Excessive oil in the spark arrestor and carburetor

[Weirthit]

During our July 4th boating my 1988 5.7 Liter Alpha One Mercruiser started hesitating when going from idle to say half throttle to get on plane. Once on plane the boat ran fine. Once back to idle the boat ran rough. I figured this was a fuel problem and decided to rebuild the Edelbrock 1410 carburetor. When I removed the K&N spark arrestor I was alarmed to see oil contamination inside and small puddles of oil all around the carburetor. Pretty sure this came from the vent hoses going from the valve covers to the spark arrestor but seems excessive.

What would cause excessive oil showing up inside of the spark arrestor?

 

[alldodge]

During our July 4th boating my 1988 5.7 Liter Alpha One Mercruiser started hesitating when going from idle to say half throttle to get on plane. Once on plane the boat ran fine. Once back to idle the boat ran rough. I figured this was a fuel problem and decided to rebuild the Edelbrock 1410 carburetor. When I removed the K&N spark arrestor I was alarmed to see oil contamination inside and small puddles of oil all around the carburetor. Pretty sure this came from the vent hoses going from the valve covers to the spark arrestor but seems excessive.

What would cause excessive oil showing up inside of the spark arrestor?[/QUOTE]

Excessive oil coming from the valve cover tubes is blow by. Sounds like you have piston ring problems. Suggest doing a compression test. How many hours are on the engine, and when was the last time the oil was changed? Also what weight and type of oil are you using?

 

[Weirthit]

The boat engine has 200 hours on it since I bought it around 2000 and installed an hour meter. The previous owner said the engine was replaced before I bought the boat but no paper work proving this.

I change all fluids every two years using 10W-40 and just changed the last month.

I will get a compression checking device and check the pressures. What are the optimum pressures on the cylinders?