I'd try removing the spark plugs (ground the wires) and try cranking the engine.
IF a cylinder is filled with gasoline, it will "push" it out.
You don't want a spark!!!!!

You mean start it by turning the flywheel by hand right? I get a tiny small "puff" for the 1st few times and then after that nothing.

I think I have a faulty ground somewhere. If I leave the key turned to the start position I no longer get a "click" but the connection by the starter wire from the solenoid starts to smoke after 5 -10 seconds.

If it is a bad ground, what do I do? How do I fix that?

I didn't necessarily mean to crank by hand.
IF the cylinders are full of fuel, the engine isn't going to crank- PERIOD!

IF it spins "normally" (with the key) with the plugs out, that gives a better idea where we're at.

IF the cylinders were full of fuel, the carb will need to be fixed to cure the leaking needle/seat assembly.

BTW, that engine only has a 3 Amp CHARGE SYSTEM. IF the battery is low, it'll take HOURS of running to fully charge it.

The engine doesn't crank at all with the key. That is why I assumed you meant to "spin" the flywheel by hand. With the spark plugs removed, the flywheel spins about 1 revolution when I spin it by hand and then it stops.

Right now, when I turn the key to start the engine, I don't get any response at all from the tractor. No click, No puffing, nothing.

The battery is brand new and puts out 12.4 volts. The terminal at the solenoid from the Pos bat. also has 12.4 volts. The terminal at the solenoid (to the starter) has only 6.4 volts when the key is turned. The starter also only has 6.4 volts when the key is turned. The starter doesn't move at all when the key is turned.

"With the spark plugs removed, the flywheel spins about 1 revolution when I spin it by hand and then it stops."

?? You can't turn it on by hand at all? That ain't good.

"Right now, when I turn the key to start the engine, I don't get any response at all from the tractor. No click,"

The engine HAS to turn freely by hand with the plugs out or no use worrying about anything else. There will be some periodic resistance as the valve work but still should be able to turn it thru.

I doubt if you will hear any more from Bill right away, you see, he has to ride his bicycle to the Library to use their Internet and only is on a little bit about week apart.

Walt Conner

Thanks Walt and Bill for the responses.

I had a feeling the flywheel should spin freely but wasn't sure. This is my first time fixing this tractor. Even when i do spin it by hand it REALLY TOUGH and I have a couple hundred lbs. of force behind it ;>).

I should also let you know that I did have a fuel line clog last week that I cleared. There was a clump of grass in the line prior to the filter. Given that the line was a little dry rotted, I replaced the entire Fuel line and the fuel filter from the tank all the way to the Carb. The tractor did start and I ran it for 1 grass cutting, about 90 minutes.

What I didn't notice orginially was there was gas "dripping" out of the from of the carb. The gold colored plate where the fuel line attaches. I think it is called a diaphram pump. Is this normal?

It sounds like you both leading me down a path of too much gas in the pistons, how do I clear it?

Also is the voltage issue I have (or at least think I have) related or entirely separate?

***"It sounds like you both leading me down a path of too much gas in the pistons, how do I clear it?"***
Whoa! We need to establish some facts. While "too much gas in the pistons" is definitely A PROBLEM......it IS NOT what you need to focus on. Liquid gasoline in the cylinders is a consequence of, and evidence of, a BIGGER problem or defect. And, if what you are describing (in how hard it is to turn the engine by hand with the spark plugs removed) is true, you may already have severe engine damage.
Have you checked the engine lube oil level since this problem arose? Is the oil level "over full"? If over full, is the oil thin (compared to fresh oil)? If over full, does the oil "smell like gasoline"?
***"Even when i do SPIN IT BY HAND it REALLY TOUGH and I have a couple hundred lbs. of force behind it ;>)."***
Does this mean you are spinning it with the manual recoil rope?
***"I get a tiny small "puff" for the 1st few times and then after that nothing."***
Puff of what? and from where?
What Bill wanted you to do was: REMOVE the spark plugs from the engine and try spinning the engine with the plugs removed. His instructions to "ground the spark plug wires" was to prevent a stray spark from igniting any fuel that might be expelled from the spark plug holes. You can "ground" the plug wires by putting the spark plugs into their plug wires (plugs out of engine) and wrapping each plug completely up with a paper towel soaked with water. Lay the wrapped plugs on a metal part of the engine or chassis, as far away from the open spark plug hole as you can get them. The wet towel trick will effectively "kill" any spark. If there was gasoline in the cylinders, the gasoline would be expelled or ejected out the spark plug holes when you spin the engine. And, if you OBSERVED gasoline being expelled out the spark plug holes, this would proved that your carburetor was leaking fuel and "drowning" the engine (filling the cylinders). If this was occurring, some of the gasoline would have seeped into the engine crankcase where it would dilute the engine lube oil AND, cause the apparent oil level to rise (read higher on the dipstick). BUT, there is a significant "problem" with the hypothetical scenario I just described (would it apply to your engine and present situation??). YOUR engine is shown to have a FUEL PUMP! Engines that utilize a FUEL PUMP are generally "immune to" the problems of leaking fuel into the engine when in storage. The problem of a carburetor "drowning" the engine is generally only found with machines that have a "gravity fed" carburetor.
A "gravity fed" fuel system will have the fuel tank situated above the carburetor (meaning that the fuel tank is mounted higher in elevation than the carburetor). If your tractor has the fuel tank situated at a level that is below the carb level, it is doubtful that you have a "drowning" issue.
You stated "The battery puts out 12.4 v and the soliniod has 12.4 when the key is turned but the starter only get 6.4 v."
How are you determining (where do you connect your meter) that the "starter only get 6.4 v" ?
Go back and do the tests that Bill asked for. If you have been pulling the rope, with the spark plugs installed.....I'll bet you got tired. It should turn fairly easy with the plugs removed.
Try to respond to each of the details in this post and we'll try to go from that point. We may have been singing from different song books so far.

I'll leave this to Mownie since I am going to be off line anyway.

Please don't tell us that you didn't check the oil level BEFORE starting the engine last time.

Walt Conner

This is only a possibility.. On autos when you get that "clicking" it can be caused by something as simple as dirty battery terminals.

Thanks again guys. I'll do my best to test each scenario you gave and respond as well as I can you each one. I think I'm at the point of having to bite the bullet and take it to a shop once I save up some cash. As you can probably tell, I'm far from a small motor mechanic. I'm much closer to a bumbling tinkerer that likes to take things apart so please excuse my ignorance.

*****Have you checked the engine lube oil level since this problem arose? Is the oil level "over full"? If over full, is the oil thin (compared to fresh oil)? If over full, does the oil "smell like gasoline"?
*****
Yes, I have checked the oil level and it was elevated. It was approx. 1.5 inches over the high mark on the dip stick. I didn't take notice to the viscosity of it though. I did drain it out and refill with new oil since the problem started. In hindsight, the oil drained "faster than normal" so it may have been thinned out but I didn't notice any gas smell.

*****
***"Even when i do SPIN IT BY HAND it REALLY TOUGH and I have a couple hundred lbs. of force behind it ;>)."***
Does this mean you are spinning it with the manual recoil rope? *****
I don't have a recoil rope. I was just "spinning" the flywheel by putting 2 hands on top of it and turning it as fast and as hard as I could. Stupid question, but could I attach a manual recoil rope? If so, is there a kit to do it?

*****
***"I get a tiny small "puff" for the 1st few times and then after that nothing."***
Puff of what? and from where? *****
The "puff" is a sound I would get. I didn't notice any smoke or any visual sign.

***** How are you determining (where do you connect your meter) that the "starter only get 6.4 v" ? *****
I connect the multimeter Neg. to the battery Neg. terminal. The multimeter Pos. was connected to the Terminal nut of the starter. It reads as 0.0 until the key is turned. When I turn the key, the reading jumps to 6.4 or close. I would assume it should read around 12.0. Also if I leave the key in the start position, the terminal at the starter ACTUALLY SMOKES and starts to smell like it is burning.

I did do the test Bill described or at least my close interpretation of it...
Here is what I did;
1. I removed both spark plugs from the block,
2. I hooked both spark plugs to the plug wires,
3. I covered both spark plugs with fire retardant cloth, (I assume this works like the wet paper towel)
4. I attempted to key start the engine but nothing happened,
5. I attempted to turn the flywheel with 2 hands since I didn't know I could use a recoil rope.
6. The flywheel turns about 1 revolution and stops abruptly.

Also I see what you mean about the hypothetical scenario but did you see my previous post? Prior to my engine being "dead" or should I say when it was running as of 6/7 I did visually see gas dripping out of the diaphram pump cover when the engine was key started and running. It was dripping about a drop of gas per second. Once I noticed the gas drip, I stopped the engine within a 2-3 minutes and it has never started again.

Again guys, I appreciate all the help. So I'm not sure if this will help but below is a rough timeline of my issues.

6/7 noon Cut grass about 1 acre but stopped mower prior to finishing.
6/7 3 PM went to restart tractor but it spin but never start. Tried about 6-8 times to no avail. over the next few hours.
6/7 7 PM this is when I noticed there was not a single drop of fuel in the fuel filter even though tank was 1/2 full.
I filled the gas tank and still no luck.
I also checked the oil and did notice the oil was higher on the dipstick then normal.
6/8 9 AM I disconnected fuel filter and still wasn't getting any fuel from the tank through the hose.
6/8 10 AM I found a "clump" of grass in the line and decided to replace the fuel line and fuel filter since the line was slightly dry rotted and the filter wasn't replaced since 2008.
6/8 noon. Tractor started with the key turn BUT This is when I noticed the "Dripping" of fuel from the diaphram pump cover.
6/8 1 PM --- this is where I probably overestimated my repair ability ---
I disassembled the Diaphram pump to see why gas would freely drip out of it.
6/8 3 PM I reassembled the diaphram pump BUT the installed the cover upside down so the vent holes were on top rather than the bottom.
6/8 4 PM The tractor started BUT **I'M NOT KIDDING HERE** GAS shot out of the open hole in the diaphram cover approx. 3 feet straight out in a continuous stream. I turned the engine off within 5 seconds.
6/8 5 PM Realized the cover was upside down and reinstalled correctly and restarted tractor. Gas still aggressively dripped from the cover. About 1 drip per second.
6/9 9 AM Attempted to start tractor but battery was dead. Attempted to jump start the tractor but it wouldn't start at all.
6/9 11 AM Installed New battery since old battery was 4 yrs old.
6/10 noon. Still no luck starting. I only got a "click" when turning the key.
6/10 4 PM. Replaced the solenoid.
6/10 5 PM Still no luck starting. I only got a "click" when turning the key.
6/11 9 AM Same as prior post.
6/11 10 AM Started to test electric voltage. Noticed started wasn't getting same voltage as battery output. Starter was only getting 6.4 volts at starter terminal connection.
6/12 started thread here.
6/13 9 AM attempted to start tractor. Now I no longer get the "click" when turning the key.
6/14 11 PM. Noticed I'm in over my head, have grass up to my knees, have no idea about small motor repair, and don't have enough money to pay someone to fix it yet... Ugh....

If your starter is smoking I'd say you have a short in the starter.
Smoke is usually a good indicator of a short as is you have a voltage drop of 6 volts.

***"6. The flywheel turns about 1 revolution and stops abruptly."***
That sentence alone (taking all the other details of the "timeline" into account) is enough to indicate the engine may have incurred some major damage. I will attempt to cover some of the points you stated (BTW, that's a comprehensive "timeline of events" compilation). It may seem that I'm "rambling" as I use some of your "quotes" to preface my remarks (won't be the first time I've been accused of rambling on).
.....................................
***"oil level and it was elevated. It was approx. 1.5 inches over the high mark" ; "the oil drained "faster than normal"***
Those are fairly strong indications of oil dilution from gasoline leaking into the crankcase, especially the 1.5" over full.
...........................
***"I was just "spinning" the flywheel by putting 2 hands on top of it and turning it as fast and as hard as I could"***
That's OK. That method is what (I think) most of us "pictured" anyhow. Very few "big engines" come equipped with "recoil rope" auxilliaries anymore. You would have to be Superman to start one with a rope, so the OEMs don't bother with them.
..............................
***"I get a tiny small "puff" for the 1st few times and then after that nothing."***
OK. The "pufff" came out the spark plug hole, I presume. That part is OK. The part "for the 1st few times and then after that nothing" is sort of vague. When you say "first few times", do you mean "first few complete revolutions of the engine"? (because you also stated "6. The flywheel turns about 1 revolution and stops abruptly.") OR do you mean that you turn the engine in one direction until it stops abruptly and then turn it in the other direction until it stops abruptly and then turn it back the other direction until it stops abruptly.....................????
..................................................
***"I connect the multimeter Neg. to the battery Neg. terminal. The multimeter Pos. was connected to the Terminal nut of the starter. When I turn the key, the reading jumps to 6.4 or close. I would assume it should read around 12.0 . if I leave the key in the start position, the terminal at the starter ACTUALLY SMOKES and starts to smell like it is burning."***
OK, the way you made your connections is correct. That you saw a reading of 6.4V may only indicate that the battery has become discharged due to "a lot of cranking", but no recharging during the period since the last time it ran. BUT, because of the smoke and burning smell, the starter is possibly "fried". Low battery voltage will kill a starter in just a couple of minutes. The heat builds at an exponential rate (as the heat builds, resistance increases which cause even more heat and resistance which causes more heat ad infinitum). So, your starter may have said "so long cruel world". But you don't need to focus on the starter right now.
...................................................
***"I covered both spark plugs with fire retardant cloth, (I assume this works like the wet paper towel)"***
Anything you can do to "suppress a spark" will work, HOWEVER, simply "covering the plugs with something" or "tying the plug wires up" away from the engine or other "grounded" component of the engine or chassis IS NOT, (say it again), IS NOT equivalent to GROUNDING THE PLUG WIRES!! In fact, trying to "insulate" the plugs from a grounded surface can actually cause the spark to occur somewhere else in the plug wire (if the OEM rubber insulation is cracked or pinched somewhere on its way back toward the magneto coil). The reason I recommend the paper towel, wet with water, is because the water will conduct the electrical energy (voltage potential) away from the plug and dissipate the energy into the grounded surface over a broad area and very effectively "suppress a spark"! Just about everybody has paper towels and water handy, so it makes for a quick and effective way to kill the spark. An "old plug" with the ground electrode "hammered" against the center electrode works even better with the watered towel. You can also kill the spark a number of other ways (jumper wire into the plug boot and clip other end of jumper to grounded component, jumper wire to the "kill wire" of ignition coil circuit, and some other etc.). But, not everybody has "jumper wires" lying around. Some ignition systems don't feature a "kill wire" like Briggs does. So I suggest the "watered paper towel" method because it is effective and easily reproduced by anyone, no matter how "sparse" their toolbox, or experience may be. And because this trick works on ALL ignition systems, no matter how they are configured. UNDERSTAND that we are not trying to suppress the "flow of energy" from leaving the ignition coil. We are trying to "route" the energy into a grounded surface to prevent the energy from creating a spark. There's a huge difference between the two scenarios.
Anyhow, you didn't catch fire........and that's the main thing in this pursuit.
................................................
I'll say some words about the gasoline leakage problem now.
I stated earlier in another posted reply that "fuel pump fed carbs are generally immune to causing "drowning" of the engine while in storage. That is true, but there are some machines out there that should be considered "hybrid" in that the specific elevation of the fuel tank will have the fuel level (in tank) above the carburetor when tank is full, but the fuel level falls below the carb when fuel is consumed. These "hybrid" fuel systems require a pump to make use of the fuel when the level in tank falls to a point below the carb. In these systems, the problems of "fuel drowning" due to carb overflow (leaking needle valve) are still "possible" (when the tank is full). But, a defective fuel pump can leak or "feed" gasoline into the crankcase (and the oil) through the "pulse vacuum" hose that operates the pump. I am beginning to think (due to your very good description of the leaking gas) that your fuel pump may have been the source of the gasoline into the crankcase.
......................................................
At this point, you need to go back to the engine and see if it will turn complete revolutions in either or both directions (spark plugs out of engine). If it will not turn any complete revolutions, you need to start saving your money, your engine might be "trashed". We might be able to help you "tear down" the engine to "perform autopsy" (if you report back that the engine definitely DOES NOT turn complete revolutions) but as you have stated, "I'm far from a small motor mechanic. I'm much closer to a bumbling tinkerer that likes to take things apart", but that would be up to you. Report back on the "complete revolutions" thing and we'll go from there.

I just did the test with the paper towels and the results are below.
the flywheel makes about 1.25 revolutions in either direction, clockwise or counterclockwise. I'm tracking the Briggs label going around.
The "puff" is coming from the spark plug openings and there is gods compression in both plug openings.
The "bad" news is the oil does smell like gas. And the oil is about a 1/8 inch over when I changed it last week.

If I could save a few bucks, I'm ok to tear apart the motor. I think I'm 1/2 there already. I'm also fine with the embarassing moment of taken a torndown motor to a repair shop

Any ideas what to try next?

Try a trip to the place where they sell new lawn mowers and tractors, and buy a new one, and also buy the maintenance plan! This will solve your problems, and also keep the grass from growing head-high!
By: Rustyj

Makes me wonder if the starter is binding up the flywheel. I would pull the starter and bench test it. While it is off see if the engine will turn over easier. "A shot in the dark."

Also I just noticed there is gas dripping out of the pump cover every time i spin the flywheel. It seems to drip at a greater pace when I spin the flywheel counterclockwise.

Also when I turn the flywheel slow counterclockwise it makes a sound like "phphphphssss" almost like a soda bottle when it is opened slowly. Sounds like something is draining.

Go ahead and drain the gas out of the fuel tank, you might as well pour it into your car. You will not need gas in the tractor tank for a while. The gas dripping is no longer "bad news". It was bad news before this point. It is just expected news now. The 1.25 turn in either direction is what I call bad news. If you feel OK to remove the cylinder heads, you can go on and do that. You may end up taking the engine out of the tractor later, but for now, you'll just be removing parts and doing more inspection. I suggest that now is a good time to begin taking a lot of digital photos of your teardown in order to "blaze your trail for the return trip" These photos are not for my benefit, they are to help you during reassembly, so don't be shy about shooting a bunch. Draw sketches, make diagrams, make tags, mark with crayons or markers........whatever you need to do in order to retrace your steps later.
If you have not yet gone to the Briggs website for the IPL of your engine, click the link below. You should "save a copy" of the PDF manual into your computer so you can view it offline AND make prints easily if you need to. I'll make another post with details of what you will do after the heads are off.

Here is a link that might be useful: IPL link

***"Also when I turn the flywheel slow counterclockwise it makes a sound like "phphphphssss" almost like a soda bottle when it is opened slowly. Sounds like something is draining."**
Is this happening when the spark plugs are removed from the engine?? If yes....is the "phphphphssss" coming from the fuel pump???
.............................................
To define "UP" & "DOWN" as relating to piston movement, learn this:
When a piston is moving TOWARD the cylinder head, the direction of movement is referred to as UPWARD, or UP. When the piston is moving AWAY FROM the cylinder head, it is referred to as DOWNWARD or DOWN. This applies to all reciprocating engines regardless of the engine configuration. Just remember that the terms are for one specific cylinder at a time, no matter the total number of cylinders the engine has, or which direction they may be pointing (clock position).
......................................................

With both cylinder heads removed, turn the flywheel while watching either of the pistons. As you turn the flywheel, is this piston moving in its cylinder (meaning: traveling upward or downward). Turn the flywheel until it reaches the point of "abrupt stop". Now, watch the same piston while you turn the flywheel in the opposite direction. Does this piston move in the opposite direction JUST AS SOON AS YOU TURN THE OPPOSITE WAY? or does it seem that the flywheel rotates a few degrees before the piston begins to move in the cylinder? Continue turning the flywheel until it abruptly stops again. Now, watch the same piston as you turn the flywheel again in the direction you first turned it. Does the piston begin to move in the opposite direction immediately? or does the flywheel seem to rotate a few degrees before the piston begins to move? Go to the second cylinder and repeat the steps above for that cylinder. What we are doing in this "test" is determining whether the piston, connecting rod, and crankshaft are still intact (I only mean they are still connected together as an assembly). Due to the "1.25 turn" you cite, I expect you to find that one of the pistons will have a "dead zone" of movement in its travel. This is when the flywheel rotates a few degrees without the piston moving. The "dead zone" of movement will be at the max UP and max DOWN positions. If you find this to be true, the connecting rod is very likely "burned up" from loss of lubrication due to the oil being thinned out by gasoline contamination. If you find the "dead zone" of piston travel, you will want to compare the piston travel distance of one cylinder to the other. Using a ruler or other device, record the depth (position of piston at its max DOWN point and at its max UP point) of each piston and cylinder. Measure from the top edge of the cylinder to the top of piston. Do this for both cylinders and compare the depth figures. The cylinder having the lower value (shorter travel) will be the affected cylinder.
If you detect a "dead zone" of piston travel on BOTH CYLINDERS, that means BOTH connecting rods are likely burned up. In this case do the following. Turn the fly wheel until one of the pistons reaches the max UP point for that piston. When it is at max UP, measure distance from top of cylinder to top of piston (or mark the cylinder at the top edge of piston with a crayon or pencil) Next,turn the flywheel in the opposite direction until the piston "just begins to move". When this piston begins to move, stop turning the flywheel. Using a non metallic tool (hammer HANDLE, piece of broom handle, or a dowel), push downward on this piston (hold the flywheel stationary when doing this). The piston will move in the cylinder and then stop. Measure the distance the piston moved in the cylinder and record that. Repeat the steps on the opposite cylinder.
..........................................................
While each piston is in its DOWN position, inspect the cylinder walls. Are the cylinder walls nice and shiny, and smooth with a glossy surface appearance? Or are they full of rough, scratchy looking grooves that run up and down the cylinder walls? Do the above "tests" and report back with your findings.
..............................................
To respond to the post by johntommybob about the possibility of the starter causing the engine to "abruptly stop" when it is being turned. Consider that the drive pinion gear on the starter is very small and has few teeth compared to the engine flywheel ring gear. This means that the armature (rotor) of the starter must turn many revolutions in order to turn the flywheel one revolution. Conversely, when turning the flywheel by hand, one revolution (or 1.25 revolution) of the flywheel would cause the starter drive pinion gear to rotate many revolutions. If the "binding" or "abrupt stop" cited in this case were due to a locked up starter, I would think that the flywheel would be "un-turnable" at all. AND it would require that the starter drive pinion gear be "stuck into" the ring gear as well. Since the starter might be burned up (remember the smoke), it would not hurt to go ahead and take the starter off the engine anyway. I just don't expect to find the starter as the cause of the "abrupt stop" symptom seen here.

Ok. I just finished taking the heads off and going through the tests. It took a while because the results weren't expected so I did the tests multiple times and got the same results.

Both pistons move when the flywheel is turned in either direction immediately as the flywheel is turned. There isn't any lag that I can see anywhere. Both pistons also move the exact same distance, 3 and 13/32 of an inch. Both pistons also seem to "tighten up" between 1.25 inches and 2.25 inches.

When the pistons are in the down position, the walls are smooth but there looks to be some grooves. I'm not sure if they look ok or not so please check out the pictures and let me know.

I also put up some pictures of the Pistons at the link included. I included the "leaky" fuel pump also. I'm not sure of the pistons should look the way they do or not but I assume the crusted over black "soot" isn't good. Should that be wire brushed off?

As for the starter, The teeth from the starter don't engage the flywheel at all so I don't think that is the issue. I do think the starter will end up being replaced though because it just sounds like it gave up last week.

Here is a link that might be useful: Piston Pics

Photos look good. Components appear to be OK. From your description of the circumstances (especially the 1.25 turn and stop), this is not what I expected. It sounded like a textbook engine damaged, crank wiped out, rods wallowed and/or broken, pistons galled, cylinder walls scored badly kind of bad situation. The piston travel is right on the money.
Does the engine still make the phishhhy sound when you turn the flywheel? Does the engine still only rotate 1.25 turn?? Do the valves on each cylinder move when you turn the flywheel?? When you say "clean with wire brush", you mean a hand operated wire brush or wire cup brush in a drill? You can clean the top of the piston with a wire brush in a drill if you like. Don't use a heavy bristle steel brush for this, you don't want to gouge up the cylinder deck or the piston. You can scrape the carbon deposits off the top of pistons using a scraper or a screwdriver also. Be very careful not to dig into the piston or the cylinder block with the scraping tool. The cylinder heads can be cleaned similarly. You can use commercially available paint and decal remover to soften the carbon deposits if you like. You really don't need to begin cleaning up parts until we get to the bottom of the engine only turning 1.25 turns.

The "phishhy" sound is coming from the pump diaphram area. It also sounds like it coming out of the exhause valve on the right side BUT it was inconsistent and I may be off in hearing the exact location. Even after I drained the tank, there was still fuel being forced out of the fuel pump cover. I did disconnect the fuel supply hose to drain the tank so I know the fuel is not coming from the tank. Less fuel drained out after an hour of turning, but my arms started to get tired and it was late and my neighbors were getting upset. I'll try it again today to see if more fuel drains.

The flywheel still only turns 1.25 revolutions with the plugs out. Stupid question but since I don't know a lot about motors, are the piston both supposed to be in the same position at the same time? Both pistons are in the full UP position at the same time and then both are in the same DOWN position at the same time. I always picture the big block ford in my old mustang that alternated pistons and assume this would run the same way. I guess the 8 cylinder would run different than a 2.

The valves do move when the flywheel is turned BUT not consistently like the pistons. I'm not sure if this is by design, or if this is the first faulty part in this saga. For instance, the left side intake valve only moves with every other turn of the flywheel and the exhaust valve moves slightly after the intake valve. I should go back and document their movements better....

For the cleaning part, I was just going to do it by hand. I do have a drill attachment but I don't want to damage anything else by using it. The deposits pretty much flake off when I rub them with my fingernail.

***"are the piston both supposed to be in the same position at the same time?"***
On this engine, both pistons will both be at "mirror image" positions at any position of the flywheel (crankshaft). BUT....each individual cylinder/piston will be performing a different portion of the "4 stroke cycle" than the opposite cylinder/piston. This means that when one of the pistons is at "Top Dead Center" or "TDC" (max UP) on its COMPRESSION STROKE, the opposite cylinder is at TDC on its EXHAUST STROKE. On multiple cylinder engines, this relationship between cylinder "pairs" where one of them is in the compression stroke while another (companion cylinder) is in the exhaust stroke, is the basis for what is called "Companion Cylinder Pairing". In this two cylinder engine (461707), each cylinder is a "companion cylinder" to the opposite cylinder.
The four strokes of the "4 stroke cycle" are (in proper sequence) (1) INTAKE STROKE. During the INTAKE STROKE, The EXHAUST VALVE is CLOSED, the INTAKE VALVE is OPEN, and the piston is travelling DOWN. 180 degrees of crankshaft rotation & 90 degrees of camshaft rotation has been accomplished thus far. (2) COMPRESSION STROKE. During the COMPRESSION STROKE, the EXHAUST VALVE is CLOSED, the INTAKE VALVE, is CLOSED, and the piston is travelling UP. 360 degrees of crankshaft rotation & 180 degrees of camshaft rotation has been acomplished thus far. (3) POWER STROKE. During the POWER STROKE, the EXHAUST VALVE is CLOSED, the INTAKE VALVE is CLOSED, and the piston is travelling DOWN. 540 degrees of crankshaft rotation & 270 degrees of camshaft rotation has been accomplished thus far. (4) EXHAUST STROKE. During the EXHAUST STROKE the EXHAUST VALVE is OPEN, the INTAKE VALVE is CLOSED, and the piston is moving UP. 720 degrees of crankshaft rotation & 360 degrees of camshaft rotation has been accomplished.
In a 4 stroke cycle engine, the camshaft rotates at exactly 1/2 (.5 or one half) the frequency (rotational speed or gear ratio). Whatever you want to call it, it requires 2 turns of the crankshaft for every one turn of the camshaft to complete one "4 stroke cycle". To express this concept yet another way: The crankshaft must rotate "720 degrees of a circle" (2 revolutions) in order for the camshaft to rotate "360 degrees of a circle" (1 revolution). What each indiviual cylinder is "doing" at the moment can be determined by observing the position of each valve for a given cylinder. On "flathead" engines such as this one, it is easy to observe the motions of the valves as they are still visible when the cylinder head is removed. OHV configurations are more "challenging" to observe when head is removed be cause on those you must "watch" the pushrods or the camshaft lobes directly. Because this particular engine will only complete about 1.25 turns of the crankshaft (450 degrees of crank rotation), it is beginning to look like the problem of "abrupt stop" is due to something wrong in the camshaft gear train or other component related to the camshaft/valve train. I'm out of time for the day (again) but will get back tonight or tomorrow. In the meantime, if any of my "brethren" wish to "throw in" something, please do. That is a "request", not a "challenge"

Just to make sure that the "1.25 turn" of the crank/flywheel is actually "inside the engine", check the crankshaft PTO end (under tractor) to confirm that nothing about the clutch (if electric PTO) or deck drive belting is causing the binding or "abrupt stop". If you don't find anything "wrong" on that end of crankshaft, the next move will be to "pull the engine" and look inside it at the camshaft gearing and stuff.

Update. I ran in to an old friend that is a mechanic. He offered to take the tractor and tear it down with his class (he teaches small motor repair). The good news is it is really cheap (I only need to pay for parts they don't stock) for me but it may take a little longer. I'll be sure to post the results they get as I get them.

I'll be interested in learning what caused the "only 1.25 turns" of the flywheel. So be sure to ask about that and listen closely to his explanation. You are fortunate to have come upon this "windfall opportunity". Make it "worth his while". He probably can't accept payment "personally", but you might be able to contribute to a "petty cash" fund for the class room expenses if that is permitted.