Fuel/Timing

[JB1987]

Hey everybody, I'm new. Looking for some help with my 184 Lo-boy. I'll start at the beginning.. I had to put a new seal in, so it was parked through winter time and torn down. Everything went back together fine. We didn't mess with any timing or internals. I rebuilt the carb, put a new sediment bowl on the bottom of the tank and cleaned the tank best I could. It started up fine, but it died at random, and wouldn't throttle up. Then I couldn't get it started back, had to pull it back to the barn. I have 2 carbs, so I cleaned the other and put it on. Checked everything again and started it up. Runs exactly the same as it did with the other carb. If I try to throttle up it sputters terribly and will rev up and down, and it sounds like it's losing fuel. I gapped a new set of plugs and put those in to see if it made a difference. No difference. I went back to my fuel supply, drained my sediment bowl and made sure there wasn't an obstruction. Hooked everything back up, started it. It starts and idles like it did before, and I can't get it to hold full or even half throttle. It will either run for 2 minutes or 20 minutes. Every now and then it sputters while it's idling but for the most part it is smooth. Still won't throttle up and stay, the more fuel I try to give it the worse it runs. Any ideas? All help is greatly appreciated.

[JB1987]

It sounds like timing.. but it got too late before I could check that.

[mozer71]

There are folks here which will blow me away with advise: -but- When I purchased my 154 it ran enough to get up the ramps into my truck. I spent some time rebuilding and straightening the 3160A deck, so it set awhile. I did all the normal things we do when we get a new machine. Plugs and Investigating each plug. Each one holds a clue. From there, investigating the distributer/ rotor / shaft play /cap and resistances.
Cleaning / as required and getting into the carb. Verified the static timing and reset the dwell. Replaced the weak coil..
Here's the deal; These engines continue to run with all manner of issues. Weak connections, bad gas etc. All these things have been adjusted by somebody else, to keep it running. When all is done it idles about the same as it did before. Then it is the governor.

[mozer71]

Well I better say it. This was not complete advise. It took only a few minutes to find much more and specifics in looking at these topics.
No harm intended.

[JB1987]

No worries, I hear you. I just feel like I'm missing something. I worked and stared at it so long.. I felt I needed an outside opinion ha ha.

[Landreo]

Although you said you did not fool with the timing, I would double check the advance. You can check with a timing light or just try to twist the rotor and see if it's stuck. Double check the firing order.

[mozer71]

You will find better advise as you search here. These tractors are so old (timewise) that recommendations from 15 +years ago are still true. We like real- time replies, I know I would have. By looking at the information here, I display some ignorance by the recount of work done blind 15 years ago.
These tractors are nearly fresh as before when set right. There is ignition for idle but a strong spark required for higher concentrations of fuel/air mix at the right timing. The other thing is Clean fuel. There are a few places which sell fuel without ethanol. The proper additive can lubricate the valves stems. I always like to do a compression check and see what I'm dealing with. Mine wasn't bad 10 years ago.

[Steve Butram]

You may have a valve hanging open

[outdoors4evr]

After you verify the timing at an idle and at wide open throttle (full timing advance), go back to the carb.
The air/fuel mixture is adjusted by the air adjustment on the top of the carb. This is a very sensitive adjustment on the carb and really affects how your engine accelerates and idles. Remember, this adjustment is an Air Adjustment. As you back it out, you are allowing more air into the carb which leans the fuel to air mixture. Out = Lean (less fuel), In = Rich (more fuel)

Thread it in all the way (gently) and then back it out 1.5 turns. Then adjust it in or out as needed until the engine idles decently (1/4 turn adjustments). Then try to throttle up the engine. It will probably stumble and try to die as it is accelerating. Go back to idle and adjust in or out in 1/8 - 1/16 turn adjustments until it accelerates without stumbling.

There is a very fine place where it idles (albeit somewhat lean) and still accelerates without stumbling. This becomes very important when you are trying to spin up load like a mower deck. You don't want it to stumble under a load.

[Gary Dotson]

I've also seen a bad condenser give the symptoms you describe. I would probably look closely at the distributor, improper point gap can act up like that too.

[JB1987]

Thanks alot guys, I appreciate the good advice. I'm going to see how it goes today.

[Larry B]

My money on fuel or spark. Things to try.
Pull plug wire test that ignition can jump a 1/4" gap with a blue spark. Test all 4 plug wires. If so ignition will run engine at full throttle
Be sure static ignition timing is set properly. Even if advance is not working it will not cause surging.
Remove fuel line at carb and check for good flow for a couple minutes and remove any fuel filter.
When engine starts to stumble does pulling the choke help? If so fuel prob.
If you have the Zenith carb remove the main jet at the bottom of carb and check for good fuel flow. Be sure the hole in the main jet is absolutely clean.

[Landreo]

My money on fuel or spark. Things to try.
Even if advance is not working it will not cause surging.

I chased a similar problem years ago with a 185 with stumbling and surging. . Pulled the carb many times since I was convinced it was a fuel problem. It ended up being a stuck advance weight. Anything that has a different effect at different engine speeds can cause surging. I would put a stuck advance low on the list of things to check but certainly a possibility.