1968 yachtwin cylinder pressure

[piperjomo]

Can anyone tell me what the cylinder pressure should be for a 1968 evinrude yachtwin 3hp twin cylinder.
I checked it and i'm getting 4bar about 58psi on each cylinder which seems a bit low
thanks

 

[lindy46]

Re: 1968 yachtwin cylinder pressure

The readings are even both cylinders, so that's good. 58PSI is a little low, but not unreasonable. I'd set the motor with cylinders pointing up and pour a little Seafoam in. Let it set at least overnight and see if compression improves. If the motor hasn't been run in a while, you may have some sticky rings.

 

[JB]

Re: 1968 yachtwin cylinder pressure

You are getting typical readings from a healthy rope start engine, piperjomo.

The purpose of compression testing is to discover any differences in cylinder compression. It is very rare (headgasket blown between cylinders) to have faulty cylinders both go "bad" by the same amount at the same time.

 

[piperjomo]

Re: 1968 yachtwin cylinder pressure

Many thanks for the replies.