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Low Pressure Compression Test and Leaking Oil

MLo3

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Location
Pittsburgh, Pennsylvania
Boat Make
Yamaha
Year
2005
Boat Model
AR
Boat Length
23
I took my 05 AR230 to a mechanic after I pulled it out of the water this year and asked them to look the engines over since I hadn't had it done since I bought it. They ran a compression test and reported low pressures on both engines. I had some issues with the oil in the port engine towards the end of the season, it didn't seam like it was holding. I couldn't locate a direct source of the leak so I refilled it once or twice before the season ended. My check engine light would also turn on for the port engine, usually towards the end of my days,

The mechanic said I may be looking at a rebuild, however after navigating the forums, I'm seeing this issue can be common. I'm not very mechanically inclined so I'm looking for any opinions out there on what might be wrong and what measures I would have to go to to fix these issues. The boat ran fine throughout the summer.

Thanks in advance for any suggestions/opinions.
 

Cobra Jet Steering LLC

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What were the individual compression readings and what did the spark plugs look like? Those are the report card of your engine
 

MLo3

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Reaction score
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Location
Pittsburgh, Pennsylvania
Boat Make
Yamaha
Year
2005
Boat Model
AR
Boat Length
23
What were the individual compression readings and what did the spark plugs look like? Those are the report card of your engine
110/90/90/105 port 115/97/100/90 starboard
I had them replace the spark plugs, not sure if they tested before or after. Didn't get a chance to look at the old plugs.
 

Cobra Jet Steering LLC

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Those are pretty low but all close together ,80 is the minimum you can have. The oil is probably just being consumed. You could have the engines rebuilt or just continue to use it another season maybe go to a heavier oil. As you said the engines are still running ok.
 

MLo3

Well-Known Member
Messages
34
Reaction score
7
Points
57
Location
Pittsburgh, Pennsylvania
Boat Make
Yamaha
Year
2005
Boat Model
AR
Boat Length
23
Those are pretty low but all close together ,80 is the minimum you can have. The oil is probably just being consumed. You could have the engines rebuilt or just continue to use it another season maybe go to a heavier oil. As you said the engines are still running ok.
When I pulled the drain plug, it was clear there was oil present in the water while it was draining. I'm thinking the oil isn't being consumed.
 

Cobra Jet Steering LLC

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ok check the oil filter for leaks or the valve cover gasket, the oil filters rust around the crimp area and do leak I put metal tape over them to protect them from rusting
 
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