Flat head 4 cylinder not firing on 2 and #3 cylinders HELP

Copperhead don't play · Nov 7, 2019

New plugs, firing on each plug, 120 compression on all 4 cylinders, BUT number 2 and 3 are not working. If I ground out number 1 and 4 plugs, it stalls the engine, if I short out the plugs on number 2 and 3 there is no change in RPMs. Needing advice.

By the way Cub Cadet184 4 cylinder flat head.

Thanks,
Copperhead

cole in mo. · Nov 7, 2019

Are you sure the wires are on the right plugs, and the wires in the right rotation in the cap?

MikeJM · Nov 7, 2019

Did it do this before new plugs? Did you check and make sure 2 and 3 plug wires are in the right place? Firing order can be 1-2-4-3 or 1-3-4-2 depending on the engine. I don t remember what they were.

used red MN · Nov 7, 2019

Also a symptom of a leaking intake manifold or head ..er block.. to manifold gasket in this case.
Start it and hold an unlit propane torch tip around the gasket and manifold area to see if the rpm
change. If it does you likely found your issue. Either or carb cleaner will also work.

Steve@Advance · Nov 7, 2019

Check the intake gasket for a vacuum leak.

That type manifold will "sometimes" burn through, let exhaust gas into the intake, an internal vacuum leak.

Save that for last though, no easy way to test it short of removing the manifold.

As said, triple check your firing order, check the point gap, valve lash, valve springs.

old · Nov 7, 2019

I would have said head gasket but you have compression on all the cylinders. So maybe a bad intake manifold or maybe a clogged intake. It could also be the manifold gasket. Spray some carb cleaner around the gasket area of a propane torch unlit around the gasket area and if it fires then you know you have a manifold problem

BarnyardEngineering · Nov 7, 2019

BTDT. You've got the plug wires for 2 and 3 swapped around.

I would have bet my life that I put the wires back on correctly that time, especially since I never had more than one wire off at any given moment. I checked, double-checked, and triple checked. Nope, they were backwards...

BTW the firing order is cast into the block: 1-3-4-2.

timcasbolt · Nov 7, 2019

(quoted from post at 18:23:55 11/07/19) New plugs, firing on each plug, 120 compression on all 4 cylinders, BUT number 2 and 3 are not working. If I ground out number 1 and 4 plugs, it stalls the engine, if I short out the plugs on number 2 and 3 there is no change in RPMs. Needing advice.

By the way Cub Cadet184 4 cylinder flat head.

Thanks,
Copperhead

I highly doubt we're talking about a Cub Cadet. Also, I highly doubt we're talking about a flat head engine.

BarnyardEngineering · Nov 7, 2019

(quoted from post at 11:55:08 11/07/19)

(quoted from post at 18:23:55 11/07/19) New plugs, firing on each plug, 120 compression on all 4 cylinders, BUT number 2 and 3 are not working. If I ground out number 1 and 4 plugs, it stalls the engine, if I short out the plugs on number 2 and 3 there is no change in RPMs. Needing advice.

By the way Cub Cadet184 4 cylinder flat head.

Thanks,
Copperhead

Click to expand...

I highly doubt we're talking about a Cub Cadet. Also, I highly doubt we're talking about a flat head engine.

An International 184 LoBoy is commonly, though mistakenly referrred to as a "Cub" or "Cub Cadet." It is based off the International 185 LoBoy, which in turn was based off the International 154 LoBoy, both of which were painted like Cub Cadets and shared styling with Cub Cadets, so it is understandable.

All were based off the original Farmall Cub, and have a 4-cylinder C-60 FLATHEAD engine just like the original Cub.

rustred · Nov 7, 2019

all you did is put the firing order in the wrong rotation. and that is exactly what will happen. cyl. 2 and 3 will not fire.

rustred · Nov 7, 2019

what makes you thing that? I have the 154 and yes it is a 4 cyl. flathead engine.

john *.?-!.* cub owner · Nov 7, 2019

(quoted from post at 19:45:57 11/07/19) what makes you thing that? I have the 154 and yes it is a 4 cyl. flathead engine.

54,184,185, or Cubs, not Cub Cadet. That is a common thing to hear, no big deal, still 4 cylinder flat head with firing order of 1,3,4,2.

john *.?-!.* cub owner · Nov 7, 2019

Most likely 2 & 3 plug wires are swapped. 1 & 2, and 3 & 4 are two separate manifold gaskets, so that is ruled out.

Copperhead don't play · Nov 8, 2019

MANY Thanks for the advice. It is now running perfect. Like you said the #2 and #3 plug wires were swapped.
Thanks for the advice; it is a Cub LoBoy 184 four cylinder flat head. I misspoke saying it was a Cub Cadet.

old · Nov 8, 2019

Funny how an engine will not run right with out the firing order being correct and that is an easy one to mix up

john *.?-!.* cub owner · Nov 8, 2019

I showed up early at my cousin Bob's estate sale in case they needed some help with something.Auctioneer asked me if I could take a look at Bob's Farmall Cub. He said several people had been by looking at it during the week, and when they went to bring it out of shed it would not start, only spit a little. When he said that I checked spark plug wires. Sure enough, they had been swapped around.

Flat head 4 cylinder not firing on 2 and #3 cylinders HELP

Copperhead don't play

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