1957 M16 not running properly

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Plugsnpoints
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

Mick D wrote:Hi Andrew

You say you have an alternator late 57 engine

If you check the 58 parts list in the archive you will see:
CB Parts.png
If you need more detail, go to page G3 in the Lucas Complete list:
Lucas CB.png
Regards Mick
Thanks Mick. I feel I am getting warmer now in finding the bits needed :)
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clanger9
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Re: 1957 M16 not running properly

Post by clanger9 »

It's unusual for an A/R fault to have such a big effect. Well done for tracking it down!
Would be interesting to know what's wrong with it...
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clive
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Re: 1957 M16 not running properly

Post by clive »

alanengineer wrote:Are you setting the timing with the bobweights in their relaxed position or jammed open with lollypop sticks. I use the old wooden pegs. Made for the job
Before you decide the AR unit is not working I am interested by your report. Jam the AR fully advanced and it starts easily? Suggests to me the timing is retarded. Normally you would need to retard for an easy start (which is what the AR unit does for you) As Alan asks above are you setting the timing with the AR unit fully advance (ie jammed open).
Can you run the bike, without the lollipop sticks but with the cover off and see if the AR unit opens when you increase the revs even if it is popping and banging. If they are opening then the timing rather than the AR unit is the problem.
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if it ain't broke don't fix
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ajscomboman
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Re: 1957 M16 not running properly

Post by ajscomboman »

clive wrote:
alanengineer wrote:Are you setting the timing with the bobweights in their relaxed position or jammed open with lollypop sticks. I use the old wooden pegs. Made for the job
Before you decide the AR unit is not working I am interested by your report. Jam the AR fully advanced and it starts easily? Suggests to me the timing is retarded. Normally you would need to retard for an easy start (which is what the AR unit does for you) As Alan asks above are you setting the timing with the AR unit fully advance (ie jammed open).
Can you run the bike, without the lollipop sticks but with the cover off and see if the AR unit opens when you increase the revs even if it is popping and banging. If they are opening then the timing rather than the AR unit is the problem.
I'm with Clive on this one. I'd be interested to hear the way you set and check the timing.
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

Hi again. I really appreciate all of your advice with this.

I firstly set the advance retard so the bobweights lined up with the screw holes on the case at TDC (compression) as the manual states.

I then wedged the bobweights fully open, then set the points to open at 1/2" BTDC with a fag paper.


Prior to this I fitted the correct needle/main jets and blew the carb out yet again and set the mixture and tickover by ear. I had already replaced the float and needle plus seat with new items.


It still wouldn't pick up with the throttle opened up.


Then I wedged the advance retard bobweights fully open again and replaced the points baseplate.


It then fired up and ran well (ish).



I then took the point assembly off and found the 'wedges' had flown out and lying in the case.


So I put it all back together minus wedges and tried it. It worked well, but not quite right.


My next step was to get it running and slowly rotate the points plate clockwise to advance it a little at at time until it ran cleanly on tick over and on throttle.


So I put my lid and gloves on and rode it round the block.


It still stutters only a little but it pulls well and revs without missing.


Although the advance/retard unit is worn it looks like you are right, it might have been me. I have learned a lot in the past few weeks! I know I keep saying it, but it's a long time since I have worked on an old British piece of engineering.


I feel I have made a lot of progress now. It's a joy to ride. :)


Thanks again
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clanger9
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Re: 1957 M16 not running properly

Post by clanger9 »

Sounds good - setting the timing by ear (i.e. advance it until it stumbles then retard slightly) will often give better results than setting it “by the book”. There's no guarantee that the factory timing is still right for modern fuel and a possibly undetermined compression ratio...
1989 Moto Morini Dart 350
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clive
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Re: 1957 M16 not running properly

Post by clive »

Bit modern for me these bikes with coils so i cannot comment on your procedure! :rofl: . It does sound like you have done a thorough job though. Except no mention of checking the points gap when fully open. Normally this needs to be done before setting the timing.
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

Hi Clive-I forgot that bit! I did check the points gap is 15 thou fully open before I did the rest of it :)
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Re: 1957 M16 not running properly

Post by 56G80S »

IKBA about the alternator models but thought that the gap on my SR1 should be 12 thou. If originally I set up with 12 thou, making a larger gap would advance, smaller gap retard. That same principle would work for alternator ignition as well? Not that I do that.

Johnny B
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

According to the manuals the points gap is 14-16 thou with coil ignition.

It's the same points gap as a B Series BMC car engine-stuff I can't forget despite my mum's Morris Travellers and Riley 1.5 long gone :rofl:


I am very happy that my bike is running on all cylinder now! :D
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