What's wrong with my 2000

[Mike(NEOhio)]

72 three cylinder. It's always been a solid runner. Using it the last few days to mow a 9 acre field with lush grass. Several hours in 3rd at 1900
RPM and running great. Went to ted, adjusted the depth, got on to start in and it just died and would not restart. I pulled the coil wire and had
good spark, replaced it and it fired right up. Thought maybe the wire got loose. Next day I raked about an hour then went back to the field mowing.
It ran good but seemed to be laboring a bit. Nearly two hours and almost finished it started sputtering and died in some heavy grass. I pulled the
carb drain and had good flow, got it restarted and finished up. Heading back to the shed and slowed up and it would not idle, died again. Restarted
then it ran good. What should I look for, sediment bowl it clean. I'm thinking something in the carb. Holley and it's been trouble free for me but
it's a long time since I had it off to clean, 15 yrs maybe.

 

[Sean in PA]

Lots of possibilities. It might be a partially clogged fuel cap vent or the coil beginning to go bad, or a loose electrical connection, or junk in the tank floating around and only clogging the screen some of the time...

 

[DanielW]

+1 to what Sean said. When testing flow from carb, make sure to let a good amount run out. Sometimes if the crapulence in the tank is floating around it will have good flow for a while, until the
whirlpool effect brings the junk to the outlet. Don't discount the condenser either - they can do funky things when they start to go bad. Sometimes a bad condenser will still allow decent spark
but cause erratic timing. Sometimes a bad condenser only starts to misbehave when it gets warm and behaves again when they cool down. It's pretty common for a condenser to go bad (especially new
condensers). It's pretty rare for a coil to go bad.

 

[kenbob]

I think there is a screen on top of the sediment bowl. It could get plugged and unplugged with the tractor moving. THere are also tiny screens at the fuel pump on the front of the tractor. Once those plug you are usually done until you clean them. All of this applies to the 2000 3cyl. Don't know about the old 4 cyl.

 

[Steve in IL]

When it starts running rough, can you get it to recover by pulling out the choke? I have a gas 4000 of similar era with that symptom. Still working on a cause.