Compression ratio for 1964 3HP Lightwin

[Flipperboat]

I had problems getting my 3 HP started so I checked the compression and did not like what I found. Does anyone know what the compression of my motor should be?

 

[F_R]

Re: Compression ratio for 1964 3HP Lightwin

Oh, somewhere around 80psi. But you must use the correct kind of gauge. The check valve must be where the spark gap would be on a plug. Gauges with a hose, and the check valve at the gauge end of the hose will give low readings.

 

[HighTrim]

Re: Compression ratio for 1964 3HP Lightwin

What did you get? As Frank stated, you are by no means going to be getting 100 psi on those little guys. Were they equal between cylinders?

 

[JB]

Re: Compression ratio for 1964 3HP Lightwin

What you will get depends on your technique and your gauge. If both cylinders are above about 60psi and within 10% of each other you are okay.

You would have saved yourself and us some time if you had told us what you got.