilt.

Hi my bike didn't have this symptom until recently gear changes have always been good with no grinding or any other issue,I've used the uprated bearing on the layshaft that is a common mod on commandos so can't understand why the kickstart moves down on acceleration in first gear

eskasteve · Sep 9, 2017

Going from memory here so I may be off base. In 1975 the kick starter on my 72 Combat would flop down like a beaten dog then engage and spring back up and smack the bejezzus out of my right shin. Kick starter pawl had bought the farm. A trip down to Poke's Cycle in Seattle for parts, back home for the repair, and then back on the road. About three hours total. Not sure if this helps but I guess that it doesn't hurt. If I was taking my trans apart I'd change the pawl just as a precaution if nothing else. They're under 20 bucks.

tommy666bikes · Sep 9, 2017

Hi thank you for your reply , I couldn't see anything wrong with the kickstart pawl but when I pull it apart again I'll be sure to check it
Best wishes Tom

ashman · Sep 9, 2017

Have a look at your kick start gear where the kick start pawl sits in the gear as the inside of the gear wears and the pawl on the kick starter doen't stay locked in when moving this happened to me many years ago and had to replace the kick start gear as well as the pawl, it should be a nice sharp edge on the inside of the gear mine was oval from wear, its worth a look at.

Ashley

tommy666bikes · Sep 11, 2017

ashman said:
Have a look at your kick start gear where the kick start pawl sits in the gear as the inside of the gear wears and the pawl on the kick starter doen't stay locked in when moving this happened to me many years ago and had to replace the kick start gear as well as the pawl, it should be a nice sharp edge on the inside of the gear mine was oval from wear, its worth a look at.

Ashley

Hi thank you for your reply , I'll be certain to check this when I take the box to pieces again
Regards Tom

tommy666bikes · Sep 18, 2017

Hello all thank you to the people who took the time to advise on this problem , I think I've found the problem , it was the layshaft bush in the kickstart shaft that was on the tight side so I've eased it off and all seems ok now
Best regards Ian

NortonMKIIA850 · Sep 18, 2017

Glad you found a fix, feedback's always good!

Norton commando kickstart problem

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