Generic gasoline engine tuning question

[carpenter383]

If the stumble is improved by choke then it's definately a lean condition. Have you checked for vaccume leaks? Also make sure the float bowl is vented to atmospheric pressure or the venturi effect won't be on your side Typically there will be a hole in the air filter side of the carb which leads to the float bowl.
Also be careful with that electric fuel pump, you may need an adjustable fuel pressure regulator ($30 bucks at most auto parts stores) to keep fuel from pushing past the needle and seat.

 

[284 International]

Carpenter, I put a low pressure adjustable regulator onto the already low-pressure pump. So, thanks; I have it covered.

I should have been more clear, as well: pulling the choke only helps after initially opening the throttle, basically to cut off the air supply and richen the mixture for a short period. After a short time (less than 2 seconds) having the choke on makes it run worse and/or die. So, it doesn't run better with the choke on (In fact, it won't start or run if I use the choke at all) except for very briefly if I open the throttle to wide openings.

I have neglected to check the float bowl vents and their affiliated vent lines. I'm going to do that right now. Thanks.

 

[chance13]

Hello! Had just bought a 284 and had the same problem. replaced with new plugs and wires. Still stumbled. Firing order is 1,3,4,2. Install from #1 on distributor 1,3,4,2 it may solve the problem.

Hi, I have a gas IH 284 that really lacks power. When it attempts to pull a load (even starting itself out with no implement or trailer) the engine bogs, stumbles, and runs roughly. With no load, it runs smoothly, but it is difficult to throttle up: opening the throttle, even with no load, makes it stumble.

I have replaced the spark plugs and fuel filter. The spark plugs were sooty and dark black (including the new ones after less than an hour of use), and the fuel filter was free-flowing. I have replaced the air filter, and even tried it briefly without the air filter, all for no change.

I'm sure these symptoms mean something to someone with more knowledge than me, but I'm out of ideas. What should I try next? Thanks in advance.