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Jayybird00

I think I killed my 725!

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Jayybird00

Let me preface this post with the fact that I am not mechanically inclined... at all. About a month ago I came across a 1963 Simplicity 725. I thought it’d be perfect to help keep down the weeds on my 5 acre property in Southern California. After the first few hours I accidentally kicked the s/g belt getting back on the tractor and it broke. Took me a bit of work to replace the belt. Rounded the bolts on the drive shaft. Sourced new bolts replaced the belt and I was off and running again. Shortly there after started having carb issues. Had to keep making adjustments on the screws. I seems to hit the sweet spot and off I went again. Then yesterday after about 2 hours of mowing the engine dies and white smoke billows from the head and exhaust. Won’t turn over and has/oil leaking from the bottom of the carb. The heads were smoking so after it cooled off I took the heads off and the fins were caked with this cotton like weed material and it was burnt too. So now I’m not sure what to do. I have a wonderful piece of lawn art. I’d love to get this up and running but I’m afraid it may be over my head. What to do?

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wwbragg

"You killed it, Gilbert."  (from Gilbert Grape).  But welcome aboard just the same.  Rebuilding that model 19 engine will cost you a finger and three toes.  A 13 HP Predator will fit nicely with minor mods.  See https://simpletractors.com/forums/topic/58197-flywheel-adaptor/?tab=comments#comment-466642

 

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Jayybird00

@wwbragg that looks great. Oh I know Gilbert Grape! Haha.  While I know there’s the love in keeping these machines original.  I really bought it to work not restore. There just isn’t anything out there built like these anymore and I love the looks and feel of it, although the steering has a some play in it too, but that’s another story. I wouldn’t mind the extra HP either. 

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MrSteele

Wish you were closer, I would rework it for the fun of it, and all you would be out would be necessary parts, likely only rings and gaskets. Obsolete just makes it more interesting. Did anything knock and sound like it broke before or during the white smoke incident?

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wwbragg
2 hours ago, MrSteele said:

Obsolete just makes it more interesting

I really admire you guys who can do that.  But even with the interest and desire, I lack the skills and money to pull off a full restore.  I call myself a "black box" mechanic.  But I do have a couple of 300421's I want to rebuild over the winter.  "Cover me.  I'm goin' in."

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Jayybird00

No knocking or anything like that just surged a bit then let go. I ordered a new head gasket thinking that’d be an obvious first issue. I might as well put it on and see what happens. It was easy enough to take the head off. Just not sure if I warped it or not. I had just changed the oil but I’m sure I added exactly what came out. I did use 5w30 synthetic. Could that have been my downfall? 

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MrSteele

The older engines ran 30 wt oil, with some changes due to weather, mostly use a lighter oil when cold as a wedge outside. If you still have the head off, use a long flat 10 or 12"  bastard file across the head making sure to keep the file flat, to clean the surface. Should have been a steel gasket, so nothing really to clean, just knock carbon gunk off the inside. With a file long enough, you will be able to see if the head is warped, by the shiny marks the file leaves. Most likely, it is not warped bad enough to not run a few more years. When filing, file in all directions, but always across at least two sealing surfaces. You can also put a piece of heavy grit, 24, up to 80 grit sandpaper on a flat surface, grit up, and rub the sealing surface of the head across the sandpaper to check for flat. Again, look for shiny /not shiny spots.

As for synthetic being your downfall? I personally, would not run synthetic in the older engines, but others swear by it. When I am close to putting a set of rings in, and being the mosquito fogger for the area, I have run 50 wt, up to pure STP or Lucas Oil Stabilizer. In a multi weight, you are at least running the oil that finally gets thick enough, one would think, to properly lube the engine

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MrSteele

Another thing. Now that you have the cover loose, use an air compressor and blow the remaining mouse houses out of your engine. The mouse houses are what caused your problem, not oil. There is likely more of that chewed up insulation, maybe a few acorns or hickory nutshells or pecans or whatever edible you have in the yard under the shroud of the engine. That blew into your cooling fins on the head, and all of a sudden you had no cooling, and something had to go. Clean it out good while the shroud is loosened for head removal. You will be amazed and filled with wonderment and awe, trying to figure out how they got something as large as you will find, through the tiny holes available. Give the engine a good blowing out. You can aim the tip under the flywheel, around the flywheel and the screens on the cover. Blow it out and away from the engine. The engine picks air up on the flywheel side, through the screen that is clogged in your pic above. The cover is a plenum that directs the cooling air up and out over the cooling fins on the head, and out through the grille.

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Jayybird00

@MrSteele Thanks for the optimism. It was 93 degrees outside while I was mowing. Everything was going great so I pushed it and just wanted to finish. I had been blowing it out after every use. But where that tightly packed plant fiber had wedged in between the fins I didn’t even consider. Now I know and hopefully I can clean her up and get it running again easily enough. But first I cave to figure a way to get it up to the garage! 

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MrSteele

Heck, it was 98 here when I cut the yard. BUT, I keep the mouse houses at bay, away from the engines I use. And, before using one that has been sitting for a while, the air compressor gets a workout. Everyone here and anyone using a machine that has sat over a winter, has had your problem with mouse houses, do not feel like you are the first to enjoy working on a machine because of them!!

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Jayybird00

Finally got it pushed up to the garage. Boy was that a work out. At least it didn’t die at the bottom of the hill! Took the top off again. Blew as much garbage out as I could. Took a wire brush to the area here are some photos. Gasket doesn’t look bad at all. 

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MrSteele

I would file or sand the head flat, blow the mouse houses to kingdom come, put it back together and give it a whirl. If you can, see that the valves are seating, by turning the crank til both open and close as they should. Be certain that the close completely. If so, put it back together, if not, PM me, and I will tell you how to go further, before putting the head back on. We might make a shade tree mechanic out of you! Clean the rust/dirt off of everything on the underside of the covers while you have it apart. The engine will thank you for the breath of fresh air across the cooling fins

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Jayybird00

So I called a good ole boy over to take a look at it before I put it back together. Local tractor mechanic. He was thrilled to see it. He told me “the pistons didn’t have much play for an old Briggs. “ And the valves looked good. He said everything looked pretty good and that I probably just over heated the engine. While he was here my new head gasket arrived too. So I cleaned it all up put the new gasket in and bolted it back together. Put a new spark plug in and it turns over no problem but no fire....

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ShaunE
38 minutes ago, Jayybird00 said:

Put a new spark plug in and it turns over no problem but no fire....

So based on the previous information & advise, your going to have to pull the engine out, remove the blower housing, remove the mouse nest remnants, blow out the cooling fins on the block & possibly remove the flywheel to examine the coil wiring if the rest of the tractor wiring is okay.  That model 19 has the old style coil under the flywheel & there are no magnets on the flywheel. The coil is NLA from Briggs but is available aftermarket.  eBay may even have some NOS.  There is only one wire on the key switch so if you wanted to test that, remove the wire & check for spark that way making sure the wire isn't grounded.

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Mine19821
wwbragg
2 hours ago, Jayybird00 said:

Is this what I’m looking for then?

@Mine19821 is correct assuming your tractor still has the original model 19 engine.  It certainly looks stock from the photos and I assumed it was the 19 from the very start.  But check the data plate to be sure.

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Mine19821
7 hours ago, Jayybird00 said:

 

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19d. Different coil yet. Not available either. I’ve got a 19d in my b1 that coil went bad on. Was converted to a battery ignition. My 23d is the same way. That d series Briggs was a odd coil. I’ve seen videos of how to put a Tecumseh coil on but not sure i want to pull the engine just for that! Coil off a car or old farm tractor works just fune for me. 

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simplewrench

eBay item number 272525360406 is the replacement I used on my 725 model 19. Just pull the coil off the “frame” and put on the new one. 

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Jayybird00

So after reading everyone’s reply’s it seems pretty apparent that the ignition coil is the likely culprit. What about going with a Nova II ignition module and just eliminating the points? Worth a shot? Seems easier than trying to find the appropriate coil. Has anyone gone this route with success? 

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PhanDad
1 hour ago, Jayybird00 said:

What about going with a Nova II ignition module and just eliminating the points?

Those modules eliminate the points, but not the magneto.  That still has to "work" to create spark.  

If you think the points aren't working properly, then the module might be a "fix"; but if the mag is being grounded somewhere (like under the tin), the module won't help and as stated above by @ShaunE, to find the problem, you'll have to pull the engine.  

 

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Jayybird00

I’m going to pull the engine tomorrow or Tuesday. I’ll be flying back east to upstate New York later this week for five days so the diagnosis will have to wait until I get back but I’ll keep everyone updated as I stumble and bumble through this 😉

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ShaunE

296834 is the Briggs & Stratton part # for the coil used for the 19D engine.  Based on my incorrect assumption in my earlier post thinking it was a Model 19.  There are a few ways to check all this depending on your comfort level.  First, use a spark tester & don't rely on the plug!!!  Then inspect all visible wiring for obvious breaks.  It helps to be in low light conditions for visualizing a grounding issue to see rogue sparks where they shouldn't be.  Remove the wire from the key switch & tape the end so it's not grounded.  If still no spark, then inspect, file, clean & reset the point gap to .020".  If still no spark, you can attempt to install a Nova II module & verify the point's are the culprit.  If still no spark, well then you are not going to be able to avoid pulling the engine any longer to access the coil & wiring under the blower housing.  

If it were me, I'd pull the engine right away, remove the plug & blower housing to clean & inspect the cooling fins, coil & wiring.  Then I'd inspect, file, clean & reset the point gap.  Then I'd use a drill & socket adapter to spin the engine to determine if I had spark or not before replacing the coil.

Edited by ShaunE
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