compression problem

[Mac from NS]

Well today I lost compression in #2 and #3 cylinders. I’m guessing a head gasket. Any thoughts? Thank you in advance.

[Bigdog]

Sounds reasonable.

[Mac from NS]

Thanks for the reply Bigdog. Have you replaced one lately, just thinking about the cost?

[Bigdog]

I bought a stack of them from Weber's Tractor Supply (NOSIH). I got a good deal on on them that way. I'd guess you should be able to get one for $15 - $25 at a dealer. Call Ken at Carter & Gruenewald.

[Mac from NS]

Thanks, I thought maybe more than that. I guess i'm going to change
the front seal too. I been waiting for the right time and this is it.
Have a good one.

[Clark Thompson]

I doubt that the head gasket went bad. I often find that a cub engine that looses compression suddenly is a result of alot of carbon build up on the cylinder head and piston. It comes loose and gets lodged in the valve seats causing a low compression. I would sudjest taking the head off and doing a valve job. You will have to replace the head gasket too..

[Russell F]

I kinda suspect the valves also, even if it is the head gasket it wouldn't hurt to give the valves a once over and maybe lap em while you are there.

['Country' Elliott]

Hey MAC...If I were you...BEFORE I removed the cylinder head...I'd try adding a couple of ounces of SEAFOAM straight into the affected pistons...let it sit overnight and then start her up!

Seafoam dissolves carbon deposits and it may help you, prior to having to do a valve job

[Joey]

Country:

I've seen a few posts about using Seafoam and how good it is. Exactly how do you use that stuff? Mix it with the gas? Squirt it in the spark plug hole

[Rudi]

Mac:

Give Jan Van Oostrom a call.. He is a really good IH dealer and is a Cub-a-holic himself and one of the participants at CubFest Northeast 2004. He supplied all the parts needed for the Governor rebuild workshop. Jan is pretty good to deal with and I can tell ya, the head gasket is not that expensive.. I got one for Ellie last fall.

Jan has a couple nice Cubs that were restored.. including a white demonstrator...

[Mac from NS]

What is the chance that carbon is going to get under the valve on two differant cylinders at the same time.Maybe i'm missing something here. I think i'm going to put the air to the cylinder and see where it's going. It's the cheapest way to start,but I will try the seafoam before the head coming off. thanks everyone

[beaconlight]

Good man Mac. I always have to remind my self KISS Keep it simple stupid. I don't always remember but when I do it helps. At my age senior moments come oftener than I want them too. Then again in Kindergarten I was voted least" likely to remember". With that in mind I always claim I will never get alheismers. I never could remember anyway.

Bill

[Eugene]

About the only common thing that would cause simultaneous compression loss in two adjacent cylinders would be the head gasket. You could have cracked the head, lost cam lobes, knocked holes in pistons - whole bunch of stuff. That's unusual let alone two adjacent cylinders

You could pull the valve cover and see if the valves are functioning properly. I would believe they are.

I assume you did a compression test.

Might as well. Minor overhaul.

Eugene

['Country' Elliott]

Hey Joey...SEAFOAM was developed by engineers for use in marine engines to remove carbon deposits and help clean valves in engines using oil and gas mixtures. Many of us on the board have had a lot of success using SEAFOAM in tractor engines, lawn mower engines, etc.

You can mix it in with the gasoline...you can use it straight into the top of cylinders...clean and soak carburetors in it...you can spray it on valves...valve springs and guides. Anywhere that carbon can come into contact with internal engine parts...SEAFOAM REALLY WORKS.

I've used it in ALL my gas engines for years with GREAT results

[wrt]

I too am having compression issues, was running when i backed in the garage after plowing snow, hasn't run since. I checked compression, had about 25 - 30 lbs/cylinder, poured gas right in the holes, wouldn't fire. Pulled off head and found carbon that had been building since the valve job in 1973. Cleaned everything up and re-assembled with a new head gasket ($24) and will not fire except some minor popping through the carb. Average compression 80 lbs. I talked to the local IH mechanic who has rebuilt many cubs and told him the story which includes the fact that I didn't lap the valves - dumb move. He said he learned the lesson after regrinding and re-assembly the tractor would not start. He pulled the head back off and lapped the valves tractor ran. Does this make sense to you guys? I noticed when I took the valves out the springs are not very strong, I can compress them easily with my fingers. Is this a sign that I should replace them as well or are they just not very strong to begin with?