Yamaha F90 WOT/Prop question

Angr777

Recruit
Joined
Sep 6, 2014
Messages
1
I am pretty new to this whole thing so hopefully someone can educate me.

My RPM rating for my motor is 5000-6000. I assume this means my WOT rating is max 6000 RPM. Knowing this, should I be trying to get a propeller with a pitch that will get me to 6000 RPM at WOT? Currently I have a 13.5 x 15 which when I floor it takes me into the 7000 range. Should I only be taking it to 6000 and that's that or should I be looking for a higher pitch to lower my RPMs at the full throttle? Thanks for the help!

G3 V162F with Yamaha F90
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
It would help to have your gps speed at wot; but assuming the tach is accurate and based on the many Yamaha G3 tests
You need to knock 1000 off the rpm. That would indicate a 20" prop.
You may want to look at "yamaha performance bulletins". There are 1 1/2 pages of G3 tests.You should be able find a set up close to yours.
 

gajomac

Recruit
Joined
Sep 6, 2014
Messages
1
7000 grand Yikes!!! I deffintly agree with Steel you need to lower your RPM's in a bad way,, First thing i would ask is were do you use your boat the most Offshore or lakes/rivers A good choice of standard sizes would be 19 for offshore or a 21 for lakes/rivers I just got home from the lake testing out a new prop for my 22 Angler I took a big swing at my rpm's, I went from an aggessive rake 3 Blade 21 to a standard rake 4 Blade 17 Solas. I went from a WOT of 4800 to 5900 on a 200 Yamaha and only lost 4.5 mph's
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,804
Let's back the truck up. You said when you "floor it". Is that immediately when you are trying to get the boat to "plane out" aka "hole shot"? If so you are ventilating and need to correct that. The rating of 6000 is under the normal load you have in the boat when running as fast as it will go in mph at WOT.

Mark
 
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