Prop suggestions after repowering with more horsepower?

I have a 19' aluminum hull crestliner phantom sst that was originally powered by a 115 evinrude and ran great with a 13 1/4 prop @ 17 pitch. I am upgrading to a new 150 etec (hrr hrr hrr as tim the toolman tailor would growl) and am looking for suggestions to help me narrow down the field to an ideal prop. Evinrude sent me a 17 pitch viper ss prop with this motor but I cant imagine that will be right (thinking I will need to increase pitch with increased hp?). I usually run aluminum props as I go where the fish go...."rockfish" that is. The boat is used for a combination of fishing and pleasure boating with limited water sports. I am looking for a good all-around prop but would lean towards fuel efficiency over 1 mph increase in top end speed or acceleration.

Ayuh.....I need some help Thanks in advanceView attachment 185911

Re: Prop suggestions after repowering with more horsepower?

There are many 150 engine tests listed on the Evinrude web site. If you review a few of them, I'm sure you will find some tested on similar size boats. They show the performance and what size/type prop used.

The 17" Viper may be more appropriate than you think, given the different gear ratios used between the 115 and the 150.

Re: Prop suggestions after repowering with more horsepower?

jestor68 said:

There are many 150 engine tests listed on the Evinrude web site. If you review a few of them, I'm sure you will find some tested on similar size boats. They show the performance and what size/type prop used.

The 17" Viper may be more appropriate than you think, given the different gear ratios used between the 115 and the 150.

Click to expand...

I had studied their prop selection charts and somehow missed the testing that you directed me too. Thanks! And perhaps the viper is the right prop, at least according to the test boats..... Now to find it in aluminum?

Re: Prop suggestions after repowering with more horsepower?

The Solas amita and Rubex are good props.jestor68 may be able to suggest a size.
Your dealer should let you try props till you find what works best.

Re: Prop suggestions after repowering with more horsepower?

The Viper is probably a performance wheel if SS. That could equate to a couple of hundred rpm and a few mph. First thing however is to find out the difference in gear ratios and then get a comparison on the old prop. I'm going to guess that the hub size is more like 4 3/4 on the new one vs 4 1/4 on the old. The new would swing a 14 ish inch dia prop where your old a 13 ish. In Mercury I know the splines and prop shaft diameter are the same for the 115 range of engines and the 150. Only difference might be the necessity of a spacer on the prop shaft to get the front to rear dimensions correct on the 150 to get the nut to lock. If you ran the old prop and got a reference that was close to what you are looking for, adding the extra inch wouldn't amount to that much; better low speed control and less top end and rpms.

If you were slightly high on rpms at WOT, like 100-200 then getting your 14ish x 17P alum might be the thing to do.

Best I can do with me here and you there.

Mark

Re: Prop suggestions after repowering with more horsepower?

TheHookUp said:

I had studied their prop selection charts and somehow missed the testing that you directed me too. Thanks! And perhaps the viper is the right prop, at least according to the test boats..... Now to find it in aluminum?

Click to expand...

A Solas Rubex 14.5 X 19 pitch would seem to be a reasonable equivalent if you want to run aluminum.