recommended props

[jaxbroker]

I have twin 175 Evinrudes on a 24' Wellcraft Flybridge. They currently have stainless 14.24 x 23" (3-blade) props and get terrrible low end performance and even worse fuel economy. I trimmed the boat for max speed and reached 43mph at wot at 4300 rpms. I know I need to drop the prop size, but what size should I go to? Since I mostly use the boat offshore for bottom fishing, I am not very interested in max speed and would prefer better fuel economy.

 

[ob]

Re: recommended props

I'd consider dropping back to 19" pitch props.Are your current engines set to optimal height on transom?Anti-ventilation plate of engine lower unit should be roughly even with bottom of boat when trimmed level.Your max rpm should be 5500-5800 at wot.

 

[jaxbroker]

Re: recommended props

They are on a bracket and are height adjusted as you mentioned. They are 1986 engines with the VRO removed. I am getting about 0.8 mpg right now, just cruising at 3000 rpm with a normal fishing load in nominal seas. I know it has to get better than this.

 

[rodbolt]

Re: recommended props

wow at 4300 rpm's either an engine is way down on power or more likely it is way over propped. I think19 0r even 17 pitch would put your WOT back in the proper range. I dont know the year or block configuration of your 175's but you can figgue about 17 gallons of gas per hour per engine at anything above 4500 rpm.check all the basics but I am sure you have to much prop. if it is then dont push the engines. running overpropped can lead to detonation problems. we dont like detonation problems.anyway keep us posted I would like to see what prop size you end up with.