Propping a 300 Marlin with new Yamaha F300 XCB's

[Pat Hurley]

Question for any Marlin owners with the Yamaha F 300's ...are you happy with the SWSII 15 1/2 X 17's which seem to be standard issue ? or did you go with aftermarket props ? Were the stated factory performance numbers realistic ?
I am in the process of repowering my 300, trading in the 250's removing the infamous aluminum cap, addressing any moisture issues than glassing it over. Going to have the plastic deck drains replaced while at it too.

Thanks in advance !!

 

[athomp228]

I cant give a good answer, I have only had new 300's for 5 months and haven't paid too much attention to the #'s but I can say my WOT is 5600 RPM and nowhere close to the 49.5 MPH top speed Grady claims. My top speed is around 35-36 MPH @ 5600 RPM and cruise is around 28 MPH @ 4500.

 

[Steven Brewer]

Has anyone put a long shafted trolling motor on their GW282 Sailfish ?

 

[Pat Hurley]

I cant give a good answer, I have only had new 300's for 5 months and haven't paid too much attention to the #'s but I can say my WOT is 5600 RPM and nowhere close to the 49.5 MPH top speed Grady claims. My top speed is around 35-36 MPH @ 5600 RPM and cruise is around 28 MPH @ 4500.

Wow those numbers are disappointing to say the least. A friend of mine has the 300's on his 33 express with much better results than yours.

 

[athomp228]

Wow those numbers are disappointing to say the least. A friend of mine has the 300's on his 33 express with much better results than yours.

Yea, why I'm in interested in this thread. I will say when testing WOT in calm bay conditions the bottom was not clean and when I started to take note at cruise in calmer ocean conditions I did have full water and fuel tanks. Probably something I should have kept a better eye on this year but was just excited to use them coming from 225's and using all of the features the DEC offer.

 

[Automated14]

I cant give a good answer, I have only had new 300's for 5 months and haven't paid too much attention to the #'s but I can say my WOT is 5600 RPM and nowhere close to the 49.5 MPH top speed Grady claims. My top speed is around 35-36 MPH @ 5600 RPM and cruise is around 28 MPH @ 4500.

I suspect you need different props or engine mounting height... if you have a 30 marlin like the OP.

I have 300's on my 330 express and your numbers are about what I got with the 3.3 liter 225's that came on the boat new in 2004. I repowered with 300 V8 verados and I can cruise 32/33mph at 4500. WOT i've tickled 43mph.... and that's with a really tragic bottom that looks like the surface of the moon.

 

[kirk a]

Repowered my 330 with 300's 2 years ago, this year went from the 17" props which were original from the old 225's and dropped to 15". Saw significant increases in performance with the prop swap. Top end did not change a ton 40, and WOT is 58-5900. Cruise at 24kts.

I'd definitely look at different props, and recommend contacting Ken at prop gods. My numbers are pretty darn close to the published bulletins.

 

[athomp228]

I suspect you need different props or engine mounting height... if you have a 30 marlin like the OP.

I have 300's on my 330 express and your numbers are about what I got with the 3.3 liter 225's that came on the boat new in 2004. I repowered with 300 V8 verados and I can cruise 32/33mph at 4500. WOT i've tickled 43mph.... and that's with a really tragic bottom that looks like the surface of the moon.

@pat sorry to highjack your thread.

Pic of engine mount height (rafter came out for fresh paint). Is this is a normal mounting height?