1978 evinrude 6hp 6804B

[Peterpd99]

The motor runs and starts easily, idles ok. Just noticed on the carburetor, there's a hole. Isn't there supposed to be a lead shot plug in there.
One more issue, I just did a compression test. Top cylinder 50psi and bottom is 90. I can hear a hiss/breathing noise while slowly turning the flywheel. My initial thought would be leaky upper crankshaft seal? Or should I start by replacing the head gasket first to see if compression improves?
Thanks in advance!
-Peter

 

[boobie]

Pull the head first. as you may have more problems than just a head gasket.

 

[racerone]

Sorry----The upper crankshaft seal has nothing to do with compression in the cylinder !

 

[Peterpd99]

Thanks racerone
I will do that.

About that hole on the carb, I don't see that on my other motors.

 

[racerone]

The carburetor bowl needs a vent hole so that there is atmospheric pressure on top of the fuel.-----That is part of how carburetors work.----Be careful if you decide that everything must be plugged !!

 

[Peterpd99]

Ok I won't touch that. Thanks for the clarifications.
I will update on the head gasket.

 

[hardwater fisherman]

Both of my earlier 6 hp motors have that hole open.

 

[Peterpd99]

I have five 6hp ranging from 1961-78, never seen that before. Learned something new.