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[Hugh]

For those who picked up my earlier posts it was the magneto that was gone. It has now been repaired and refurbished and needs refitting.The bike is 1957 Redditch. I understand that the process from compiling various internet sources is as follows.

Set engine to TDC - 1/2 to 7/16 inches pre TDC on compression stroke (350 cc engine)
Refit magneto with relevant 3 screws through timing cover and gasket. Set points gap at .015 though have been told this was done by the service centre when magneto repaired but will be checked.
Set auto advance mechanism to maximum advance by rotation of 2 halves against springs and hold in position with appropriate wire tie
Insert thin paper (e.g.Rizla) between points and turn the magneto until paper can just be pulled out. My magneto is anticlockwise so is the done on timing cover side and move magneto shaft anticlockwise as I presume this will open points? I understand on no account must cam be disturbed from its position as magneto efficiency will be affected. I don;t want to do anything which will create this problem.
Put auto advance on magneto shaft and tighten auto advance nut clockwise pulling it onto magneto shaft (I only have a bolt (no screw which may be on later models) through auto advance as per 1957 parts book). How do I stop magneto turning as I tighten since am presuming this would undo my points setting earlier or will auto advance unit teeth being engaged in idle pinions etc and maybe bike in gear prevent this?
Once all tight recheck points gap.
If all OK above re-attach timing cover and proceed to restart bike and drive away (here being very optimistic that have done things right) .

Any comments appreciated as normal as first time done job so learning from very limited basic skills. Many thanks as normal Hugh


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[Beezabryan]

I use .002 feeler gauge, better than flimsy tearing fag paper.

[Rushour]

I agree with Bryan - although there are those that say fag paper is only 1 thou thick - I have my doubts and use feeler gauge, I would bolt the A/A unit on the mag and time it by removing one of the intermediate gears - time up and fit gear when in the correct position.

[Bullet Whisperer]

The teeth on the intermediate gears give increments of 18 degrees at the crank, so unless you are 18, 36 or whatever other multiple of 18 degrees out on the timing, you are not going to time it bang on by moving them to fine adjust.

[Adrian]

I had a quick look at Pete Snidal's Bullet manual which does briefly cover the Redditch models fitted with manual advance magdynos as well as the auto-advance SR1s.He suggests timing the SR1 with the auto advance at the fully-retarded position, i.e. with the thing "at rest" and the piston at 1/32" before top dead centre on the firing stroke.

If you're really flush you can buy specialist magneto timing light kits from The Magneto Guys for about £40.

Using a screwdriver in the cam fixing screw slot just to hold the armature in position while you fasten the auto-advance unit shouldn't cause the points cam to become dislodged, just nip up the auto-advance end with a relevant spanner, then when it's properly sat on the taper you can grip the auto-advance pinion and tighten the nut on the armature against that.. If whoever overhauled your magneto put it all back together properly you should be fine.

Don't forget that if you've had the timing cover off you'll probably want to re-fill the timing chest before starting the bike, or at least squirt a good dollop of oil around the cams before the timing cover goes back on.

As a matter of interest, who did you use for the overhaul? We appreciate recommendations for that sort of thing.

A.

[Bullet Whisperer]

I ALWAYS time any machines, RE or otherwise to full advance. This will eliminate any over advancing due to any wear which might be present in what are often old A/R units if timed to the retarded settings. It is better to start and tick over a couple of degrees too retarded than pull flat out with too much advance. Also, some electronic ignitions I have worked with don't have as much range as the mechanical ones had - another reason to time fully advanced!

[Hugh]

Will try to re-install by end of week. Thanks for all advice. When up and running will give feedback on magneto and its repair for others to consider using. Found the individual (an ex Lucas employee) very helpful and very knowledgeable. The name was given through a previous post and certainly saved me some cost against those who post in classic bike mags. Thanks again for the comments and hears hoping for a good summer. Hugh