2005 150 Mercury Optimax XL 2.5

gwwannabe

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Can anyone tell me about these motors? I'm interested in a boat with a pair of these engines and I'm comfortable with everything except these motors. Based on info I found on the internet, I believe it's fuel injected and roughly equal to the Yami HPDI. Is this true? Are they fresh water motors or salt water? Anyone have first hand knowledge of reliability, noise level, fuel burn at cruise, oil consumption? Any special requirements, like high test fuel or special oil? What's the life expectancy in hours?

Thanks
Gary 89 Overnighter
 

Shutterbug

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No mechanic here so keep that in mind.

I've a pair of 03 Merc. 150 Opti's.

It's my understanding that they're nowhere near the pressure of the Yamaha HDPI"S. So what does that mean? Maybe someone else can explain.

I've burned 87ocatane and nothing else. Oil? I've only used Mercury DFI, as reccommended. Noise? Compared to what? Buddy has twin 200 Yamaha HDPI's, mine are louder. Compared to 4 stroke? No comparison. Oil consumption? I use more than my buddy does. Fuel efficiency? I'll put the 150's up against any other engine, 2 or 4 stroke. Normally get 2.5 n.m. per gallon in Chesapeake, and 2 n.m. in ocean. BUT, then the oil needs to be figured in.

Forgot! It's my understanding there's no difference between the Merc saltwater and the other, just the color of the decals.
 

gwwannabe

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Thanks for the reply, Shutterbug. What boat are your motors on? I'm getting about the same fuel consumption with a single 200 hp Johnson carb'd motor on my 20' Overnighter and the boat with these motors is a Gulfstream.

Gary
 

gw204

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The 2.5 is a proven block. Merc has been using it since the early '90s in carbed, EFI and Opti form and by 2003/4, the bugs had been worked out of the Optis. So, if they've been maintained, they should provide years of service.

HPDI is only marginally more efficient than EFI. Not so w/ Opti. It's a dramatic improvement.

The are only two negatives that I can think of. One is noise. They're loud! The other is resale. 99% of people shopping Grady want Yamaha. That's the only reason I bought them for mine...