Reply To: JW 14 compression numbers?

[Don]

David Stanton wrote:

JWs are known for a headgasket leak between the two cylinders and this makes for the low compression readings that are the same on both cylinders. Usually it’s more like 35 pounds and it won’t start, but you may have early stages of a headgasket leak. When this happens, the head is usually warped a bit and needs to be rubbed on emery paper on a hard flat surface to flatten the head. If the headgasket is bad, you will see the problem in the gasket when you remove the head.

I’m assuming your compression gauge has it’s checkvalve at the spark plug hole and not on the gauge at the end of a rubber hose. If it’s on the gauge end of a hose, you add the volume of the hose to the compression factor, and on these little cylinders, I’d expect a reading of 60 pounds or less. There have been message strings here in the past about this problem, and I’ve experienced it with a gauge I no longer use on really small cylinders.
Dave

You are correct of course…I based my responses on my assumption that he had the head off already…. Maybe not…