vintage briggs engine magneto update

Anonymous-0 · Sep 26, 2013

I have an old Bolens Vers-A-Matic walk behind. It has an old cast iron Briggs 8B engine. I'm in the process of trying to get the engine rebuild but I would like to use the newer Briggs Magnatron coil and get rid of the points and condensor. I was wondering if anyone has done this swap- if it is possible and any pitfalls? Thanks for the help, Phil

JT · Sep 26, 2013

Probably not gonna work, as the magnetron only works on the Briggs 2 legged coil, and I think that one has a 3 legged coil, if memory serves me right.

Jay Phillips · Sep 26, 2013

Phil,

Lots of people upgrade to electronic triggering, where the old, original coil is still used for the spark. I prefer to replace the entire system with a brand new magneto / coil.

I've converted numerous old cast iron (and aluminum) block Briggs engines over to modern electronic coils.

Since the older bolt pattern (for mounting the coil) is different, new mounting slots need to be machined into the new-style coil. Using a milling machine, I mill mounting slots in a new electronic coil.

The older engines have the opposite polarity on the flywheel magnets, and will not allow the new-type coil to fire. So, the flywheel also has to be changed. I always swap to a cast iron version.

Jay

joe csuti · Sep 27, 2013

Goto link below,enter 31-8786 in search,this might work with your eng,orig coil must be in good working order,if coil weak/going bad this unit will not cure a weak/no spark issue,if unit doesn't work with coil you can put on the side,reinstall/connect points/condenser & use to convert a newer point type ign system eng.

I've had good luck with these units converting several newer mod 3-5hp briggs eng with points.
nova

El Toro · Sep 27, 2013

Polish the existing points using some 320 or 400 wet or dry until they're shiny then see if there's fire to your plug. I have points on my old Wards garden tractor I bought new in 1971.
Also check your magnets on the flywheel using a flat blade screwdriver to see if they have strong magnetism. Hal

jeffcat · Sep 29, 2013

Don't forget those little green or gray plastic gizmos that are on fleabay. You cut the wire to the points and wire this little thing in. Do the same as the Magnatrons. You could get them for chainsaws and stuff too. They worked on several engines I had. Part sales places had them and they were point and condenser eliminators or some such.

vintage briggs engine magneto update

Anonymous-0

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JT

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Jay Phillips

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joe csuti

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El Toro

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jeffcat

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