8N misses after running a while

[SteveinKY]

It's hot out, over 90. I'm bush hogging with the 47 8N 'cause my dang Case threw a fan blade right through the radiator. It will run OK for about 15-20 minutes then it starts missing. So I shut it off and go to the parts store and get new H-10 champ plugs and start it up and it runs good for 15-20 mintues then starts missing. I eat lunch and start it up and it runs good for 15-20 minutes then misses.

It has: new dist cap & rotor, plug wires, coil points, condenser, rebuilt carb, plugs and fresh clean gas. I'm wondering about the timing? How do I set it? Any help is appreciated.

Thanks
Steve

 

[Anonymous-0]

Classic Ignition Switch Problem---replace it--about $12.

Tim

 

[Dan]

Before running out and buying a new ignition switch - test it by shorting between the two leads.

Dan

 

[Bruce (VA)]

As a good rule of thumb, a 1 - 2 minute run times is usually the condenser, ballast resistor, or vacuum lock....or, failure to turn the gas on. A 5 minute run time is usually fuel screens. A 15 minute run time is usually the ignition switch. A one hour run time & then restarts after it cools down is usually the coil.

There are a number of reasons why it will run rough after 15 -20 minutes & timing on a frontmount is not one of them. The ignition switch heating up & acting like a resistor is on the top of the list. You can jump it like Dan sez, or just buy a new one. Seems like the rest of the ignition circuit is new, so why not?!
50 Tips

 

[mgocom]

The last one I worked on that did that turned out to be the coil. I tried everything I could think of before I talked to an OLD time Ford man. HTH

 

[Colin King]

Hi Steve,

The others gave you good advice re the switch. You might also get a set of Auto Lite AL437 plugs, which are preferred over the Champion H10s. Gap them to 0.025

Out of curiosity, how did you replace the points? Did you leave the distributor on the tractor, or take it off? It's really slick to remove the 2 bolts holding the distributor on the engine and change the points on your workbench, and saves on skinned nuckles. This way you can also set the timing for your new points - also very easy.

If you have the IT FO-4 manual, there are good instructions for this procedure.

Below is a link that also describes the process - but get the manual!!!

Colin, MN
Timing a Front Mount Distributor

 

[SteveinKY]

I took a jumper wire with me and bush hogged for about 20 minutes until it started missing. I jumped the switch and it kept on missing. The switch looks like crap but I guess I need yet another coil. Does anyone make a good one? This is the 3rd coil this year. On the previous "new" coil the wire terminal busted off. These were both TSC made-in-India-specials. What a waste of money. I can't wait long, I got to get ready for fall planting.

Thanks
Steve