1976 glastron crestflight 184v-8 vacuum pressure

Losmon · Aug 3, 2015

Our boat ran beautifully until I had a boat repair shop rebuild the Volvo Penta outdrive. The boat shop doesn't take any responsibility of the current issue in having The motor had difficulty starting and when running after 10 minutes oil pushed out of the dipstick and breather. This early model is a 351 Cleveland with all factory components. Air filter with a breather cap to the right side valve cover . Left valve cover pcv valve to a hose running to the back of the Holley carb. I cleaned the breather cap ,changed the pcv and checked for any issues with the two hoses. Nothing wrong . However when I start the boat remove the pcv hose there is extreme vacuum pull from the hose. I believe this is causing lower crankcase pressure which is forcing the oil out of the dipstick and causing difficult starting. I am trying to solve this issue. Any test or obvious procedure I can do to determine the problem? Thanks boaters

Bt Doctur · Aug 3, 2015

If its connected to the rear of the carb, on a vac port you will feel vac on the hose. its there to draw the blowby vapor out of the crankcase into the engine to be burned.

Losmon · Aug 4, 2015

I understand how the system works, however , my question is what can be causing lower crank case pressure besides ring failer. I'm hoping some body has experienced this. Something must be blocking a vacuum port. The motor was compression tested when the our drive was rebuilt. I'm thinking something in the exhaust could be blocked? Really unsure, that's why I'm asking. Thanks