Fuel Burn”Twin 150’s Ocean Pro’s

Irish Wake said:

I have the Dusky 256fac with Twin 150’s Ocean Pro’s Carb’s with only 300hr,trying to see what the average Fuel Burn should be at Cruising about 4000rpm,GPH or MPG over all,over the Winter Im putting a Fuel Management System in would like to know what to Expect, Would Appreciate all Info

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Murph, if she's proped right you should be seeing pretty close to 2mpg. Too many prop those 150 Eagles too high. Those engines put out their best power proped to turn 52-5300.. The 175's to can twist out to 56-5700, but the 150's do better 4-500rpm lower.

We can check this when I look at her in March.. I'd really like to see the props you have along with engine heights..?

A rule of thumb is 10% of HP = GPH at WOT. So, your 150 HP motor will consume about 15 GPH at full throttle. You have two so that is 30GPH at full throttle for both. It will drop a lot and lower throttle settings.

For got to mention there 4 Bladed Prop,

Not to hijack but I have been thinking of re powering sometime in the future going from a single 225 to two 115 or 150's (max for boat is 300), would like to know if I can expect double the fuel (oil if 2 stroke) burn or about the same since its the same amount off HP driving the boat?

Team Dougherty said:

A rule of thumb is 10% of HP = GPH at WOT. So, your 150 HP motor will consume about 15 GPH at full throttle. You have two so that is 30GPH at full throttle for both. It will drop a lot and lower throttle settings.

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I had them on a Mako258 and burnt about 30/hr going 25 knts in the low 4's.

Also, there was a manufacturing defect on the block casting on these motors (mine were 1994's) which resulted in the port motor going caput after overheating once (got a plastic bag around the lower unit).

I had a pair of 1997 150's on a 26' Seaswirl. I would cruise in the mid 20's at about 4000 rpm's and the combined burn was less than 1 mile per gallon - she loved to drink. I moved up to a boat twice the weight with fuel injected 250 Yammi's and had better economy.

I can say in 9 years of running the Ocean Pro's I never had a bit of trouble.

Those engines are gonna be more thirsty than an irish girl at a pub on ST Pats day!

Those Dusky's are lots easier to push than Mako's or Seaswirls. They have a deep entry out near the bow, but flaten out to fairly flat modified V at the transoms. That why I was saying to put the biggest tabs possible on it. Get the bow down in the water and she'll ride great.

Team Dougherty said:

A rule of thumb is 10% of HP = GPH at WOT. So, your 150 HP motor will consume about 15 GPH at full throttle. You have two so that is 30GPH at full throttle for both. It will drop a lot and lower throttle settings.

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Carb 2 strokes are a little worse than that. About 60% of WOT at a cruise of 4000 rpm. So about 18 -20 gph would be my SWAG. Maybe 1 nmpg if the hull is not deep vee. YMMV

Those engines are gonna be more thirsty than an irish girl at a pub on ST Pats day! "Ouch"
at 4000 rpm she run’s 26 knots,Im hoping to get 1 1/2 MPG for running off shore this season,if not I'll be looking into New 150's or most likely 200's

I Appreciate all the Info Guy’s,

hey murph, us carb guys might not get the best fuel economy, but when i hit the key i know she'll start...............everytime :thumbsup:

Plus you will not save the money in gas that it costs for a new engine. Use them until they die (unless you don't hold enough fuel to get to were you want to go).