Pete Ashby Posted September 9, 2018 Share Posted September 9, 2018 (edited) I thought this was the best place to post this request as you chaps on this forum board will have more experience of Magneto ignition systems with your age of trucks. I have a Simms SRM4 rubber coupling non inertia 4 cylinder mag that is in very good physical condition but delivers a weak/intermittent spark at the plugs so I suspect there's either a problem with the condenser/ winding's/magnets/carbon pencil so I'm looking for a good reliable company to service/repair the unit. I've had a look on the web and have seen several firms who do this sort of thing but I would be interested to hear recommendations from anyone here who has had a magneto serviced recently, quality of work, ball park price for work done and turn round time would be of interest. Many thanks Pete Edited September 10, 2018 by Pete Ashby Quote Link to comment Share on other sites More sharing options...
mogmaner Posted September 9, 2018 Share Posted September 9, 2018 Check your plug gap ,It needs to be around .0010 inch for non mags. Quote Link to comment Share on other sites More sharing options...
Pete Ashby Posted September 9, 2018 Author Share Posted September 9, 2018 (edited) 15 hours ago, mogmaner said: Check your plug gap ,It needs to be around .0010 inch for non mags. Thanks for this, however I'm happy the plugs are set correctly and they are the correct multi electrode type as specified by Simms for mag operation, they are set at the specified gaps so I'm fairly certain it's the Mag at fault as all the HT leads are new copper cored and have very low resistance values so I don't think it's a HT lead issue either. Pete Edited September 10, 2018 by Pete Ashby Quote Link to comment Share on other sites More sharing options...
Nick Johns Posted September 9, 2018 Share Posted September 9, 2018 (edited) Magnetos can be very troublesome, my Brother has had several Lucas mags rebuilt/rewound by "Specialists" for His Bullnose Morrises one was an NOS mag and all failed after a short time, mind you they were Lucas mags, a Sims mag will no doubt be better made. He has now made a coil ignition conversion that still retains the magneto as a distributor to keep the original appearance and uses an external conventional 12v ignition coil, since then has had no more problems Edited September 9, 2018 by Nick Johns 1 Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 10, 2018 Share Posted September 10, 2018 17 hours ago, Pete Ashby said: I have a Simms SRM4 rubber coupling non inertia 4 cylinder mag that is in very good physical condition but delivers a weak/intermittent spark at the plugs so I suspect there's either a problem with the condenser/ winding's/magnets/carbon pencil so I'm looking for a good reliable company to service/repair the unit. You could try an in-distributor condensor replacement before committing to a rebuild. http://www.brightsparkmagnetos.com/easycap/index.htm Personally I don't like to see magnetos converted to coil ignition. A magneto in good condition provides an excellent spark and they are very reliable. 1 Quote Link to comment Share on other sites More sharing options...
Tony B Posted September 10, 2018 Share Posted September 10, 2018 Useful, thanks! The Coventry pump engine magneto I have is being acomplete Lucas of a thing! Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 10, 2018 Share Posted September 10, 2018 1 hour ago, Tony B said: Useful, thanks! The Coventry pump engine magneto I have is being acomplete Lucas of a thing! Hmm... Does it look anything like this: https://photos.app.goo.gl/GpMFXVvH2ZV5B5cX7 (I think that is a barn-find, I found it in my dad's barn) Quote Link to comment Share on other sites More sharing options...
Tony B Posted September 11, 2018 Share Posted September 11, 2018 Yes it do. A small four cylinder side valve. If you have the exahust manifold still does it have a box with a vavlve in it under the the Y? That was used to generate vacum to prime punp. Quote Link to comment Share on other sites More sharing options...
Slurr Posted September 11, 2018 Share Posted September 11, 2018 Found this in the Guy FBAX manual, hope the tips can help you with your magneto David 1 Quote Link to comment Share on other sites More sharing options...
Slurr Posted September 11, 2018 Share Posted September 11, 2018 I came across this outfit which looks like they do a pretty good job and know what they are doing. They are based near Eastbourne on the south coast of England. http://www.themagnetoguys.co.uk/ Cheers, David 1 Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 11, 2018 Share Posted September 11, 2018 5 hours ago, Tony B said: Yes it do. A small four cylinder side valve. If you have the exahust manifold still does it have a box with a vavlve in it under the the Y? That was used to generate vacum to prime punp. Yes, there appears to be such a box. It was given to my dad as being from a fire pump. Free to a Good Home, as they say. Quote Link to comment Share on other sites More sharing options...
Tony B Posted September 12, 2018 Share Posted September 12, 2018 (edited) Slur you total Diamond! Thanks a lot just what's needed! Andy, if no one else wants it , give me a chance to get back to you will you? Very busy over this weekend. Edited September 12, 2018 by Tony B Quote Link to comment Share on other sites More sharing options...
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