Motor compression results? 2001 Yamaha Vmax HPDI 200hp

[MassBass320v]

Looking at a boat with a 2001 (assumed) Yamaha Vmax HPDI 200hp. Owner says compression test results were 116, 116, 114, 112, 110, 98. I've read that they should all be within 10psi (or is it 10%?) of each other and one is a bit more out.

Wondering if these are acceptable numbers or should I walk away?

Thanks in advance.

[mactlman]

did you ask in the yamaha forum also? looks fine to me a de-carbon might equal them all out more?

[tj]

I had new boat dealer work on my 1997 2.5L Merc this spring; tune up, compression check, etc. All cylinders were 115#.

[MassBass320v]

did you ask in the yamaha forum also? looks fine to me a de-carbon might equal them all out more?

I did, not much of a response yet

[wmitch2]

I'd be concerned about the 98 ! Might want to get it Bore Scoped, may also have a bad reed too. I'd also start using Ring Free in each tank. When's the last time you changed Spark Plugs, check that low cylinder for fouling.

[MassBass320v]

I'd be concerned about the 98 ! Might want to get it Bore Scoped, may also have a bad reed too. I'd also start using Ring Free in each tank. When's the last time you changed Spark Plugs, check that low cylinder for fouling.

I don't own the boat, it's one that's for sale that I'm interested in (or maybe not depending on the motor!)

[Lightning 6]

Check them yourself.

[MassBass320v]

Check them yourself.

I'm not concerned that the numbers are not accurate, I'm just wondering if they are too far apart or indicate motor problems

[lpugh]

I'm not concerned that the numbers are not accurate, I'm just wondering if they are too far apart or indicate motor problems

Deduct the price of a powerhead from the asking price, if he does not agree, walk away

[MassBass320v]

Deduct the price of a powerhead from the asking price, if he does not agree, walk away

I'm srarting to think the asking price must already be reflecting this, although the seller hasn't outright admitted to it.

[Lightning 6]

I'm not concerned that the numbers are not accurate, I'm just wondering if they are too far apart or indicate motor problems

If you are not concerned about how accurate they are….then why be concerned at all. After-all, seller could be lying and/ or he could have performed compression test improperly.