Spark plugs for H or M

HenryO · May 17, 2014

What is the best plug for these tractors? Autolite or Champion or Bosch. Also what number plug(heat range) do you recommend. Thanks Henry

DeltaRed · May 17, 2014

I use whatever the parts man hands me.I havent nad any problems with any of them.Use the (standard) heat rang recomended in the book.

PretendFarmer · May 17, 2014

I had auto lite 386's in my H. They kept loading up. It ran what seemed good but then I put auto lite 3116 plugs in and it runs way smoother. The steering wheel used to vibrate before but not now. 3116's are hot non resistor plugs and I wouldn't put anything else in ever again.

randy hall · May 17, 2014

autolite 3116

IAtractorKid · May 17, 2014

Depends if it has a mag or distributor ignition. If mag you want a non resistor plug such as Autolite 3116. If distributor, Autolite 386.

FBH44 · May 18, 2014

I had Autolite send me a spark plug catalog a while back. Here's what they say about how 'hot' their various plugs are;

2014 Autolite Spark Plug catalog
Heat Range Chart page 4-5

18MM thread size
1/2” reach
7/8” hex
HOT rating
 388 Standard resistor plug
 3116 ‘Power-Tip’ Non-Resistor plug
 386 Standard resistor plug
 -- gap --
 -- gap --
 373 Standard Non-Resistor plug
COLD rating

Each step up = 70º – 120º increase in spark plug tip temperature.

Self-cleaning zone = 500°C to 850°C tip temperature.

TOO HOT = Possible severe engine damage, pre-ignition, detonation with racing
/ high performance engines. .
TOO COLD = Possible fouling, possible mis-firing, but no engine damage.

Spark plugs for H or M

HenryO

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DeltaRed

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PretendFarmer

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randy hall

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IAtractorKid

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FBH44

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