Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

eurolarva · Sep 11, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

You can test your busted flywheel theory. When motor is not working set the piston to TDC. At this point the ing modual should have just passed the magnet on the flywheel. Does this motor have an emergency kill switch. I am refering to the ones on push mowers that you have to hold or the motors stop. I am wondering if this may be shorting your ignition system and causing the motor to die. On your original post you mentioned that it would run only at low rpms. If this is the case then it cant be the kill switch or a busted flywheel key. Busted flywheel key will either back fire or rip your arm off when trying to pull the cord to start it.

fixin · Sep 11, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

I would try disconecting all the safety kill switches from the ign.It could be as simple as one of these wires grounding out.A lot of tractors have a kill if you fall off the seat and one on the oil.

12Footer · Sep 11, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

If it's a Vangaurd V-twin Briggs, check the fuel cutoff solenoid (I think they call the POS a "Anti-afterfire solenoid" or something off the wall like that), on the bottom of the carb. Look for a small can with one wire comming out of it.On the inside end, it has a needle that kills the fuel flow when ign is switched-off. The dang things are near useless. Symptoms of it failing were , it would 'run like a deere' until this gizmo failed, and it would stall,and not restart. You could get it to fire by spraying fuel into the carb throat,but it would quit picking-up fuel from the bowl---period. I got tired of replacing mine every season, so I removed it, plugged the hole with a short bolt,and brought a tiewrap up thru the cowling from the throttle linkage to kill the engine from low idle, when i finished mowing. It werked great for about 6 more years until it threw a rod. Just a guess, but easy to disable for testing.

dogsdad · Sep 11, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Eurolarva, that's a good idea. I'll check the TDC against the magnet position. Now, I think this ignition system consists only of a magnet on the flywheel and a coil/magneto. I have had the flywheel off, and all there is to be seen is a charging system stator. There is exactly one wire coming from the magneto (besides the two spark leads) and it goes to the ignition switch. When that wire is grounded, it kills the engine (the ignition switch applies ground to the wire when in the "off" position). If there is a pointset anywhere on the engine, it is very well hidden. Plus, I have a PDF document that shows exploded views of all the parts and a parts list. When I run a search for words like "points", "pointset", "breaker", "condenser", and so on, I get no results found. I would not say that I know that wire goes nowhere else (just floating) with the key in the run position, but I know the tractor will run (when it has a mind to) with that wire totally disconnected. So, if there's a pointset associated with it, it sure works funny. The seat safety switch prevents the starter from engaging and also kills the engine when you get off the seat with the mowing deck lowered. I do not believe there's a problem with any of that stuff because, as I said above, the engine won't fire even with that wire totally disconnected from the magneto. And when it was running, it would run with that wire disconnected so I am fairly certain the wire has only one function: to kill the engine. Also, there are no electrical solenoids or other devices associated with the carburetor. This engine is so stone-simple, but won't run. That's what's so baffling! I'm really focused in on the timing key that keeps the cam drive gear from spinning on the crank (supposedly). I think I'll go look at the TDC position right now and see what I can see. By the way, I went out today and bought a brand new John Deere LX280 this morning,

so I can cut my grass---what a SWEET machine! So, I don't have to fix the B & S, but it's a matter of pride at this point!

dogsdad · Sep 11, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Okay...now I think I will pull my hair out. Well, I would if I had any.

I just went out to the garage and I was going to remove a spark plug and check the static timing as eurolarva suggested. But a little voice in my head said "try the old original magneto again!" So I did. And the blasted thing fired right up. Because of my suspicions about the cam timing possibly being flaky, I then put the second and latest new coil back on. It would not fire! Then I put the old original coil on once again, and she fired up like a new machine. All I can come up with at this point is: 1. My theory about the cam timing was wrong, 2. The new coil/magneto is bad, 3. The old coil must be quitting on me due to heat or something, and 4. I need to get the highest quality coil/magneto I can find instead of whatever the lowest price on the internet will buy. I did verify once again while I was out there that the machine does run without any connection whatsoever between the magneto and anything else besides the plugs themselves. This has got to be the simplest spark ignition system ever devised! -dd-

Stumpknocker · Sep 12, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Damn.

jamesgreen · Sep 12, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

dd, I was a little disturbed when I read about this problem you have because I own about the same mower. Have you lost your mind turn the B&S into an anchor and enjoy the JD.

dogsdad · Sep 12, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

If I had a bigger boat, I just might indeed make an anchor outa that Briggs & Stratton.

James, I am 99.44% positive that a good, high-quality magneto will make that machine reliable again. I plan to fix it and get rid of it. The John Deere is in my shed to stay. I was apprehensive about telling my wife, who is known for her considerable frugality, that the Briggs could probably be fixed at a reasonable cost. But when I told her, she didn't seem to even think of sending the John Deere back to the dealership. I think she likes it even a little more than me!

I hope she slept okay last night and didn't fall off the seat. j/k -dd-

jimr · Sep 12, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

I had an old craftsman rider last year i bought for a song from my neighbor that would run for a while then start acting up. i ended up taking a side cover off so it would run cooler and it fixed the problem. dumped it this spring for 40 bucks more than i paid for it.

eurolarva · Sep 12, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Dogsdad send it to Minnesota. I have a few hairs left to pull out and I own a chyrsler outboard for the rest of the hairs. I could save a few for this beast. I dont think that motor has points. I think it is part of the ignition module that pulses the spark when it passes the magnet. I worked on a craftsman motor that worked that way. You are probably right on the coil. I know mercury went through a slew of problems revolving around defective coils. Ask anyone who owns a force motor. Good luck

ED21 · Sep 15, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Time to threaten it with a .44

dogsdad · Sep 17, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

My neighbor thinks we should put the old coil on it, put a cinder block on the seat, tie the steering wheel for a large loop pattern, and turn the thing loose out in the back pasture. Then shoot it with his Mini-30 (7.62mm X 39mm Russian military round). It's tempting. But I'm afraid it would refuse to die, and it would crash into the shed where my new John deere resides, where it would create great chaos and even try to destroy my green tractor. I think I'll just put a new magneto/coil on it and see if I can get a few hundred bucks out of it. Why tempt a possessed machine?? That's only asking for it!

-dd-

ED21 · Sep 20, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Sounds like a start for a Steven King novel.

starrider_68 · Oct 7, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

BTW DD did you ever get it to run right...or just end up shooting it?

Mark42 · Oct 8, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

Dogsdad, If it is still not running right, check that the spark plug wires are not grounding out, that the plug caps are in good condition (make sure the wire is not disconected internal in the plug cap). That motor should out last you. Mark

dogsdad · Oct 11, 2004

Re: Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

After two brand new but very cheap coils failed, the vendor sent me an original Briggs & Stratton magneto/coil. There is no doubt that this is the part causing the problem. By the way, there ARE NO POINTS or any other ignition components on this engine. Anyway, since I have a brand new John Deere

, my wife and I decided to give the old tractor to the lady across the street. Her husband has left, and I have seen her and her kids out there pushing a 20-inch mower all over their one acre plus lot trying to keep the grass from overtaking this part of the world. Man, I can only imagine trying to keep up with that. Hopefully the tractor won't give them any problems, but if it does, I've got my rifle loaded----err, I mean I have my toolbox handy. -dd-

Briggs & Stratton 16.5 HP Tractor: It's Possessed. Arrrggghhhhhh!

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