4400 gas combine engine

Have a 4400 gas combine with 292 chev engine. Seems to want to spit and sputter under load and has a miss when you try to open throttle fast. I have already: cleaned fuel sediment bowl and checked fuel flow from tank/ and line up to carburetor. Installed new plugs-old ones were quite white in color/running lean. Installed new points-old ones were worn enough to warrant replacing. Carb....is a zenith, and from what I can see only has 1 screw for any adjustment. I can turn it in tight, changes nothing. Only time it changes amything is when I turn it all the way out so it falls out then the motor starts to die. Further suggestions? Thanks.

Mine had a filter where the gas line attached to the carb, kind of a disk separator affair....Ron

Did you install a new condensor when you installed the new points? Is the advance mechanism siezed?

yes, new condensor.

I once bought a pristine 4400 gas combine for cheap as the owner couldn't get the engine to run at full throttle. He had a 8820 and was getting a another new combine so he just wanted to get rid of it. I drove it 20 miles to my farm with it having trouble getting up hills and no brakes. Had to go through town with 5 traffic lights. Had to drop header to stop but got it home. Did all the things you have done and no help. Happened to crawl into the grain bin and noticed the air filter in the bin had broken bands holding it in the cradle and the air hose to the carb was crimped. That was all was wrong with the engine. Replaced the bands and she ran great for 15 years until I sold it for 3 times what I paid for it. Recommend you take the air cleaner hose off the carb and see if it helps. If not, suspect carb needs rebuilt, retime or rebuild the distributor, replace the plugs and wires, not necessarily in that order. How old is the gas???? Might throw some Sea Foam into the tank and check the fuel pressure at the carb. Chevy 292's do not run very smooth, run hot, and suck the gas but they are very dependable in the long run. Good luck and let us know what the fix is when you get it running good.

Back in the day when there was allot of these Chevy engines in use on the 4400’s it was not uncommon to have to replace the distributor as it became so worn in the shaft bushings it would not run right now matter what you tuned on. I had replaced many in the late 70's and early 80's.