Briggs 3HP 80292 magnetron conversion?

[cwilliamsws6]

I have a rototiller I got for free, and it has a Briggs 80292 engine with a points and condenser ignition.

I do not have spark and I would rather not pull off the flywheel and mess with the points and condenser, so what do I need to do to convert it to use a newer magnetron ignition?

From what I have read in other places it should be as simple as swapping in a 398593 or 591420 coil, right?

My flywheel has 2 magnets and they seem pretty strong. The flywheel was covered in rust and I got it as clean as I could with some sandpaper.

 

[Fordiesel69]

im terrible with parts numbers but yes it is that simple.

 

[fozzdesy2001]

I have a rototiller I got for free, and it has a Briggs 80292 engine with a points and condenser ignition.

I do not have spark and I would rather not pull off the flywheel and mess with the points and condenser, so what do I need to do to convert it to use a newer magnetron ignition?

From what I have read in other places it should be as simple as swapping in a 398593 or 591420 coil, right?

My flywheel has 2 magnets and they seem pretty strong. The flywheel was covered in rust and I got it as clean as I could with some sandpaper.

you need to pull the flywheel so you can clean the points or replace them. I had one model WI from the late '40s and that's all it needed. And a model 6B, sort of like your 80292, that really did need a new coil. Pulling the flywheel is the only way you are going to get to the points and get it going if it has no spark. You can use a coil off any 3-5 hp Biggs flat head and if it has Magnatron ignition you don't need to worry about points or pulling the flywheel. Do the coil swap it's the best way

 

[Gyro Gearloose]

When I was struggling with a mower that had no spark even with a new magneto I ran across some information on other forums that said there were some years of engines and pointless magnetos where the north and south poles of the flywheel magnets were reversed to operate the trigger on the magnetos and the old standard north south orientation won't trigger a spark. I've said more than I actually know on that subject so I'll stop right there. What I have experienced personally is a horrible failure rate on non B&S aftermarket magnetos. 2 DOA and the third only lasted a year. FWIW I think the points systems produce a stronger spark at cranking rpm.

 

[cwilliamsws6]

When I was struggling with a mower that had no spark even with a new magneto I ran across some information on other forums that said there were some years of engines and pointless magnetos where the north and south poles of the flywheel magnets were reversed to operate the trigger on the magnetos and the old standard north south orientation won't trigger a spark. I've said more than I actually know on that subject so I'll stop right there. What I have experienced personally is a horrible failure rate on non B&S aftermarket magnetos. 2 DOA and the third only lasted a year. FWIW I think the points systems produce a stronger spark at cranking rpm.

I think I read somewhere that I'd have to get the flywheel repolarized if I went with a pointless magneto, but supposedly I could just mount the coil backwards and it would also work fine. Could you confirm or deny that much?

 

[FowVay]

I'd just buy a set of points and a condenser and change them. They'll last 50 years and they're only $15. Every man needs to know how to replace and adjust points and condensers.

 

[wag123]

From what I have read in other places it should be as simple as swapping in a 398593 or 591420 coil, right?

Affirmative. You want to cut the wire that goes to the points.
Only one question remains. Did you lose spark because... the points are bad and need to be replaced, or was the flywheel key sheared? Unless you pull the flywheel you won't know if the flywheel key is good and it still may not run (or it won't run right) if the key is sheared.

 

[jeepman3071]

I'd just buy a set of points and a condenser and change them. They'll last 50 years and they're only $15. Every man needs to know how to replace and adjust points and condensers.

Not quite. The quality of newer points/condensers means you will be fiddling with them often.

 

[Gyro Gearloose]

I'm afraid I'm out of information on the magnet thing. I only mentioned it because I ran across it on a forum as one of the odd reasons why a new replacement coil may not work, which was the issue I was dealing with at the time. Hopefully you can slap a new coil on and it will start first pull. But if it doesn't.......

Coils are not reversible, at least I've never seen one that was. They are designed mechanically so that there isn't enough room for the spark plug wire attachment if attempted to be mounted upside down. And functionally it would not work because the trigger is at the edge of the coil, not the center, therefore flipping the coil would put the trigger out of time with respect to both the crankshaft and the magnets as they pass the inductive part of the coil.

 

[cwilliamsws6]

Affirmative. You want to cut the wire that goes to the points.
Only one question remains. Did you lose spark because... the points are bad and need to be replaced, or was the flywheel key sheared? Unless you pull the flywheel you won't know if the flywheel key is good and it still may not run (or it won't run right) if the key is sheared.

I think it's pretty safe to say the points are bad. This rototiller, according to the guy I got it from, has sat outside uncovered for 20+ years so I imagine they're rusted away or corroded beyond being savable. I'll still pull the flywheel and inspect though.

 

[cwilliamsws6]

Okay so I spent a good while messing with it today and here's what I found.

I was mistaken earlier, my flywheel only has one magnet, not two. The flywheel key is also good still.

The points and condenser looked brand new but I still cleaned them off and tried adjusting them a couple of times but still couldn't get spark. With how easily everything came apart it's obvious that I'm not the first one who's tried messing with it. Starting to think it's a bad coil now.

Since the flywheel has one magnet, not two, technically I could get away with swapping in a pointless coil and using the magnet on the flywheel for timing, right?

 

[wag123]

Okay so I spent a good while messing with it today and here's what I found.

I was mistaken earlier, my flywheel only has one magnet, not two. The flywheel key is also good still.

The points and condenser looked brand new but I still cleaned them off and tried adjusting them a couple of times but still couldn't get spark. With how easily everything came apart it's obvious that I'm not the first one who's tried messing with it. Starting to think it's a bad coil now.

Since the flywheel has one magnet, not two, technically I could get away with swapping in a pointless coil and using the magnet on the flywheel for timing, right?

You don't have to time anything with a B&S magneto, either a points type or a magnetron type. The timing is accomplished by the flywheel key. The number of magnets the flywheel has is not relevant.

 

[cwilliamsws6]

You don't have to time anything with a B&S magneto, either a points type or a magnetron type. The timing is accomplished by the flywheel key. The number of magnets the flywheel has is not relevant.

I just wanted to make sure because I read somewhere that if the flywheel has 2 magnets you need a 3 leg coil and the pointless coils are 2 legs. Which since I only have one magnet I guess that's a non-issue now anyway.

 

[wag123]

I just wanted to make sure because I read somewhere that if the flywheel has 2 magnets you need a 3 leg coil and the pointless coils are 2 legs. Which since I only have one magnet I guess that's a non-issue now anyway.

Just buy the magnetron magneto that goes to your model and type number. Don't worry about how many legs it has or how many magnets your flywheel has. The correct part number is 591420.

 

[cwilliamsws6]

Just buy the magnetron magneto that goes to your model and type number. Don't worry about how many legs it has or how many magnets your flywheel has. The correct part number is 591420.

Okay I will order one from eBay when I get paid tomorrow, then all I have to do otherwise is just snip the wire going from the points to the coil, correct?

I'm just making sure I do this right the first time because I got this for free so I don't want to sink a ton of money into it and have to constantly revisit things.

 

[mk378]

Yes if you have the kill switch that directly shorts out the spark plug, don't connect anything to the small terminal on the electronic coil. If there is a kill switch wired to the throttle lever, connect it to the small terminal on the coil. The points and condenser and its wire are to be abandoned.

 

[cwilliamsws6]

Yes if you have the kill switch that shorts out the spark plug, don't connect anything to the small terminal on the electronic coil. If there is a kill switch wired to the throttle lever, connect it to the small terminal on the coil. The points and condenser and its wire are to be abandoned.

My engine has the tab on the top to short out the spark plug so wiring for a kill switch won't be needed.

While I still have it all taken apart should I go ahead and remove the points and condenser entirely or is there no harm in abandoning it in place?

 

[wag123]

My engine has the tab on the top to short out the spark plug so wiring for a kill switch won't be needed.

While I still have it all taken apart should I go ahead and remove the points and condenser entirely or is there no harm in abandoning it in place?

Leave it.

 

[Gyro Gearloose]

You will actually want the points components left intact to keep the little "lifter" that operates the points inside it's hole. If that lifter comes out crankcase pressure will blow oil/suck dirt through the hole. My memory is that it is located on the crankcase side of the oil seal.

 

[cwilliamsws6]

You will actually want the points components left intact to keep the little "lifter" that operates the points inside it's hole. If that lifter comes out crankcase pressure will blow oil/suck dirt through the hole. My memory is that it is located on the crankcase side of the oil seal.

Good to know, never thought of that. Will definitely leave it all in place. Thanks