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B&S Magnetron Ignition Conversion


BillC

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I am considering converting the B&S I/C 10HP, model 243431, cast iron, single cylinder engine in my Simplicity 725 from the original points and condenser to the Magnetron electronic ignition system. I am already aware the flywheel has to be sent to B&S for repolarizing. The concern I have is, in the B&S service manual it states "NOTE: Flywheel must rotate at 350 RPM minimum on engines equipped with Magnetron ignition." This engine uses the old Delco Remy style starter/generator. The question I have is: During starting, does the starter/generator rotate the engine/flywheel greater than or equal to the minimum 350 RPM required for the Magnetron ignition? Has anyone been successful in starting a B&S engine with Magnetron ignition with the old style starter/generator?
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Bill, I'm running a 1989-model 243431 replacement engine in my Big Ten now that has a Magnetron with starter-generator. It was in my B-210 when I bought it over 5 years ago and ran it in that tractor until I upgraded it to a 16HP engine... It starts and runs fine with a starter-generator, but it doesn't fire off immediately. You have to spin the engine over several turns before it will fire... always has been that way. This far north, that demands a strong battery in the winter time -- one of the several reasons why I run Type 51 car batteries in mine...
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Question... Back in the days I was working for a Simplicity dealer, I send one flywheel to B&S to change the polarity. THis was I guess close to 12 years ago and it cost 100 bucks and shipping if I'm remembering right.. Magnatrons use the same coil, Basicaly even if you buy a self contained unit. So, there is no more chance of engine removal with points than with a mag.. Points will last years, start your tractor at lower RPM and are serviceable outside the blower housing... So why would anyone want a magnatron on an S/G motor ? Not kidding, I would really like to know what is gained. Maybe I'm missing something here.. Salthart
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My decision to change from points and condenser to Magnetron ignition is based on economic cost savings and maintainability reasons. The cost to service the points and condensor is $23.36. The cost for the Magnetron electronic ignition is $36.05. The cost to have the flywheel repolarized is free with the exception of shipping the flywheel to B&S. The return shipping is paid for by B&S. In my case, I happen to live in the Milwaukee area and have the option to transport the flywheel to B&S myself. So, the payback period to go to the Magnetron ignition is 1.5 point and condenser changes and the time I spend replacing the points and condensor can be spent otherwise.
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I understand what your saying.. But we have had a 3415 H for 30 years and only 1 set of points....And I replaced those when I built the engine. I would understand on a battery fired Kohler where burning is more of a problem. But once every couple of years I use an emory file to clean these and I re-adjust the gap and thats it.. LOL And I can rope start it if need be...Don't know that I could get enough rpms to start the magnatron.. Good luck what ever you try and do. Salthart
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If you don`t want to mess with points and condensors you could always use a trigger module. There maintenace free and cost around $12 to $15. Jack`s sells them online. RayS
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I uesd trigger modules from Stens.I don't know how they work but they work.Are you sure yhat the flywheel always has to be repolarized?In the Briggs master parts catalogue they specifically show a Magnetron kit to replace the point and condenser kit. By the way all my equipment have car batteries in them.51 and 45 series.Put one of those in and you'll get 350 rpm.My 1965 Gilson with a 12 hp Kohler spins beautifully.
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