3020 Gasser Power Loss

I need ideas on 3020 with loss of power. Early 3020 Gas, electronic ignition, oil bath air filter, power shift, 1500 hrs approx., zenith carb. Got it last year, and seemed to lose some power on hills o way home, but now has gotten worse. Starts, idles OK. Does not have enough power to go up a small rise in high gear, loses almost all power and then will not even get up in RPM in neutral. If it does quit, it will start OK wiethin a minute, and can reproduce the problem. It can Pull a 12' disk in 3rd, but still loses power on hills and dies. Seems to be similar in warm and cold temps. My first thought was no fuel. Then not enough air flow.

Replaced gas pump. (did not feel cam lobe for 'bump' though, but verified valve lifters all working OK and verified clearances), oil in air filter is clean, engine oil pressure at 40 psi. Removed aftermarket fuel filter and blew gas lines out with air, gas flows freely and no 'gunk' found. Drained carb and no visible gunk. Choke appears fully open, and no interference in controls.

Pulled air filter canister off, and I seem to be able to 'blow' through it with no back pressure.

Pulled the top off of the distributor and I can turn it abt 10 degrees counterclockwise (verified the ignition advance is not locked). Wires are resistor wires. I have dist cap, rotor, and wires ordered, and just put new plugs in.

What should I try next? Send carb in to rebuild? Ignition overhaul and repair all electronic parts and coil? Governor?

I would offer a reward for the answer if I could!

-Lyle

Have you opened the fuel tank drain to check for any water?

Is there any debris in the tank that could be blocking fuel flow as it moves around up and down hill?

Have you drained the carburetor and observed what came out (any water/rust/sediment?)

Opened fuel petcock and no water. Drained carb and looked OK, no water or bad stuff. Blew out gaslines from fuel pump (replaced) and had good air flow. No change.

Thanks for the suggestion.

timing?

I have not checked timing yet. I did not touch the distributor / loosen it.

Needs a good old fashioned throttle wide open compression check, without first and then with oil for two readings per cylinder. Start there, post results and it might help bunches. They do get old and tired, this will eliminate that issue from the possibles or point right at an overhaul.

Definitley check the timing. Even a tired engine should rev up under no load.

When it quits, do you still have a spark at the spark plugs? Does it run better with the choke closed a little?

If I'm reading correctly you have good power while flat and no power on hills? If so you most likely have a bad float / hanging / set to low or something rolling around in the tank.

Id start with the carb.. easy to rebuild with kit y ourself... then work from there.. I have a 3020 gas.. rebuilt the carb twice since I have had it.. Also check out your fuel pump and replace fuel filter.. Also mine ran like crap with champion plugs.. auto lite is all I use in mine.. my two cents.. Good luck..

What symptoms were you seeing that made you repair the carb?

I should have the timing checked and the compression tester this weekend.

Mine would idle fine..putting it under load would studder and loose power.. let us know on here what you find out..

I might ad that when I first had this issue years ago I replaced plugs, wires, dist.cap, rotor, etc to no end.. then cleaned carb.. bingo.. ...just letting you know what I encountered..

Something is definitely not right....I have a 65 JD 3020 gasses and it is very stout. The only issue is the carb will load up a bit if I let it idle too long. I also rebuilt the carb as soon as I got it and I have had good result with the rebuild. My fuel pump was toast so I replaced it with a new one and filter...did a pressure check to be sure it provided good pressure. You are on the right track to check engine compression, timing, spark, change out spark plugs (use AC's) and wires etc. I removed my air cleaner canister and spent a lot of time flushing it out with diesel fuel as it was very dirty and the oil bath was full of water and gunk. I would recommend disconnecting the inlet air hose to see if that improves power. You could also send in an oil sample to check for metal contamination to be sure something is going bad with the bearings. I know you checked the valve clearances but did you check the camshaft lobes for proper duration/lift. Good luck.