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1955 Bullet
Posted: Tue Aug 07, 2012 10:45 pm
by layfin
Hi All.
I have a 1955 350cc Bullet which will start reasonably ok when cold, however when hot it is virtually impossible to start.I would appreciate any suggestions on how to solve the problem.
Regards.
Chris.
1955 Bullet
Posted: Tue Aug 07, 2012 11:10 pm
by Norm
Magneto? Hot magnetos can cause problems
1955 Bullet alternative to rebuild?
Posted: Wed Aug 08, 2012 6:54 am
by Mark M
Yep, as Norm says, classic symptoms of capacitor failure inside the magneto, rebuild required. However, I recently came across mention of a cheaper alternative to a full rebuild but haven't had time to investigate fully. Have a look at the Brightspark Magnetos website, this could be the answer to a lot of problems!
REgards, Mark
1955 Bullet
Posted: Wed Aug 08, 2012 10:33 am
by Anders F. R.
This is just like the magneto on my 1953 Model G was before i had it rebuilt. What happens after 50 years or so is that the shellac or whatever they used as insulation on the windings is cracking. When hot the metal expands and the cracks open, leaving uninsulated gaps. Then you get short circuits and no spark. When it has cooled down it may work fine for a while again. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
I got a very educational demonstration of this when I handed my magneto over to the workshop. He put it in a test bench, hooked it up to an electric motor and ran it at about 1500 rpm. It sparked happily away across a 6 mm spark gap. Then, as it was running, he heated the magneto body with a heat gun, and suddenly it started failing, first intermittently, then completely. At that point it was just not too hot to put your hand on it. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
I think the only real and permanent solution to this is a complete rewinding and rebuild. There may be other ways, but it will have to come apart anyway, and I doubt that it will be much cheaper to do it "almost" than completely. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
Good luck! Regards, Anders F. R.
1955 Bullet
Posted: Wed Aug 08, 2012 11:52 am
by layfin
Many thanks for your help. Any suggestions as to the best place to have it repaired.
Regards.
Chris.
1955 Bullet
Posted: Wed Aug 08, 2012 12:13 pm
by Mark M
I can recommend Dave Fisher, Moathouse Magnetos on 01929 421255. He's just done the mag on my 1955 350 which I'm rebuilding for a series of articles in The Royal Enfield Magazine, find it online at greenlane.biz REgards, Mark
1955 Bullet
Posted: Sat Aug 11, 2012 10:13 am
by layfin
Thanks for all your advice.
1955 Bullet
Posted: Sat Aug 11, 2012 10:13 am
by layfin
Thanks for all your advice.
1955 Bullet
Posted: Sat Aug 11, 2012 10:14 am
by layfin
Thanks for all your advice.