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CarlH

No Fire 16 HP Briggs Pointless Magnetron

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CarlH

I think I've tried everything and still no spark. I'm getting a roller Sovereign in usable shape for a nephew. First thing is a decent engine. Among the Briggs on the shelf is one with a recent rebuild and looks nice inside. Another is a later model with the pointless ignition (no holes in block for points or cover) and ugly crank/rod. I moved the Magnetron and flywheel from the latter to the former and properly gapped the Magnetron legs at .011". Spec is .010" to .014". Maybe got a faint spark. Any way not enough to run on.

New plug(s), new Magnetron(s), and careful sanding of flywheel. No spark at all. Still maybe a faint spark with old Magnetron. There is magnetism in the flywheel section to trigger the Magnetron. I have no way to measure it but its seems substantial.

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briggsetc

Keep in mind the Magnetron will need a lot more cranking speed than the point set up that will fire at very low speed. I like to hear a healthy snap on a good working Briggs ignition.

The magnetron coil assembly is way simple. If you have the laminations grounded and the small wire NOT grounded it will work or it is bad. With good flywheel magnets,of course,properly gapped as you have already done.

Sounds like you covered all the bases so I think you need to give us all the numbers off both engines to see what you are dealing with and see if there is a compatibility problem.

Could you beg borrow or steal a KNOWN good Magnetron to try??

Gary

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CarlH

Thanks Gary.

I am cranking without a plug installed and a fresh battery so I think RPM is good. No numbers available from either engine. I don't know of anything that would need to be transferred besides flywheel and Magnetron. Is that a valid assumption? I will remount/check Magnetron mount to be sure of a good ground.

I guess this is mostly curiosity since plan B is Kohler style points conversion although nephew would be better off with a pointless ignition system since he has minimal mechanical skills.

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powerking_one

Carl,

Just because you took the flywheel and Magnetron coil off "another" engine doesn't mean the flywheel magnets are the correct polarity. Check this old post for how to check them. If the coil is the one piece molded Magnetron, make sure it is installed with the "this side out" facing you or the Magnetron pickup on the left side (facing the flywheel). Like Gary mentioned, there's really nothing else to go wrong with this simple solid-state ignition design.

http://www.simpletractors.com/club2/topic.asp?ARCHIVE=true&TOPIC_ID=8770

Tom (PK)

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CarlH

Tom,

Thanks for the link, I will spend some time digesting it. I understand the possibility of mismatched flywheel and Magnetron on an engine of unknown pedigree. I have assumed the old engine was running properly when the crank/rod got wiped. The Magnetron is installed correctly as I understand it. The high voltage lead exiting the engine side of the Magnetron. Given the routing of the spark plug wire, it would make little sense mounted the other way.

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PhanDad

Don't know if this will help, but here's Zippo's video on "Briggs Coil Magneto Magnetron installation tips":

Briggs Coil Magneto Magnetron installation tips

When I replaced one, I don't remember if the magnetron high voltage lead exited on the engine side or not, but I do remember it being on the right side so that you had to double it back to come out of the engine tin. In Zippo's video, the high voltage lead is on the right side (looking at the flywheel).

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CarlH

I got back to this today.

Gary, I have a solid ground at the Magnetron armature.

Tom, went through your referenced thread several times. It makes a lot of sense but I am not sure about how to determine if my flywheel is polarized correctly or not.

Bob, I also saw in the IPL that the desired flywheel has 2 red stripes. Where do I look for them? I dug out 3 16 HP flywheels plus the one I am working on. They all seem to have a dab or 2 of white paint on the ring gear/block side of the flywheel.

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powerking_one

Carl,

I'm not sure what other info you need regarding the magnet polarity question; as was stated in the post (old thread referenced), all you need is a simple compass to determine the polarity.

" Fact: the magnet polarity is indeed reversed from other Briggs models the Magnetron module IS supposed to work on. I checked this on 3 different engines:130232, 191702, 90XXX? and their polarities are all NORTH(compass points SOUTH). Hence my 243431 magnet is SOUTH (compass points NORTH)."

So when pointing the compass to the magnet and it points North, then the flywheel should be re-polarized for use with a Magnetron conversion.

Tom (PK)

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CarlH

Tom,

I haven't acquired a compass yet and have assumed the north - south orientation of the magnet section of the flywheel was along the circumference of the flywheel. Apparently, it is aligned with the radius.

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powerking_one

Speaking of Bob's (BLT) last comment about the 2 red paint stripes on a Magnetron flywheel, has anyone done and received a re-polarized back Briggs recently where they (B&S) added them? The last flywheels I had done is going on 12+ years and I honestly can't remember if the stripes were added; and no I'm not going to pull the engine and blower housings off to find out.

Tom (PK)

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