Burning oil

[4wahoo]

I have a pair of 2007 175's that have been great. My last trip one started burning a LOT of oil. I shut it down and limped in. I drained and strained the oil and took apart the oil filter to see if there was any metal and didn't find any. After replacing the oil and filter I did a compression test. The top three cylinders read 160 PSI but the bottom is 30 psi. Any ideas of whats wrong?

Thanks,

Ben Smith

[artdf175]

Ring has gone bad
Valve seal or brunt valve
Unfortunately it is going to be an expensive fix!

[ChrigelKarrer]

As Art wrote,
low compression on a cylinder are either
a) leaking piston ring(s)
b) leaking valves
c) is a expensive fix
If you are lucky it's a valve and only the cylinder head has to be removed,
if there is a problem with the piston, then the power head has to be disassembled to remove the piston.

Have it checked and then valutate if the engine is worth a several thousand dollar repair of if you better get a new/used engine(s)

Chris

[redlowrey]

If you are capable remove the cam cover, turn the engine over and get the bottom cylinder on tdc on the compression stroke and make up an air fitting to screw into the spark plug hole. Put around five psi into the cylinder and listen to see where the air is escaping eg, prop throttle body and take the dipstick out and listen there. It sounds like you have done a piston, if that is the case if you run the engine on muffs it will have a miss on that cyl and if you remove the dipstick or the oil filler cap it will have smoke and cylinder pressure coming out.

[4wahoo]

Not what I wanted to hear...but what I expected. Thanks for the help. At least I'm less likely to be taken advantage of again by a marine mechanic.

Ben

[artdf175]

Where are you located
There maybe someone that can help find a honest mechanic