Repaired 8N stalling when trying to open up the throttle (yes, me again)

[PorkChopsMmm]

OK, I have some progress -- nothing great but finally getting somewhere.

I followed this How-to for checking the governor and found this out (my responses in bold)...

14. Think you have governor problems? There are three ways to check to check the operation of the governor. Get the throttle lever at its lowest point (engine idling) Then, start tapping the throttle lever slowly open. How far does the throttle move before the engine speeds up? Lack of low speed throttle response (like about 1/3 of the throttle) is the classic symptom of a bad or out of adjustment governor. The tractor instantly starting changing RPM with the throttle being moved.Next test, put it in gear at about 1/4 throttle, put your foot on both brakes & let the clutch out. The engine should throttle up as the governor arm opens the throttle plate in the carb to compensate for the load on the engine. Engine tries to increase RPMs very quickly but engine stalls. Next test, with the tractor running, pull on the rod going to the carb; does the governor pull back? Yes, and RPMs adjusted accordingly. If that does not work, get out the I&T FO4 manual & check out the 'adjusting governor' paragraph. Finally, before I paid $200 or more for a governor, I'd pull it off & open it up. It could just need new balls & races. Have not done this yet.

Also, while it was running with the throttle at low idle AND at high RPM (sputtering, not sounding great) pulling out the choke would want start to kill the engine at low idle and reduced the RPMs/made it sound like it had even less power at high RPM. So it looks like pulling out the choke doesn't help anything.

Here is a YouTube link I took of the tractor a while back:

 

[tyler1921]

Did you check the points yet?

 

[Egon]

Have you got any water in the carb?

 

[PorkChopsMmm]

I will try and check the points tonight. From all likelihood it sounds like my points gap could have changed or the points could have been corroded.

I doubt the carb has any water in it as I have drained the carb since it started causing this problem (to make sure gas flow was good) and the behavior did not change.

 

[8N Ren]

Mine was doing the same thing 3 weekends ago, I had a set of points in my tool box and swapped them out. Bingo bango she was running fine again in a matter of minutes. The worst part of it was the temp sitting at -35°C with a nice north wind.

 

[PorkChopsMmm]

OK, it wasn't points. They looked good but I cleaned them anyway. I took a video of what I found -- the governor seemed to be the issue. Check out the video -- the governor was randomly moving the arm back and forth as the engine was running poorly. When I manually pulled the governor lever forward (towards the front of the tractor) it ran better.

So... consensus on the governor?

 

[Soundguy]

if the engine tries to stall.. the gov should try to snatch carb open assuming you have throttle set high enough.

as for the springs.. no slack or preload.

 

[PorkChopsMmm]

OK, I took off the governor and all looks good. Only one large bearing had the start of a flat spot and none of the others did. The races were not worn down whatsoever. My governor looked almost new inside compared to some of the "how to" rebuild pictures are available on the internet. I put the governor back on and fired her up -- no difference at running above half throttle.

Soundguy -- I went back to what you said about spark being the first thing you check. With the throttle at 3/4, so it would be stumbling, I took off each spark plug wire and tested for spark (they all did have spark). But I noticed when I took off #3 and #4 wires that the engine stumbling did not change -- it was stumbling the same way with the wires on or off. The spark plugs were new as of last March -- maybe they are coated with carbon... or maybe I have dead cylinders? Last year when I ran into so many issues I checked compression and all looked good.

I don't have a good wrench for getting under the gas tank at the spark plugs so I will try to pick one up tomorrow. Besides pulling the plugs and checking for carbon or soot that would make them not spark well... any other suggestions?

 

[8N Ren]

A combination wrench fits better than a spark plug socket IMHO.
I could be off base but do you have the right firing order?

 

[PorkChopsMmm]

It was in the right firing order when it was running well and while riding it it stopped working well, so I didn't think the wires were switched at some point. When I checked the points I double checked the wiring -- it checked out. I have the wires labeled.