Reply With QuoteA 2010 model should run 6000 RPM at WOT. You are loosing power when you run more than that. If you go to a prop with 2" more pitch it should get you down to about 5900RPM. Better for your motor and you should gain a couple MPH.
Likes: 0
Thanks: 0
HaHa: 0
Crappie Wall Hanger II
yamaha 115 4 stroke
what rpm should this be at wot. 18' war eagle 861. its turning 6300 at wot, [44 mph] should i change the prop?if so what would this gain me? thanks
Super Mod and 2014 Crappie.com Man of the Year
* Crappie.com Supporter
A 2010 model should run 6000 RPM at WOT. You are loosing power when you run more than that. If you go to a prop with 2" more pitch it should get you down to about 5900RPM. Better for your motor and you should gain a couple MPH.
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va
Crappie Wall Hanger II
Super Duper Moderator - 2012 Crappie.Com Man of the year & 2018 Crappie.com Decade of Exceptional Service Awards
* Crappie.com Supporter * Member Sponsor
17 is the pitch .....13 1/4 is the diameter.......You need to try a 13 1/4 X19 that should do it.
I have spent most my life fishing........the rest I wasted.
PROUD MEMBER OF TEAM GEEZER
PICO Lures Field Rep
Crappie Wall Hanger II
Crappie.com 1K Star General
I'm there too, in the neighborhood of 6200 or so with a 90 hp Yam 4 stroke, with a 16p @ ~39mph, trimmed out in perfect conditions. I am looking for a good used 18p Power Tech. I am wondering if a 19p would drop it too far. It's on a WE 860.
Crappie Wall Hanger II
As a yamaha outboard tech, I would suggest not changing props. The rpms will only go down as you load your boat with gear and friends. These 4 strokes were designed to run high rpms. If you do go to a higher pitch prop, you will probably not like the hole shot and acceleration. Another thing to consider is that not all of these motors have been equipped with knock sensors. Which is pretty important with today's fuels. And, could lead to engine failure due to over propping, a none warranty engine failure. Good luck and stay safe.
Crappie.com 1K Star General
Why is the recommended rpm range 5000-6000 if it needs to run ~6200?
Background on mine: fish alone most of the time (when the 18p will be used), but will keep the 16p to use during duck season when the speed is secondary to the ability to get a load up and moving
Super Mod and 2014 Crappie.com Man of the Year
* Crappie.com Supporter
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va
Crappie Wall Hanger II
Well, you've kind of answered the question in a sense. If it runs 6200 with just you in it. Adding a second fisherman and gear will bring the rpms down. The extra 200 rpm will not damage anything. As far as props go. The terms we all grew up with in the performance sector was cup, double cup, forward rake, aft rake and of course, pitch. Well, with 4strokes. You can throw all that out of the window. The 4strokes of today (at least) do not have the torque values down on the lower end of the rpm range. Because of that, the designers intentionally raised the rpms on the top side. So that a lower pitch prop could be used to gain satisfactory 'hole shots' and spin fast enough on the top end to still give a decent top speed. Now with that said, today's fuel is NOT the fuels we used back in the days of high compression, fire breathing 2 strokes capable of more Hp than displacement. Today's fuels are prone to deteriorate fast. Too fast for the average boater. So, if you go with the 18p prop and bring the top end r's down abit. You'll most likely not like the hole shot. And, a bad batch of fuel will be more prone to detonation in the engine due to the load factor placed upon the engine. I'm not saying you will absolutely not like the 18p and will toast your engine in short order. But knowing what I know, I'd just keep running what you have and spend that extra $$$ on a new depth finder or something. Thumbs UpOriginally Posted by talltimber
Posting Permissions
