Farmall H carbon fouling plugs

[KSmark]

I have a 1941 H had it about 4 years.I live in the city so no land sits in garage.First couple of years went to 3 tractor shows 1 tractor drive .I Start once a month at least, let it run 15 to 20 minutes.Dont start during the winter.It has always started well.But the last 4 or 5 months it is carbon fouling all the plugs.I usually have to clean after 1 15 minutes of running.Which is just sitting in front of garage on medium throttle.I do have the hotter plugs in it .Right now i cant think of brand.But they were suggested on this form.Carburetor got rebuilt when i bought it has not been readjusted.Researching problem seems maybe it just needs a long drive? But the last 2 years no driving at all.It started fine till 4 are 5 months ago.Not really much of a mechanic myself.But can do a little.So thoughts on first place to start.Thank you

 

[rustred]

you will never have clean burning plugs just by starting a tractor every so often. its when the engine is up to operating temperature and pulling a load is when the plugs will be clean if the engine is in good shape. they should have a brown tinge to them .plug brand has nothing to do with it.

 

[caterpillar guy]

You need to either be able to borrow a plow at a plow days or buy one to use at them and wrok the bag off it every summer for several plow days. Don't be afraid you will hurt it working it. That was what it was made for. Let it work hard plowing and your problem will clear up. It will foul plugs left and right setting running at half throttle just a few time a year. It needs to come in with it's tail dragging from work.

 

[Brownie450]

I'd try turning the main jet in an eighth of a
turn to lean the mixture a bit.
Jim

 

[Janicholson]

As noted below. Farm tractors have cooling systems that can remove engine heat in the summer while the engine is running wide open pulling tillage or harvesting attachments. The thermostat bypass is large enough to never even get the engine to working temps idling at 1/2 throttle. Ask local farmers to allow you to disk up a 20 acre field. that is what it needs. Jim

 

[redforlife]

I'm not so sure that you'd have to put it to a hard days plowing to avoid the carbon problem. But definitely put it in a situation where you open the throttle all the way up, and blow the cobs out of it from time to time. A little drive in 5th gear up a street with a reasonable hill or incline will warm her up a little, and blow the cobs out.

My H's don't see any heavy draw bar work anymore. A hay rake is about as hard of work as they see (and that's pretty light duty work). I don't have any spark plug issues.

Make sure your carb is not set just a tad rich. Throttle should be responsive when you open it up quickly, and no black smoke coming out of the exhaust.
If carb was set by the book, and just left at that, it might need a hair of fine tuning.

 

[K-Mo]

Had same problem with my H. Autolite 3116 plugs helped some. Gave it a good dose of Seafoam. Runs good now. I assume sticky valves.

 

[560Dennis]

They were designed to be worked hard .
Here a list to plugs they might help if all is well with motor and fuel system adjust. I use vacuum gage to tell.