Ford 601 starts, runs rough, then dies

Ford 601. Has been running great for months but the other day it died and won't restart.

It turns over, fires, runs rough for a while, then eventually dies. Playing with the throttle and / or choke lets it run a little longer.

Within the past year or so, the tractor has had a new distributor, new head gasket, valve job, converted to 12 v, new zenith carb, and added in line fuel filter.

Had used just a day or two before but this time after running a few minutes - maybe 10 to 15 - it died and I have not been able to get it restarted as noted above.

I thought maybe it might be not enough gas or a vacuum with gas cap. Added more gas and loosened the cap. Same result.

I replaced the in line fuel filter with a new one. Same result.

I put the previous Marvel carb back on. It started and ran slightly longer but still died.

The Zenith carb appears to flood. The Marvel doesn't. I took zenith carb apart and checked / cleaned fuel float valve. No change. I am not sure if the problem is flooding or fuel starvation. There is visible gas in the in line fuel filter and it runs out the back of the zenith carb so it does not seem to be fuel starved but rather flooded . May partly have been me choking over and over though. the Marvel carb is not flooding. I suppose it could be bad too and is blocking fuel.

I would appreciate suggestions on what to do next:

- could it be the coil? I have read that can cause a problem like this but it is usually 15 min or so after it warms up
- should i rebuild or replace the carb?
- could it be blockage from the fuel shut off?

Anyone have any other ideas.

I replaced the in line fuel filter with a new one. Same result.

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That tractor did not have an in-line fuel filter when it left the factory. Try removing that filter and run the fuel line directly to the carburetor.

I'm a little confused. You say that the tractor died and you couldn't get it restarted. Later you say that you switched carbs and it restarted.

Your problem could be electrical, fuel, timing, compression or ???

Have you checked to see if you have spark? If you don't have good spark, the problem could be points, condenser, coil, wiring just about anywhere, or ???.

If you changed the distributor, are you sure that everything was tightened properly? If not, the point setting may have moved, the distributor may have moved (changing the timing), you might have a bad electrical connection, etc. I once had a problem with my Ford 600. I was sure that I had a problem with a bad coil, so decided to replace it. When I tried to disconnect the wire to the coil, the wire broke in my hands. It turned out that the braided wire was frayed inside the insulation.

You don't seem to know whether the engine is flooded or fuel starved. Have you checked to see if the plugs are wet, oil fouled, or covered with carbon? This might provide a clue.

There are lots of possiblilites

Thanks for your comments and suggestions. I will certainly give them a try. It is all the possibilities of problems that is a challenge for me.

Let me clarify a couple things.

The changes I identified as having been made (distributor, new carb, new head gasket, valve job, etc) were all made months ago and the tractor has been running well for months.

It is just recently that it died. I had used it the day before and for some time that day before it died.

It fires, runs rough for a short time (seconds to a few minutes), and then dies. It did the same for both carbs but it ran slightly longer when I used the older Marvel carb. The Zenith carb appears to be flooding although part of that could be me choking it excessively to keep it running. The Marvel carb does not show signs of flooding (at least no gas running out the back end) but it still runs rough for a short period and dies.

Because it fires, I am obviously getting some spark. I have checked that all spark and coil wires are well seated. I have not pulled a plug yet to check for fouling or opened the distributor to check the points / condenser. I guess those will be my next steps.

I was hoping someone might recognize this as a problem they have had in the past and could quickly identify some obscure problem to resolve it.

Thanks

I had considered that and am willing to give that a try but I am curious as to why you think that is the problem. It has been running for months with the in line filter without any problem.

(quoted from post at 11:23:30 08/18/17) I had considered that and am willing to give that a try but I am curious as to why you think that is the problem. It has been running for months with the in line filter without any problem.

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Does the filter specify that it is designed for, and can can provide proper flow for, a gravity fed fuel system? Is the new one the exact same make/model as the previous one? Perhaps the original one eventually clogged up and the new one isn't the same exact type? Most in-line fuel filters at Tractor Supply are for lawn mowers and lawn & garden tractors that do not require near as much fuel flow as a full size tractor. Needing to choke it to get it to run means that it either is getting too much air or not enough fuel.

An additional though just hit me, have you checked for water in the fuel?

Take a look at the points to make sure they are working and you have good spark. A bad condenser can do that too.

MS carbs are easier to work on imho. I'd go with that one, esp since the other floods. I'd pull the dist. cap and crank it over and check for good spark at points. If it has good spark at points that eliminates condenser and coil problems. If spark is good at points, put cap back on and check spark at plugs, investigating what plugs look like as you do. Back to carb, pull plug at bottom of carb and see if fuel flows boldly out bottom of carb (into clean bucket). Like Sean, i dislike the inline filters. If fuel flows and then slows and stops or almost stops, you have a blockage between tank and carb or in carb. It should flow boldly and steady. To summarize, install carb because you don't want fuel going all over, but then check the spark condition first and then fuel flow. HTH.

Thanks. That is a good easy set of things to try before I start replacing parts. I'm going to give it a try today.

And the winner is ..... points

Thanks to everyone who pointed me in that direction. I have had many carburetor problems before and when it fired I assumed it was a fuel problem and not an ignition problem. I forgot how finicky the old ford ignitions were.

I had considered replacing points with electronic ignition. Has anyone had any experience with that?