9n propane converted

My 9n is propane converted. Not an issue I have a tank and a wet
line and got a crash course when I bought it as to how to fill the tank
and not do anything dumb.

But, my tank is on the grill (100 gal tank) and it was brought over on
the Mayflower. Unfortunately, the tank is leaking when its on or off
from the valve where you turn the gas on or off. It has a weird type
plug in that goes into the valve - much unlike a modern tank which is
a ton easier to fill. This one fills from a separate valve than the
outgoing line and has a hard to reach and twist release down on the
side (not the screw type the new tanks have)
I have the distinct feeling if I bring it in theyre going to tell me they
cant fix that or that its outdated and no longer serviceable.
Im ok with that, Im happy to buy a modern tank. I am, however,
stuck on how to repair this? This outgoing line that goes to the
vaporizer goes into the valve not like a modern tank.
Can I convert this set up to a modern tank? How do I find out what
size regulator it requires? Most of the lines Ive checked out are for
grills and I have the idea that a 30 psi isnt going to be enough to fuel
a tractor.
Not sure where to even start on finding correct parts here. Im
mechanically inclined enough to understand how it works basically.

Other consideration here is sometimes it gets doggy and will stall,
mostly in the higher gears (3rd) and will stall if you put it into road
gears on the aux even in first. This leads me to think its either
flooding or starving but Im not sure which - guess is fuel starved.
But I dont know how to adjust any of this crap and I dont know
anyone who does either.
I prefer to keep it propane converted because it runs clean (spark
plugs and oil are pristine) and cheap.
Thanks in advance.

Talk to different LP suppliers, maybe they can point you to someone familiar with LP systems that can help you out. I would think you would have better luck at a farm coop that supplies LP than Ferrel gas or some place like that, but try them all, Lots of industries use LP forklifts, etc. Has to be someone that services them.

A cooking grill uses vapor drawn from the tank so it is likely you are right, the parts are not the same. You say your tractor has a vaporizer. That sounds like it is a wet draw system, the propane is liquid until it reaches the vaporizer. If it is, you would need a tank with a wet draw. Forklifts, welders, aerial lifts use wet tanks, but most of those are portable tanks that get swapped out when empty. You might check with dealers of that type equipment (along with your propane supplier) as they may have sources for different types of wet tanks. Just my thoughts, based on my understanding of what you described, which could be wrong.

Look online for propane engine fuel systems.

There are companies that supply replacement parts and complete retrofit systems for all kinds of vehicles and equipment.

I'm sure they will have someone in customer service that can walk you through this.

Another option would be to convert it to gasoline. Unless you just want to keep it propane, that may be the more economical option.

My propane tractor starts on vapor and runs on liquid. It doesn't get enough fuel on vapor and won't pull worth a hoot. Switch to liquid and it works fine.

Definitely has a vaporizer, big round part the hose goes into with a
bigger line (maybe 1/2) and comes out the bottom with a 3/8 line
then to the carb.
Wet tank you say? Maybe thats why it looks so different, has 3
valves on top, one I can fill, one thats hooked to go to the vaporizer
and some other crap.
Only date I can find on the tank is 4/50...so guessing that was its last
cert date...lol.

Reverting to gas wouldnt be so bad if the original fuel tank was in it
still. The gravity bowl is and everything else...but I have no issue
filling with propane. Main reason I want to switch it out is the gauge is
busted on the line from the tank so you always have to guess how
full the tank is, generally since it has that leak, that means Im on the
back 40 when it runs out and end up walking. Typical Ford, thats why
I drive Dodge pickups.

Look closely around the fitting ports on the tank and see if you find any stampings. The Liquid draw port will sometimes be marked, along with the other ports. I would say that is a liquid draw/wet system. A shop that works on forklifts or aerial lifts would be a place to start to find a mechanic familiar with that type system, as those often use liquid/wet systems. They generally use smaller tanks that get exchanged when near empty, or run out at the worst possible time and place.

Appears the loping and running like crap can be attributed to the points. Im about to have a learning experience as the last time I remember seeing anyone work on points I was maybe 5 (so 1990ish) and my uncle did them and caught his finger in the fan blade messing with something to do with them.
Wanted to blame it on the propane system but after trying to get it started repeatedly I went back to what would I do if this was gas and not starting and found I had no spark at the plugs.

If you pour hot water on the tank and then run your finger down the tank, you can feel where the propane level is, because it will be cold.

I have a combination pressure regulator/evaporator that was new in 2018 and used 3 months before removed.It's not quite as large as regulator pictured and can be mounted in same place. I will take $75 plus shipping for it.
Has the tractor ran well for you in the past? For how long? I don't see anything unusual about filler or valve supplying fuel to regulator. I would think the valve is replaciable and/or can be rebuilt. By rebuilt,I mean new stem packing (I believe seat is brass on brass which should never wear out}. Does the valve not screw out of tank?
What I do see that is strange is lack of vapor supply. The valve with nothing hooked to it is probably vapor withdrawal. I've see hundreds of propane tractors and every one of them start on vapor and run on liquid (although tractor can be run for hours on vapor in warm weather.) The outfit you are buying gas from should be helping you through this or telling you who can. Getter firing and let us know if that fixed it.

Coil is dead and condenser was bad for sure. Reeks of burned electrical when I took it off. Points look good and gapped at .015 so I left that alone.

It has always ran like a champ until the last couple of weeks. Found. I have no spark when I finally just decided to treat it like I would a gas motor and ignore that its propane.
Started running doggy, loping along instead of running normal, no power during the snowpocalypse - fired right up but acted like it wasnt fueling correctly, would stop doing it if I shut it off and restarted. Ran pretty decent, enough to clear my driveway enough to get the pickups out of the drifts.
Left it alone. Hooked the disc plow to it yesterday, ran it a few loops and it sputtered a bit then stalled out. Figured I overloaded it a bit, started back up and it ran like crap and would go maybe 5-10 ft (plow lifted) and then die again. Got it up to the tank, topped it off, and didnt start.
Replaced the condenser and determined coil is bad. Just got the coil and hoping itll fire up.

New coil, new condenser and it fired up. Still running doggy. Decided again Id treat it like a gas motor and thought Id mess with the carb a bit. Figured out how to step up the air/fuel ratio (not entirely sure what I did there Id I increased air or fuel but that adjustment is on the LP line just before the carb - stalled it a couple of times before I figured out the sweet spot) and it started running really nice. Readjusted the idle a bit after adjusting the air/fuel ratio and ran it for 2 hours solid with the disc plow, tore in an entire arena beautifully without a sputter.
Something isnt quite right. It wasnt easy to get started, though Ill admit once I got it started and adjusted I didnt shut it off to try it again because I had stuff I needed to do 2 days ago and rather than keep playing with it I was going to get it done first. I had to choke it to start, and it isnt cold here, it was in the 70s yesterday. But as soon as it fired I could reduce the fuel lever and push the choke back in.
Carb might need a rebuild 🤷🏻‍♀️ It is the original carb for sure, Im not sure how/if/when it was upgraded for LP.