325 OS 4 blade props

blb078 · Postby **blb078** » Fri Mar 06, 2020 1:40 am

Just seeing if anyone has or know of anyone changing the factory 3 blade props to a 4 blade and if they saw any better fuel efficiency with a 4 blade? If so what size and pitch was used. I know if I did this I would probably lose some on the top end but I'm ok with that just wanting to see if there was any better fuel consumption with a 4 blade. Thanks

SlushC310 · Postby **SlushC310** » Mon Mar 09, 2020 7:58 am

Which engines (probably Yamaha 300s?) and which props are you currently running? I have Yamaha 250s with SWS II 15.25x19 three blades on my C310 and have been considering the power tech OSF4 18 pitch. I spoke with one gentleman that has a 3070 walk around and he said the 18 pitch 4 blades were amazing; he had the same setup I have. Said he suffer a few mph on top end and of course his RPMs changed, pretty sure he said 300-400rpms.

Gregoryton · Postby **Gregoryton** » Mon Mar 09, 2020 1:46 pm

Are 300-400rpms normal all things considering?

blb078 · Postby **blb078** » Mon Mar 09, 2020 2:21 pm

Yamaha 300s, they have 15.5x17. I was thinking something like this in a 15 pitch. https://www.ptpropeller.com/Powertech-w ... ler-yamaha
or even this, it's a .25" smaller though, maybe a prop expert can chime in . https://www.ptpropeller.com/content-pro ... amaha.html

SlushC310 · Postby **SlushC310** » Wed Mar 25, 2020 9:01 am

So I gave PowerTech a call (awesome customer service!!!) and after a 30min conversation and sharing a lot of my vessel info, RPMs, engine data, etc...they 100% feel if it would be best in my case to go to the OFS4 17p. I would drop a few MPH off top end of-course, but it should provide the stern left I'm looking for and the ability to plane off at 4-5mph slower.

Please let us know the results if you try anything.

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