I will start by saying I am a diesel guy and no next to nothing about car stuff. My combine has a 225 engine in it. The fuel pump is electric next to the fuel tank at the back of the machine. I have owned it for three years and every time I have to shut it down after running it has to sit for like 1 to 2 hours. Then it will then start right up. The thing runs amazing otherwise. Only when I have to shut it down hot, I have issues. It has the heat flap in the exhaust that I have read about. I have seen a couple things about using a vapor fuel filter but have one the one fuel line in the gas tank. Is there anything that can be done to these to help with the issue?

Would you mind uploading a picture of the fuel line routing to the carb? There is a revised routing on normal passenger car slants that helps with the vapor lock issues. It has been so long since i thought about it I don't remember which slants it applied to. How tight is the cowling around the engine for retaining heat?

Probably not vapour lock—that really doesn't happen in a system with a pusher electric fuel pump. Don't throw guesses at it; what's needed is careful diagnosis to figure out what's going on. First step: figure out if it won't start because it's flooded/getting too much gas—engine bay stinks of gasoline especially if you take off the air cleaner and put your nose in the direction of the carburetor—or because it's starved/not getting gas—when it won't start, remove air cleaner, look down carb throat, operate throttle, and watch for gasoline shot from accelerator pump. Or if it's an ignition issue mimicking a fuel issue (coil, distributor pickup, or ignition module, as applicable, failing with heat soak).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I my phone won't upload pictures right now. The fuel line comes straight up from under the oil pan. The engine has some room around it but not a whole lot.

I am just going on what a couple car friends have said. st two years I could smell gas the last two years. This year I didn't smell any. I have owned it for three years so I have no knowledge before other than it sat for 10 years before me.
The one thing that I do notice is that when I try to start it hot the engine cranks over for a couple revolutions then acts as though the battery is weak. Same even if I try jumping it.

They've almost certainly got it wrong. Which is fine; "Won't start" has many causes, and so it usually cannot be diagnosed by conversation.
What we need to know in order to help you is the details of what it's doing and not doing now. Like: when you try to start it hot, and it won't start, do you smell gasoline in the engine bay?
That suggests the engine is fighting against the starter, which is usually do to badly-improper ignition timing (spark happening much too early). Set up the conditions to cause this symptom, then pull the coil wire (the one that runs from the coil to the middle of the distributor cap) out of the distributor cap—pull by the boot, not by the wire, or you can ruin it—and tuck the end of the wire somewhere within about 1/2" of grounded metal. Now go crank the engine; does it spin over normally, without the weak-battery sound effects?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I will work on it this weekend and see what I can find out. If the spark is that advanced would it start as good as it does when it's cold?

This kind of abnormal spark timing is usually caused not by maladjustment, but by one or more faulty components—distributor cap is at the top of the list, followed by the spark plug wires and the rotor—allowing spark energy to travel an unintended path and reach the wrong cylinder (the right spark timing for one cylinder is wrong for all the rest of the cylinders). And yes, it can happen only when hot…or only when cold…or only when the humidity conditions are just so.

Annoying though it be, it probably won't be very hard or costly to fix, and you've got an opportunity here to expand your knowledge beyond diesel engines. The Slant-6 is an especially good kind of gasoline engine to learn on.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

So I finally got time to work on it today. I pulled the wire going to the distributor when it was hot. That didn't change anything. No gas smell either. I looked in the carb and there is no pooling of gas.

Okeh. Just to be clear, what's happening is when it gets hot the starter drags slowly, like the battery is flat? Barely turns over the engine, even if you add another battery?

Is there ever a case where the engine will crank at a normal speed, but just won't catch and run? Or is the "no start when hot" always due to slow/no crank?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yes when it gets hot the starter drags slowly. I have hooked up my tractor and my works truck/ Both have two batteries and it will not ever spin faster. It never spins normal speed after it's warm. I have only maybe had twice wen messing with it hot where it made two normal speed revs when warm.

Okeh, then since we've eliminated crossfire causing the engine to fight the starter, this points at the starter. "Works when cold, drags when hot" is a common failure mode for starters of this general type—it's a winding fault (internal short circuit when the windings heat up). Next step is to replace or rebuild the starter. I thought I remembered you posting pics of this engine, but I don't see them now. It might be easy to buy a replacement starter off shelf, or you might have to seek the services of a rebuilder. Please post a clear pic of your starter to show which type it is.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I have tried uploading pictures but didn't have luck getting them to work. I will get pictures tomorrow and try again.

A few years ago I was helping a friend with a small farm, he had a MF 300 combine with a slant 6. At the time it hadn't been started or moved in 5 years. It was kept outside, not covered or anything. I started to help him work on it to get it going again. Probably a big part of that was it had a slant 6, my first car ('65 Polara) had a slant 6 and I rebuilt it once so it was cool to work on one again.

First thing with the combine is that I ran a new gas line from the tank to the engine - the existing line was plugged up, it was easier to just run a new hose. The tank is somewhat far from the engine. It has an electric fuel pump near the tank, there might have been an electrical issue with it but it was still working, maybe the wire connection needed to be cleaned up. This was an early 70's combine if I recall.

Naturally I changed the oil and checked the plugs before even trying to start it. I don't remember if I put new plugs in. I certainly checked the resistance of the plug wires to see if they were good or not. We got the engine going without much of a problem, I didn't like the carb (it wasn't a BBS like I'm familiar with) or the various linkages and govenors controlling the carb, trying to get a slow smooth idle was somewhat difficult. Maybe it's today's gas.

Beyond getting the engine running the combine had a couple of major problems. First was the drive clutch was rust-frozen. I made a puller out of 1/4 inch steel plate and was able to pull the clutch off, all the springs were busted and the disks were shot. Bought new springs (custom orderd from a place in california based on my best ability to measure them), was able to buy new disks from a place in northern Ontario. (this is all happening on a farm in SW-ontario). New clutch bearing also.

We (I) thought our problems were over with the rebuilt clutch. But we ended up messing up that clutch bad trying to put this thing into gear and move it. That's when I found that the brake (the brake operates on the right-hand-side front tire) was also siezed up. The left from tire we could spin when jacked up, but not the right. That's about as far as we got with this thing. The hydraulics worked and the cutter head could be raised and lowered.

During this effort I bought a new drive clutch with springs and disks, I still have it, it's available if you want it.

As to your problem that you can't restart it after it's been running and warm, I would say try this next time you're in that situation:

a) take a spare spark plug, doesn't matter what it's from as long as it's clean and you know it's a working plug, disconnect one of the plug wires on the slant 6 and connect it to the plug, hold the plug by the wire boot and press the ground electrode to the engine, some clean piece of metal or a bolt head while someone is turning over the engine. You should see a spark from the plug. If you don't see a spark, then you know where the problem is. If you see a spark, then

b) get a spray can of starting fluid and give a few shots of it into the carb or air cleaner (with the combine I'd take the rubber hose off the carb intake, shoot some fluid in there and put the hose back on). Then try starting it. It should at least kick a few times.

Be careful with those old combines. Keep a fire extinguisher in the cab.

Mine sat for 10 years before I got it 3 years ago. Thing always started up great when cold and idles amazing (I think for an old gas) I have a few YouTube videos of it (WSORfan is my username). I think we may have figured it out to be the starter as it is reman and got the info to get a gear reduction starter for it. I am also running new battery cables this winter. I cleaned it up this last weekend to put it away for the winter but it would start. Found the diode for the coil bad. Its now tucked away until I have some time to mess with it. Also my clutch was all rusted up but I was able to get everything cleaned up and only had to replace the bearing. I also have a few hydraulic leaks to fix and yes I keep an extinguisher handy. The lucky part for me is I work for a Massey dealer and surprisingly Agco still has quite a few parts available for it.