Briggs Coil Replacement, Restoration (Model 92502)

[TylerFrankel]

Ok ........... I'm back......... Scott and IL Engine gave you good advice........

Yes the magnets on your flywheel will work with the newer style Mag coils.......... I do it all the time.....

As for as the two wires on the old coil, one is a kill and the other goes to the points and condenser for spark....... If you put the mag coil on there those point wires can be clipped... Like Scott said, no need to pull the flywheel.........

Plus Tard Mon Ami ~!~!

Thanks everyone! I looked at it today more when I got home and found out it's a 1976 model! One of the other 4 I got had the modern electronic ignition, so I pulled it and after ensuring that it fit I began reassembling what I disassembled. I checked the valves to make sure they weren't loose in closed position to make sure I wouldn't have problems later, and they seemed tight. Then, I tried to clear out the oil and water from the sump as best I could being that I could only pull the thing off 1/2 an inch. Then, I re-bolted the base on with 3 screws. I then put the bolts back on the bottom of the head and head gasket (5 big screws). Then I replaced the muffler and carb/gas tank (1 screw). Next I put the coil and pneumatic governor back (2 small screws). Then the top went back on (3 medium screws), and the throttle (3 big screws that go into head too, 1 small 1 on tank. After I did all this, I realised the engine won't turn anymore, and I was left with 3 small screws same size as the one that screws onto the gas tank. I probably just missed something somewhere or put screws in the wrong spots, but everything went in flush so I'm baffled, but I'll tear it back down tomorrow. If anyone knows where they could go let me know please. I don't think I put the bottom on wrong because as far as I know the parts inside line up as the screws that hold it in do, and it turned after that before I completely reassembled it. Anyway.... I couldn't check for spark but tomorrow I'll be home before dark so I can work for longer and re-disassemble and assemble to let the engine spin again and figure out where the screws go,then check for spark again. After that, I plan to drill some holes into wood to make a stand and try to fire it with some gas and see what happens. Provided that fails, I'll rebuild the carb and check again. After that.... I'll be out of ideas.

I'll make sure to give it throttle when I'm trying to start of course, and I don't imagine the coil will not produce a spark because of a kill switch if nothing touches the tab right?

On an unrelated note, I have a briggs from 85 with a magnetron and manual start system 2 thats mounted on a deck and it works but I can't for the life of me figure out how everything works. It has a manual throttle control, it appears the kill switch connects to the deck, and theres wires running everywhere that none of the other engines I have possess. The motor adjusts the butterfly and speed under load, but there is no vane/pneumatic system. it also has a brake, whereas these engines don't. I wonder if the previous owner removed some of these parts...? and if they won't work because they don't have a kill system?

Again I really appreciate everyones ideas!

 

[Boudreaux In Eunice La.]

Tyler if you put only 3 bolts on the sump you are missing 3 bolts....... Your engine has 6 bolts...... I don't know why your engine is binding up ...... I wasn't there and I don't know how you put everything back together ......

Here's a short video I made a while back about a governor replacement..... This engine has 7 sump bolts...... Just 1 extra in the back of the engine..... Otherwise your engine is the same one as this one is just a lil smaller in size and you don't have the mechanical governor on yours.....

Enjoy ............

https://youtu.be/tqQQ618XeiE

 

[TylerFrankel]

Tyler if you put only 3 bolts on the sump you are missing 3 bolts....... Your engine has 6 bolts...... I don't know why your engine is binding up ...... I wasn't there and I don't know how you put everything back together ......

Here's a short video I made a while back about a governor replacement..... This engine has 7 sump bolts...... Just 1 extra in the back of the engine..... Otherwise your engine is the same one as this one is just a lil smaller in size and you don't have the mechanical governor on yours.....

Enjoy ............

https://youtu.be/tqQQ618XeiE

Ohhhhh I'm silly. Awesome video! I watched it and the governor you're talking about might explain the mysterious invisible governor on my other mower, but since the one I'm working on now is pneumatic then I shouldn't have disrupted anything by partially removing the base right? Only thing I can think of is the oil slinger so I'll try to peak in there and make sure it's on the green cam gear still, and then it should be fine I suppose when I put the base on. In the video the slinger has to be lined up with the governor, but I think mine doesn't (it just dangles there I guess) since my governor is pneumatic. Is this true? If not and I messed, I'll have to find a way to remove the darn blade mount to resettle everything. Anyway, tomorrow I'll re-disassemble the engine and figure out where the other 3 bolts go. I probably just put some long bolts where short bolts should go, maybe wedged one into the flywheel blades. I also bet an easy way to make sure the slinger hasn't gotten loose is to shake it around and see if I hear clanking lol...

 

[(Account Closed)]

I gather you adjusted the air gap for the coil about .010" (or with a business card) between the MAGNETS (on the flywheel) and the coil?

If not, that (if adjusted way too tight), would bind up...

Re the extra kill switch wires on the Magnetron. Some mowers had an additional kill switch wire often ran to the chute itself. If the chute was removed and not replaced with say a plastic mulcher "part/plug", being it NOW has an OPEN deck, that wire would kill the ignition-for safety reasons.

Some Briggs, depending on the style had the kill switch wire ONLY attached to the brake mechanism, older machines (with no brake) would be attached to the throttle assembly at the engine. As a side note, that little plastic "square" that the kill switch wire would go to, MANY engines have the square opening for it even thou it's NOT used. Briggs just left that square opening in later years. Depending on your engines throttle, you may be able to attach the kill wire to that "square" if installed and the actual throttle turns far enough to touch (kill it)..

Super old engines didn't have a wire at all. They had a tab attached to a head bolt that you pushed down and simply shorted the spark plug to ground killing the engine.

I just got this customers engine running (11 HP Briggs). If you look closely where the spark plug is, you'll see the tab (still painted red along with the spark plug cover-which has a small hole in it to allow grounding):

Just finished adjusting the RPM'S (3,600 as it's a generator). The black wire hanging loose is my tach.

 

[TylerFrankel]

I gather you adjusted the air gap for the coil about .010" (or with a business card) between the MAGNETS (on the flywheel) and the coil?

If not, that (if adjusted way too tight), would bind up...

Re the extra kill switch wires on the Magnetron. Some mowers had an additional kill switch wire often ran to the chute itself. If the chute was removed and not replaced with say a plastic mulcher "part/plug", being it NOW has an OPEN deck, that wire would kill the ignition-for safety reasons.

Some Briggs, depending on the style had the kill switch wire ONLY attached to the brake mechanism, older machines (with no brake) would be attached to the throttle assembly at the engine. As a side note, that little plastic "square" that the kill switch wire would go to, MANY engines have the square opening for it even thou it's NOT used. Briggs just left that square opening in later years. Depending on your engines throttle, you may be able to attach the kill wire to that "square" if installed and the actual throttle turns far enough to touch (kill it)..

Super old engines didn't have a wire at all. They had a tab attached to a head bolt that you pushed down and simply shorted the spark plug to ground killing the engine.

I just got this customers engine running (11 HP Briggs). If you look closely where the spark plug is, you'll see the tab (still painted red along with the spark plug cover-which has a small hole in it to allow grounding):

Just finished adjusting the RPM'S (3,600 as it's a generator). The black wire hanging loose is my tach.

Awesome. So that kinda helps me understand my functioning mower, I guess there are 2 kill switches; 1 from the handle that goes to a brake and 1 that engages when the throttle is closed all the way (it can be stopped both ways). This one I'm working on looked like it had the kill wire bare near the throttle, so I imagine this is how it would be grounded/killed... I'll take note of that when I want to set it up. For now I'll ground it manually. Interesting. Thanks.

The coil is spaced properly, I realized I put the screws meant to be in the sump in the cover, which are too long and probably preventing the flywheel when turning. Will update when I get home.
Thanks

 

[TylerFrankel]

Awesome. So that kinda helps me understand my functioning mower, I guess there are 2 kill switches; 1 from the handle that goes to a brake and 1 that engages when the throttle is closed all the way (it can be stopped both ways). This one I'm working on looked like it had the kill wire bare near the throttle, so I imagine this is how it would be grounded/killed... I'll take note of that when I want to set it up. For now I'll ground it manually. Interesting. Thanks.

The coil is spaced properly, I realized I put the screws meant to be in the sump in the cover, which are too long and probably preventing the flywheel when turning. Will update when I get home.
Thanks

Update:

Big progress. I fixed the issue with the screws and actually put them back right, then tested for spark. It sparks well enough, not quite as bright as the mower but I can see it go. Then I put it on some wood and pulled it over a few times after adding 15oz oil. (not quite enough but enough to test if it starts). It doesn't have a blade, and I noticed when I was pulling it over that it seemed to have good compression. A couple times it yanked back hard, which I imaging is kickback. I'm pretty sure this means the engine is firing and the carb is providing fuel properly. Then, I went to pull it once and got a good kickback and a puff of smoke out the carb. Probably backfiring because of kickback, but anyway this means we have fire! and I shocked my toe on the spark plug to check. :tongue: Now I suppose the order at hand is putting a blade on and finding something to mount it to so I don't lose my hand trying to start it. I think I'll do this with a blade from another mower and some wood and bolts to mount. I'll wear safety glasses too of course. If it starts well, I'll finish the first engine off by dumping the oil again and checking the oil sprayer to make sure its in tact, then replace the gasket and oil. And, maybe find a way to take off the stupid blade mount, although I suppose I could use it to attach other things.

 

[Boudreaux In Eunice La.]

You need to get you a good 3 jawed puller...... The kind that can be converted to a 2 jaw puller........ That will get your blade boss off easy.....

It has to come off to take the sump off all the way.......

Tired of typing got to go......

 

[dana a]

IT WOULD BE BEST TO MOUNT THE ENGINE TO ANOTHER MOWER DECK. Starting it with a blade on it mounted to wood could be very dangerous. For testing purposes, an easy way to kill the engine is to close the choke. Instead of rigging up a throttle cable use your finger to work the throttle.

 

[(Account Closed)]

IT WOULD BE BEST TO MOUNT THE ENGINE TO ANOTHER MOWER DECK. Starting it with a blade on it mounted to wood could be very dangerous. For testing purposes, an easy way to kill the engine is to close the choke. Instead of rigging up a throttle cable use your finger to work the throttle.

Plus 100 ^^^

 

[tom3]

Couple quick points.

The blade acts as a second flywheel, sure would help eliminate the kickback you're seeing. And converting points to electronic ignition with the solid state coil does increase the spark advance a couple degrees, makes for a bit more power but could also be causing the kickback without the blade on the motor. Those old motors are probably the usual plain aluminum bores, need to use the correct oil for any life from that. Today's oils have eliminated much of the barrier lubrication needed for this design.
Working on these simple motors is interesting and even fun sometimes.