Spark plug issue on farmall H, is it the plug of the wire?

Anonymous-0 · Feb 23, 2014

I have an issues with a rough running engine on my farmall H, I've traced down to a poor spark issue on one of the plugs. When the plug wire is connected properly it gets hardly any spark and the engine runs rough. I pull the wire off and let hang lose , about 1/4 inch a way there is nice clear spark and the engine runs great. I put back on and runs rough.

I've cleaned the connection on both the plug and wire to ensure they are contacting. Kinda stumped for know, what's the quick solution?

Bob M · Feb 23, 2014

Problem is the plug partially fouled.

Thoroughly clean and regap plug, or better yet replace it with new and the problem will disappear.

Bob · Feb 23, 2014

You have re-discovered the "spark intensifier", which Meissner figured out in 1918!!!!
zzzzzzzzzAP

Anonymous-0 · Feb 23, 2014

Thanks, I was having a hunch that is what was going on. Now my second questions, what is the correct modern spark plug for this tractor.
I read somewhere an Autolight 388?

Will a napa auto parts carry these?

FBH44 · Feb 24, 2014

That"s what I understand, the Autolite 388 is the hottest. I believe Autolite numbers their plugs upwards in "hotness". I think the longer the center ceramic part of the electrode, the hotter it runs. I run 388"s in my "H".

mkirsch · Feb 24, 2014

There's more than one plug, but the "hot" one is about the best for "puttering around" to prevent the plugs from fouling.

You'd want a cooler plug if you were working the tractor.

rustyfarmall · Feb 24, 2014

(quoted from post at 22:31:27 02/23/14) Thanks, I was having a hunch that is what was going on. Now my second questions, what is the correct modern spark plug for this tractor.
I read somewhere an Autolight 388?

Will a napa auto parts carry these?

If your H has a magneto ignition, you want the Autolite 3116. The 3116 is a non-resistor plug and works much better with a magneto. If you have a battery ignition distributer, the either the Autolite 386 (cooler), or the 388.

John T · Feb 24, 2014

My best guess (if pulling wire off a bit helps) is the plug is starting to foul. Id run a hotter plug, the 388 is a tad hotter then the original 386 but for a tractor that shows its age and/or its used for light duty Id run the hotter 388. HOWEVER and especially if its a Magneto Ignition, Id use the NON Resistor 3116 Autolite Plug.

John T

Spark plug issue on farmall H, is it the plug of the wire?

Anonymous-0

Well-known Member

Bob M

Well-known Member

Bob

Well-known Member

Anonymous-0

Well-known Member

FBH44

Well-known Member

mkirsch

Well-known Member

rustyfarmall

Well-known Member

John T

Well-known Member

Similar threads