intermittent stalling/dying

[Phil960]

1955 960 NF 172 6 volt.

Started the tractor this morning, let it warm up, then proceeded to plow the snow off the drive and lot. After a couple of passes it shut off as though I had turned the key off. Started right back up and after a couple more passes, same thing. After a couple mores passes, it died and would not start. Waited a few minutes, still would not start. Turned the key off then back on and it started but ran sluggish then died. Started up again and ran fine. Finished moving snow and put it back in the shop. The shop is heated. Ran some errands, got back and started it up, let it idle then moved the throttle up to about 1500rpm and it started missing a beat every now and again and then died as though I had turned the key off again.

I'm thinking possibly a fuel flow problem. The sediment bowl never ran out of gas so maybe the screen in the bowl has some gunk in it? Or could this be and electrical issue? And the way it just died instantly doesn't seem point to a fuel problem does it?

I know I need to do more searching to pin point the problem but I'm hoping that you guys with much more experience with these tractors might have seen this before or can help me head in the right direction.

Thanks in advance for any help. Phil
 

[old]

I would start by hot wiring it. As in run a wire from the ignition side of the battery to the coil and start it up. If it runs fine then the problem is from the coil back to the battery and a bad switch can do what your saying it is doing. If that does not work check spark and make sure it is a good blue/white and jumps a 1/4 inch gap the moment it dies. If that is ok them pull the carb drain plug and let the gas flow for a few minutes. Catch it so as to check for dirt water etc.
 

[Phil960]

Thanks old, I will take those steps in order and report back what I find.
 

[KrisNMo]

When I first got my NAA I was having the same type of problem, found it to be the key switch itself. Not saying that's your problem but that's where I would start first.
 

[souNdguy]

ditto what old said on hotwireing the coil.

that 100% tells you it's not a key or wireing problem TO the coil.

I'm thinking fuel flow.

what's a drain from the bottom of the carb look like?

post back
 

[1955800]

Just the other day I had similar symptons and figured coil, under load once things got hot. I figured coil breaking down but checked points then tossed in a good used condenser since I had things opened up. No help so I made a NAPA run and picked up a new coil, needed a spare anyway. Still no help. Fuel looked clean so I pulled the fuel line, flow was too slow so I back blew the line and flow increased. Some fine junk in there, fixed the problem. Had to blow it once again but at least I know the problem. Check your fuel flow.
 

[GT65]

I had similar trouble upon start-up when cold.Had to tap the side of carb, floats were sticking!
Gt65