News:

Welcome to the largest gathering of ARIMA boat owners anywhere. We are a forum based gathering of Arima Boat enthusiasts that like to pleasure cruise, fish, camp, and hunt. While Arimas are centered in the PNW, we have members across the globe. It is 3/4's water after all. Lurk, join up, and post about your Arima upgrades, family trips, and of course, your fishing exploits. Just remember to add photos whenever possible.

Main Menu

Propping a Yamaha F-70

Started by Chief of the Boat, October 07, 2012, 02:12:08 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Chief of the Boat

I installed the network cables from the F-70 to overlay the engine data on the Lowrance HDS-5 Gen II.  I took the boat out yesterday and here is the data I recorded with my current prop a Solas Titan 3 Blade Stainless 13.75" dia. X 13" pitch.  
RPM   GPH   MPH
4102   3.22   15.7
4363   3.43   18.6
4539   3.57   19.3
4703   3.83   21.2
4910   4.31   23.0
5008   4.46   24.3
5203   4.94   25.5
5434   5.21   26.7
5734   5.86   28.6
5875   5.94   29.6
The F-70 is a great motor that is basically a high reving 50, I am concerned that I am not hitting at least 6000 rpm at WOT(rpm range 5300-6300).  Grizzle is offered to let me borrow his Powertech clevered S/S prop.  I plan on spending a day at Kitsap Lake and do some prop testing with my two other props and Grizzle's, I also will be adjusting the Smart Tab settings.
Terry


redbaronace

The guy at Three Rivers Marine said that a range between 5800 and 6000 is where the RPMS should be on my 115 Yamaha.

Grizzle

Nice Data!  I'm guessing the 13" powertech will get you to the redline since it does on mine and we run heavier.  But you sure running nice there with a 5000 cruise @ 24mph and 5.4mpg.
Brook Stockton - My Boat: Mighty Molly - The Fish Monger - Arima SeaChaser 16 - Soft SkipTower and "The Rack"

SALTBOSS™ MARINE - Offshore Marine Products & Fabrication - http://saltbossmarine.com - brook@saltbossmarine.com - 206-953-SALT (7258)

Markshoreline

Chief, on my new 115 the max RPM's have steadily increased and now are at 6000 with the same prop that originally would only put out about 5300 rpm.  I guess it is getting broken in and a bit looser.
How many hours on yours right now?
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Chief of the Boat


Markshoreline

Yours should be loosened up by now.

But you have to realize that 5875 is 98% of 6000. Pretty close and questionable cost benefit to buy a prop for 2%!

Mark
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Chief of the Boat

We sea trialed loves whitecaps last Saturday on Hood Canal with Brooks PowerTech prop and the new kicker bracket(Thanks Brook & Eric),  both performed flawlessly.  The Yamaha F-70 rpm range is 5300-6300, the two out of three rule I always use about asking for advice resulted in the three plus dealers telling me that 5800 rpm is fine.  The folks at PT props an American company in Louisiana were very persistent that 5800 is too low, you need to hit at least 6100.   The motor sounds awesome spooled up at 6300rpm, and has a great hole shot and does not porpoise when trimmed way up.  My American made PT prop arrived yesterday; it is a work of beauty like the SaltBoss stuff.  Got skunked crabbing.
:applause:
Terry

Grizzle

#7
 :cha:

Terry I'm glad the prop worked out for you.  It took a while for me to get used to hearing that motor howling back there when we're running hard but I love it.   That motor loves to spin up.   
Brook Stockton - My Boat: Mighty Molly - The Fish Monger - Arima SeaChaser 16 - Soft SkipTower and "The Rack"

SALTBOSS™ MARINE - Offshore Marine Products & Fabrication - http://saltbossmarine.com - brook@saltbossmarine.com - 206-953-SALT (7258)

Chief of the Boat

Looking at all the Yamaha performance bulletins and the minimum WOT rpm with a F-70 is 6100 on a pontoon boat.