8N quits when hot

1950 - Starts first crank every time. Runs like a top. Gets hot, stops running after 30-45 min (depending on load). Restarts when cooled down.

Replaced coil and condenser - no change. It's 12V - I didn't do the change, it's been solid the 2 seasons I've owned it.

Reading old posts, looks electrical - not sure what's next. Looks like other culprits could be
Ignition switch (replaced last year - low probability, but it is a cheapo switch)
Thermostat
Gas tank cap/vent (can check this next run)
Water pump (will peek in on flow next run)
Anything else I should be looking at? Hate to shoot the parts cannon at it, but most everything could stand to be replaced anyway. . .

Thanks!
Slow

(quoted from post at 08:16:02 04/20/21) 1950 - Starts first crank every time. Runs like a top. Gets hot, stops running after 30-45 min (depending on load). Restarts when cooled down.

Replaced coil and condenser - no change. It's 12V - I didn't do the change, it's been solid the 2 seasons I've owned it.

Reading old posts, looks electrical - not sure what's next. Looks like other culprits could be
Ignition switch (replaced last year - low probability, but it is a cheapo switch)
Thermostat
Gas tank cap/vent (can check this next run)
Water pump (will peek in on flow next run)
Anything else I should be looking at? Hate to shoot the parts cannon at it, but most everything could stand to be replaced anyway. . .

Thanks!
Slow

Click to expand...

oes it have spark when it quits?

Does it have fuel flow out bottom of the carb when it quits?

RogerinIowa / R Geiger

Always quits way out from tools - will load up next time I run it and check for spark and fuel flow. - thanks!

I can't imagine having a tractor without at least a crescent wrench, pliers, screwdriver, and a can of wd in a toolbox.... maybe you should consider adding the above...

Front or side distributor? Troubleshooting is different.


These tractors are pretty simple machines; its usually pretty easy to get them running with some basic troubleshooting steps. You can:

1. Replace every part you can until it starts or you run out of money.

2. List every possible cause of the problem and then randomly pick your favorite to check. It could be your coil. Or your ignition switch. Or about 10 other things.


3. Like diagnosing any other equipment failure, take a step-by-step approach, working from the most likely to the least likely, one system at a time.



Ive tried all three approaches. The third one always worked for me.



I might not be able to tell you why your tractor isnt running, but I can tell you how to figure it out for yourself.


You could have a spark issue.


You could have a fuel issue.


Dont guess. Troubleshoot. See tip # 13 at the link below.


as soon as it stops, not 5 minutes later, you need to answer 2 questions before you do anything else:


With the bolt in the carb bowl removed and the gas on, will the fuel flow fill a pint jar in less than 2 minutes?


Next, get out your adjustable gap spark checker * , open the gap to 1/4, hook it up, turn the key on and crank the engine. Does the spark jump 1/4? Post back with the answers.


And do not buy a new part for the tractor until you can answer this question: how do I know the part on the tractor is defective?

Once you narrow the problem to spark or fuel, post back and tell us what you found (and how you found it) and you will get plenty of help to get your tractor running.



* Don't own an adjustable gap spark checker? Buy one! Not a test light! Until then, take an old plug, open the gap 1/4 ground it to the head & look for spark. Its not the color of the spark that counts; its the distance it jumps.

https://www.autozone.com/test-scan-and-specialty-tools/ignition-tester/oemtools-adjustable-ignition-spark-tester/10257_0_0?cmpid=PLA:US:EN:AD:NL:1000000:TLS:71700000043798748&gclid=Cj0KCQiAovfvBRCRARIsADEmbRKBdAvAmtFfOvYiYXR7T6NYiW57uyv5-dEKjVT_h2KogQNUUMsRixYaAlU3EALw_wcB&gclsrc=aw.ds
75 Tips

You can fit enough tools inside that little toolbox to fix or diagnose most N problems...........

A jumper wire , with alligator clips, is handy to jump across the resistor block. That will give you bat voltage to the wire that feeds the coil. Don't leave that connection in place long except to try to start it, it could hurt the coil/points.

The jumper would rule out faulty key switch or resistor.

Could be a bad coil. When coil heats up, it has a short. When coil cools down, short goes away.
Just a guess.

(quoted from post at 07:16:02 04/20/21) 1950 - Starts first crank every time. Runs like a top. Gets hot, stops running after 30-45 min (depending on load). Restarts when cooled down.

Click to expand...

Check your fuel flow like Bruce says, as it sounds like your fuel flow is restricted. Heavier load uses more fuel and it stalls sooner. Less load (or lower RPM's) uses less fuel and it runs longer, as fuel is able to replenish itself in the bowl.

Friend of mine had the same problem. Turned out to be dead insects stuck in the intake of the on/off/sediment bowl valve right at the bottom of the gas tank.