Farmall H firing on two cylinders question

JeffersonDeere · May 18, 2016

First off, I apologize for my offensive handle! This is my first foray into a red machine and I am learning so so much. I bought a few Farmall H's a few years back and am working on restoring the first one, a 1945 widefront H. The #2 cylinder was stuck so I pulled the head, freed it up, and had the head worked over in the local machine shop where he replaced the valves and cleaned it up. My Dad and I installed the head, torqued everything up, and put it all back together. Went to start her up and nothing. Pulled the carburetor and did a quick cleaning, and checked the points. No spark. It has a mag, so set the points to .013 and we have a super hot spark! Finally got it to start and she idles but sounds rough. Not having a whole lot of experience with Farmalls, I cant tell if its missing or not. My Dad seems to think it is. So, we started pulling spark plug wires. The #1 and #2 cylinder are DEFINITELY firing, however, we dont think that #3 and #4 are. We pulled the plugs and wires and checked everything, then turned it over while grounding the plugs out on those two cylinders. All have hot spark and look normal. What am I missing? We have played with the timing to no avail and am a bit of a loss!

kevinj54 · May 18, 2016

(quoted from post at 20:36:26 05/18/16) First off, I apologize for my offensive handle! This is my first foray into a red machine and I am learning so so much. I bought a few Farmall H's a few years back and am working on restoring the first one, a 1945 widefront H. The #2 cylinder was stuck so I pulled the head, freed it up, and had the head worked over in the local machine shop where he replaced the valves and cleaned it up. My Dad and I installed the head, torqued everything up, and put it all back together. Went to start her up and nothing. Pulled the carburetor and did a quick cleaning, and checked the points. No spark. It has a mag, so set the points to .013 and we have a super hot spark! Finally got it to start and she idles but sounds rough. Not having a whole lot of experience with Farmalls, I cant tell if its missing or not. My Dad seems to think it is. So, we started pulling spark plug wires. The #1 and #2 cylinder are DEFINITELY firing, however, we dont think that #3 and #4 are. We pulled the plugs and wires and checked everything, then turned it over while grounding the plugs out on those two cylinders. All have hot spark and look normal. What am I missing? We have played with the timing to no avail and am a bit of a loss!

Have ya checked the compression???

Charlie M · May 18, 2016

I thought 2 cylinders was OK with you guys - just kidding. Some thoughts - have you got the firing order correct - 1-3-4-2 with number one closest to the radiator. Did you have the mag off the tractor - if so could be reinstalled incorrectly. When you had the head off did you get the valves set correctly - should be at top dead center on the compression stroke I believe but could be wrong. Have you got compression on all cylinders. Do the cylinders not firing get gas - should have wet plugs when you pull them if its not firing. Could you have flooded the cylinders? Maybe if it was running at idle its a carb issue. A leak in the intake manifold will make it run rough. When it was running did giving it some choke help.

khouse6 · May 18, 2016

i do not mind them idling rough, as long as they run good when pulling, etc.

JeffersonDeere · May 18, 2016

(quoted from post at 01:46:41 05/19/16) I thought 2 cylinders was OK with you guys - just kidding. Some thoughts - have you got the firing order correct - 1-3-4-2 with number one closest to the radiator. Did you have the mag off the tractor - if so could be reinstalled incorrectly. When you had the head off did you get the valves set correctly - should be at top dead center on the compression stroke I believe but could be wrong. Have you got compression on all cylinders. Do the cylinders not firing get gas - should have wet plugs when you pull them if its not firing. Could you have flooded the cylinders? Maybe if it was running at idle its a carb issue. A leak in the intake manifold will make it run rough. When it was running did giving it some choke help.

HAHA, well done with the two cylinder comment!!! You definitely gave me some things to check into. Believe the firing order is correct, it was the first thing we checked out. As for setting the valves correctly, I may need to check into that to make sure that is set up correctly. Mag was NOT off the tractor, but Im assuming it was in the correct position as it ran fine before I bought it (with stuck cylinder, LOL). Anyhow, more to follow, thanks for the input!!!!

F-Dean · May 18, 2016

Check the rotation of the distributor (Clockwise or Counter-clockwise) If you have the wires in the right order but in the wrong direction, only 2 cylinders will fire at the correct time.

Yes, this is based on experience!

rustred · May 18, 2016

best be checking the compression, as if the valves are not closing against the seats then you will have no compression or very little, due to the lash being too tight. i believe the setting is .017 hot. set valves following firing order., you need to have #1 cyl. on tdc on compression stroke and set those valves , next get #3 cyl. on tdc on compression and set those , then do cyl 4 and 2 the same way.
and if you had the wires on backwards you would only have cyl's 1 and 4 firing.you can definitly hear the miss when one wire is removed from the cap when running. or just remove the wires from the firing cyl's and if the other 2 are not firing it will stop. that engine will run on one cyl. with 3 wires removed. and last you should know what 2 cyl's running sound like. it dont have to be a deere to hear that. properly tuned and with a muffler you will hardly hear this engine running at idle.

David G · May 19, 2016

I would also recommend checking firing order, and doing compression test. You will either have a blow head gasket or valves not adjusted right if two adjacent cylinders have low compression.

gene bender · May 19, 2016

You have the mag installed 180 out and check the wires are correct they will run with mag 180 out easy to do as the mag drive seats in the slot of the drive gear.

teddy52food · May 20, 2016

Won't run if 180 degrees off as it will be firing between ex & in. But you can switch wires & make it right.

tractorguy2 · May 20, 2016

Odds are the valves are too tight.

gene bender · May 20, 2016

oh yes they will did it one time

Farmall H firing on two cylinders question

JeffersonDeere

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kevinj54

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Charlie M

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khouse6

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JeffersonDeere

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F-Dean

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rustred

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David G

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gene bender

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teddy52food

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tractorguy2

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gene bender

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