Plug/Points gap ?
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John S Bradley
- Posts: 8
- Joined: Tue Dec 27, 2016 12:54 pm
Plug/Points gap ?
Since having problems starting I decided to clean the points and the plugs .Regrettably my magneto spanners do not have the setting gauge strip attached,they are probably much older than me, please could someone give me a linear dimension,0.001" or mm , so that I can use feelers?
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Humphrey47
- Posts: 38
- Joined: Mon Feb 19, 2018 6:46 pm
Re: Plug/Points gap ?
Try .012" for the magneto
Re: Plug/Points gap ?
Hello John
I agree 12 thou for the magneto but be aware that not all magneto manufacturers were singing from the same hymn sheet! The majority did specify 12 but a few recommended 15 and I did find an odd one, can't remember which but it was a very early one at 25. Make sure you check the gap on both cam lobes as there is sometimes a noticeable variation. If you find a variation set at 12 minimum. The wrong gap will probably upset the internal timing which is likely to result in no spark at either full advance or full retard.
On plug gaps set at 18 thou. Don't be tempted to go wth the coil ignition settings of 25 thou. The extra voltage needed at 25 tends to over stress the magneto windings leading to short life even with modern winding materials.
Please do let us know how you get on
Regards
Martin
I agree 12 thou for the magneto but be aware that not all magneto manufacturers were singing from the same hymn sheet! The majority did specify 12 but a few recommended 15 and I did find an odd one, can't remember which but it was a very early one at 25. Make sure you check the gap on both cam lobes as there is sometimes a noticeable variation. If you find a variation set at 12 minimum. The wrong gap will probably upset the internal timing which is likely to result in no spark at either full advance or full retard.
On plug gaps set at 18 thou. Don't be tempted to go wth the coil ignition settings of 25 thou. The extra voltage needed at 25 tends to over stress the magneto windings leading to short life even with modern winding materials.
Please do let us know how you get on
Regards
Martin