What can I expect?

[ed72vette]

I have a Yamaha 90 hp 2 stroke on a 18' Sailfish cc, total wt 2200#. This boat came with an alum. 17p prop. This set up would do 37 mph at 5300rpm. Tried several SS props of various pitch. The one that has worked the best so far is Power Tech 14x13. This prop give a good hole shot and pulls good at all rpm. Top speed is 34mph at 5600rpm. <br />I am going to try a 131/4 x15 Turbo 1. What can I expect from; hole shot,top speed [rpm and mph]and what would the characteristic differences between the 2 props be?<br />Ed

 

[Dhadley]

Re: What can I expect?

You can expect that Turbo to like a higher X dimension than the alumimum prop. By quite a bit. Kinda surprised the PT didnt also.

 

[ed72vette]

Re: What can I expect?

The boat came rigged with the motor in the fist hole. I moved the motor up to the 3 hole with the PT [part #YM90MQF3R13S]. The alum was only used in the first hole. The Turbo looks like it has a larger rake to it. Do you think the rpm drop will be more than 2oo rpm? This motor does not seem to like to go beyond 5500rpm.<br />Ed

 

[Dhadley]

Re: What can I expect?

Youre comparing 3 props that are designed totally different. If the 13" PT turns 5600 and is not on a limiter then the 15" Turbo should turn 5200. I wouldnt be surprised if it drops slightly more. Should be an interesting test. <br /><br />Good job on keeping track of the numbers. Just watch the water pressure.

 

[ed72vette]

Re: What can I expect?

Tried the Turbo 15p today. As Dhadley said 5100 rpm 37mph with motor in 3 hole and trim up fairly high. Is this to low an rpm for this motor? Wish the rpm were higher.