Re: Magneto Auto Advance!

Kevin - nobody else has picked this up so I'll have a go...

The springs should have some tension at rest - or else there's no way it can retard. I've never tested mine but it shouldn't reach full advance until roughly 3000rpm - maybe it could be mounted on a suitable electric drill and flash photographed? Phone flash would be no use to freeze action but 'proper' camera flash is fast enough.

My suspicion is the springs. If everything is free to move, there's nothing else to go wrong. Unless of course something (like the weights!) is missing.

Can you post a photo - are do you have others and know exactly that it is all there?

It isn't one for the opposite rotation, is it? I have a spare unit but it 'advances' the wrong way for a Norton!

If you lock at full advance you'll break your Achilles tendon...seen that happen once...

OOPS wrong one shown...Les

Funny - looks totally different from mine...

Kevin: You mention that your auto-advance had been welded closed and then opened. It could be thatwelding has caused some distortion that is causing the problem. Just a possibility as the metal isn't that thick and the tolerances are quite small so depending on the type of welding, (gas or electric) the heat couldhave caused some distortion

John

Hello On a Norton twin the Magneto should never get that hot only warm you should be able to put your hand on the mag body after a long run and still not be hot so it will burn you having said this I had both my ATDs centre bolts come out went they should not have the bob weights should move freely and spring tension shouldcome in about half way to fully open the ATD is set in fully retard when the engine is stopped so when the engine is runningit then opens with the rpm as you may know so if it's not opening then something is catching somewhere so you may need a set of needle files to file off any obstruction there may be in there orsome how the pivotpins that hold the bob weights in place have come distorted this may be the cause of your problem I do hope you find this problem out or look out for another ATD in good condition yours annaj

Previously kevin_wood wrote:

I'm having trouble with the auto advance not retarding it's self properly. I spent all day fiddling with it yesterday. New chain nice and slack, fitted new springs etc. Moves free enough?

Only rhin hind I can think, the springs are slack/ish at rest/retard. A little tension would be nice. Could this just be poor quality springs?

The unit has been welded shut at some stage and opened back up!

Has anyone had a similar experience?

Would it it be worth putting the mag to manual and what would I need to do it? Slip ring, back points housing, cable and leaver?

Driving me mental! New units are made of rocking horse, by all accounts!

Shes a good mag. Had to bits and done the seal and checked the bearings and repacked with grease last year! Works well when stinking hot too, and that's what matters! Just get the timing on side and we are winning!

Locking at full advance might be an idea at the minute!

Kevin

Hi Kevin, I wrote about this problem some time ago on this forum, before you take the adv/ret device of just check one thing, with the timing cover off and the device not returned to full retard position, ease the engine over on the kickstart and see if that brings the full retard position back, I had a similar problem with my dommi some time ago and I gave it some thought, the design of the a/r unit is such that what you are seeing is the springs of the a/r device are trying to drive the engine forward !, not possible, but when the engine is rotated as in trying to start on the kickstart,the device will return to retard before the mag turns, so there is not a problem, worth a try you think,post the result please be tore you clear off on your ride ,

Regards Jim Hill

Previously David Cooper wrote:

Kevin - nobody else has picked this up so I'll have a go...

The springs should have some tension at rest - or else there's no way it can retard. I've never tested mine but it shouldn't reach full advance until roughly 3000rpm - maybe it could be mounted on a suitable electric drill and flash photographed? Phone flash would be no use to freeze action but 'proper' camera flash is fast enough.

My suspicion is the springs. If everything is free to move, there's nothing else to go wrong. Unless of course something (like the weights!) is missing.

Can you post a photo - are do you have others and know exactly that it is all there?

It isn't one for the opposite rotation, is it? I have a spare unit but it 'advances' the wrong way for a Norton!

If you lock at full advance you'll break your Achilles tendon...seen that happen once...

David , see my comment at the end of this thread,as long as the springs are able to control the bobweights the a/r device will revert to retarded position.