720 LP. Not starting

I have a friend that bought a 720 John Deere LP. Someone had been into the engine to retrieve a bolt from the throttle body butterfly. After they put it
together it would pop back through the intake. They let it set for several years before my friend bought it.we found a bent valve and fixed that. Lapped
the valves, replaced intake and exhaust gaskets and two broken bolts. We set the valves and checked the timing. Points set at 0.020. Plugs at 0.030.
Spark at the end of compression stroke on left and right cylinder. The regular will dispense propane vapors in the intake and throttle body. Idle needles
set at 1 1/4 turn. Load is set at 3 3/4 per the manual for Gar and LP John Deere manual. We can Not get a hint of a bark out of it even when we belted it
to a 620 LP. We changed plugs and condenser from the running 620 to the non running 720 LP. The 620 fired up. The 720 still no fire. I have checked
everything and I must be missing something. I have pulled my hair out. I even pulled the spark plugs and poured some gas in the cylinders to just make
it try to run. No Joy I need some ideas. Someone before had the distributor out by two teeth. It is back in time. Any Help would be Appreciated. Thanks
in advance

Do you have the oil cup on the air cleaner? My father in law fought a 730lp that wouldn't start, put the air cleaner back together and it started right up. Apparently with the oil cup removed it couldn't draw fuel correctly.

(quoted from post at 20:29:52 10/09/19) Do you have the oil cup on the air cleaner? My father in law fought a 730lp that wouldn't start, put the air cleaner back together and it started right up. Apparently with the oil cup removed it couldn't draw fuel correctly.

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This. Make sure the cup is on and full of oil to the proper level.

Thanks will try that. We had the air cleaner body removed.

Thank You. We had the air cleaner canister totally removed. I will re install it and fill it with oil.

the very first thing is make sure you are getting fire. Second make sure you are getting fuil,don't trust the gauge on the dash, most time they don't work, read about lp if you haven't ever had one. Get a owners manual.Do you hear a click when you turn key on if not it will never start must hear click. if you do take fuil line off and make sure fuil is getting to converter. If all this is happening look at back of converter you will see a hole with fuil on and key on take a blunt object and easily push and you should hear a his of fuil. If you hear bubbling in radiator you have a bad diaphragm in converter. And make sure you have radiator at correct level.

Thank You Rick. We have checked all of these things and I have followed the manual to a Tee. I removed the distributor and disassembled it and cleaned everything inside it. Even the centrifugal weights. There was a lot of rust down deep in the distributor. I cleaned the points plate and wiped it down with Alcohol to remove any oils that might not let the points ground good. Put the distributor back it. Check again that the flywheel was on left TDC. Turned on the switch and adjusted the distributor to fire on TDC. Tried the starter and no joy. Plenty of fire at the plugs. After 30 more min. And nothing. We decided to belt it up to a 630 LP. It did not turn over three complete revolution and it came to life. We ran it for 10 min. And killed it. Tried the starter. It rolled over for 30 seconds and did not start. Belted it back up and 2 complete revolution and it was purring like a kitten. We then let it idle for an Hour and a half. It never skipped a beat. The starter will not turn it fast enough to get it to start. We are using a toggle switch and a direct wire from the battery to the toggle switch to the coil and to the solenoid on the regulator and from the coil to the distributor. The other wiring is totally messed up. A rewire is next. Thanks again.

my number is 870-919-2212 I have several lp tractors