Hi folks,

I've been playing with my tractor a little here and there and the pony has become decidedly weak. It starts well enough. One or two pulls and runs good at first but when you crank the diesel is begins to struggle. The other day it couldn't pull it under compression and it would bog down until it would stall if I let it.
The mag seems to be ok. It's an Eisman and I set the point gap to .020" as per spec. I didn't do the other adjustment that they ask you to use a test light for but I checked timing in place and the line matches the middle of window. Also, if I hold the lead 1/8" from ground it has no problem jumping with a nice whitish spark.
Today I pulled the carb off and gave it a quick clean up and I did get the diesel started but it definately didnt have any snap to it. It is boggy even without load. It doesnt pull to max RPM quickly even when disengaged. Before it would pull the diesel under compression effortlessly right to rated rpm even without max throttle position. I put a small drill bit through the passages in the bowl about a month ago but perhaps some more munk got in there? I'm thinking to pull the carb and do it again.
Any thoughts on anything I should look closely for?
I like that I'm getting fluent at removing the carb but I think I should move onto learning other parts of my tractor ya know what I mean?

are you finding much junk in the carb? do you have an inline fuel filter before carb....because you should find very little to nothing after a couple cleanings....

-what do the spark plug(s) look like? should be a tan colour, maybe darker....brown etc...on the porcelain...and thread base of plug...

-i would try closing up the point gap a couple thou....say to like .018"...see if that helps or does what....if it does...try reducing another thou...to like .017" etc...i think the point gap is the fine tuning of the spark advance...

-you need to be extremely careful when putting drill bits thru carb passages, you do not want to change the fuel/air metering....

-also double check the spark plug gap....probably doesn't need to exceed .020"

-if there is any doubt as to age or condition of spark plugs....replace...really eliminates a lot of headaches and pains..

Sounds like it may be starving for fuel. Make sure the fuel is flowing to the carb by disconnecting the fuel line at the carb and make sure you are getting fuel flowing.
It sounds like the engine may be running ok when started when it has a full fuel bowl. If the bowl is full it runs ok, and when the fuel is lowered in the bowl it stalls. Just something to check.

Thanks for the pointers. I did find some munk in the fitting into the carb. It is possible that something got dislodged and found it's way in. I do have an inline filter that is new so shouldn't be anything from the tank. The plugs are darker but not really crusty. They have maybe an hour or so run time- not really that much. They were new about 2 months ago. Gap is right about .020". I have been careful with the drill bits and it was running very nicely recently so I dont think I've buggered anything just some munk I suspect.

Pull the the fuel tank valve and check your tank outlet hole, I've had my RD4 do that to me several times after using the tractor, the crud in the pilot tank sloshes around and always finds it's way into the outlet hole, even after pulling the tank and giving it a good clean, the next day I've had the same issue with fine rusty crud choking the outlet.

Hi Mangoman,
If every thing else looks good I would look at the governor, it might have dry bearings or the weights are sticking in it also check the shaft going into the housing it to could be stiff
When I do a pony motor up I just replace the 3 bearings and 2 gaskets.

Regards

Hi Nathan , sounds like some good pointers to try from everyone but one thing I've had happen that wasn't mentioned is the vent hole on the gas tank cap. If the vent becomes clogged it will slow or completely shut off the fuel supply. Easy way to check is to start the motor with the cap unscrewed or completely removed. If it returns to normal you just need to clean the cap vent hole. Good luck

Check to see how much flow you are getting through your in line filter, most are not advisable on a gravity system, screen type are better.

d2gary wrote:

Hi Nathan , sounds like some good pointers to try from everyone but one thing I've had happen that wasn't mentioned is the vent hole on the gas tank cap. If the vent becomes clogged it will slow or completely shut off the fuel supply. Easy way to check is to start the motor with the cap unscrewed or completely removed. If it returns to normal you just need to clean the cap vent hole. Good luck

I had just posted my "pony gas discovery" before reading these posts!!!