posted 05-08-2010 09:49 PM ET (US)        

1988 18 Outrage with bow, side, and stern rails.
Yamaha F115 and F9.9 high thrust
Galvanized dual axle trailer.
NO BOTTOM PAINT
Mills canvas, bimini, front shelter, mooring...

Time to retire my 1998 Alert/Montauk with Merc 90 4-stroke.

Now my question.
Took it out on the Bay today. 3/4 full tank, kicker, batteries in splashwell (soon to be moved), 2 adults and 2 kids. Prop is black Yamaha SS 16" with vent holed.

A little slow to plane. Get it going and hit 31knots and was bouncing off the rev limiter at 6100RPM!
The guy I got it from was not into speed.

Now the question. What prop should I be running? The batteries and going into the console this week, and so are a set of Lencos.

I read a 17" works well, but there was somef throttle left before hitting 6100.

Any suggestions?

BTW, we trolled a few hours for 2 halibut, 10 & 15 lbs.

posted 05-08-2010 10:41 PM ET (US)            

Tony (aka elaelap) had the same engine and model and hit ~40 mph with a kicker and baitwell etc.

I am thinking a 19k in a Yamaha propeller.

Here is a long and technical thread from Tony on his prop selection/evaluation with comments from Tom Clark and other propeller veterans.

http://continuouswave.com/ubb/Forum4/HTML/004093.html

posted 05-09-2010 12:51 AM ET (US)            

The motor has a Doel-Fin, but I'm gonna remove it and try running. Then trim tabs. Then move batteries. Then...?

When propping my Merc 90 4S on my 17 Alert/Montauk, I literally tried 7 different props. Don't want to do that again!

posted 05-09-2010 05:04 AM ET (US)            

Then you can start working on rod holders, live bait tank, electronics, moving the batteries :)

If you're not already, you should come to the nor cal rendezvous in a few weeks! Look in the "Rendezvous" section for details. It's on Sat, May 22. Maybe the fishermen can fish after the cruise and lunch.

posted 05-09-2010 12:24 PM ET (US)            

Have my Kodiak Pro Flow 17 from my other Whaler.
IMHO, all boats can benefit from trim tabs. Had them on my 17. Invaluable! I'll post a link to some pics later. Trick bait pump install. Plastic through hull w/strainer scoop on tab.

Splashed the boat at Oyster for 2 halibut (10&15) for a couple hours with my kids. They love the forward shelter!

posted 05-09-2010 07:04 PM ET (US)            

My point: you should be getting at least into the high 30s with just about whatever prop you have on that rig, and if you're not, something's wrong. I'm going to use the search engine here and get some more reliable stats, BTW...at my age, better not trust my tired memory, but I'm pretty sure the info given above is close to correct.

posted 05-09-2010 07:14 PM ET (US)            

As you can see, I spent two-thirds of my time trolling with that motor, and only a tiny amount at WOT, so I don't know how significant these data are.

I'll dig around for something more relevant after a while.

posted 05-09-2010 11:31 PM ET (US)            

OK. The prop is a Yamaha black SS stamped 16K.
Now here is the odd part. There are vent holes drilled in it. They are in the correct place they normally would go. I did not know Yamaha made this prop with vent holes.
They look stock.

My one time running this impressions.
Super torquey. Will literally throw you. Reminds me of the old Merc inli e six.
Slow to plane. Lots of weight in back. Prop did not cavitate or slip.
Once on plane, ran steadily up to the rev lmiter at 6100 om the Yamaha tach. Pulled throttle back until RPM dropped motor stopped cutting out. 31 knots.

I have my props off my Merc 90 4S to try out next when I get a new aft washer.

posted 05-10-2010 12:13 AM ET (US)            

I've spent countless hours perfecting (for me) my 17 Alert/Montauk with a Merc 90 4S. I hope to carry over some knowledge from that, but this a different type of horse.
I can use all the help I can get!

Thanks all, especially Tony.

posted 05-10-2010 02:33 AM ET (US)            

My 18' had twin 70hp Yamaha's which according to my performance numbers performed very similar to a single 115. I was only able to reach 52-5300 rpm when lightly loaded (5500 max). With two other guys, my Kodiak PF-17 filled (good choice in bait tank by the way haha), rods, fish, etc, I could only get upper 4000's. Still, I never really considered the boat to be "slow" to plane. Maybe 4-5 seconds w/ lots of weight on her. I guess we should know what "slow' means. 4 seconds? 7 seconds?

posted 05-10-2010 03:47 PM ET (US)            

That may explain the high RPM. Since blade was not designed for vents, maybe it's causing it to lose it's bite?

Any coments in a stiletto 4blade 16"?

And that pump mount looks good. Just dropped the boat off to mechanic. Owner walks up and comments how trick it looks. Calls a couple other guys over. "who's idea was that?"
"mine! But I haven't tried it yet. Should work. "
Wow! I may have actually done something right!
Picture link soon.

posted 05-10-2010 04:18 PM ET (US)            

Looks like I didn't go down in prop pitch 'til the end (when I sold the boat the motor had ~760 hours), and I only went down one inch. So much for my remembrance of things past...five years past, anyway.

Hope some of this helps, FISHNFF. I bored folks silly with reports about that boat/motor combination -- oftentimes responding to "underpowered" criticism from those who had never experienced the rig -- and a local search will dredge up many threads (maybe too many) about my experiences with Cetaceous and her F115. Would I do it again? In an instant, for my kind of use. Perfect match.

posted 05-11-2010 08:56 PM ET (US)            

Will report back with results.
Thanks all.

posted 05-13-2010 03:30 PM ET (US)            

Most propeller models that do come with 1/4" vent holes have them drilled after the prop is cast. Propellers with vents like Mercury's PVS have the (much larger) vent holes cast into them.

I would not expect a Yamaha Painted Stainless Steel propeller to need vent holes in this application.

An Outrage 18 with a stern weight bias may benefit from a good stern lifting propeller. The Yamaha Painted Stainless Steel propeller model is a good stern lifter with its semi-cleaver design.

posted 05-22-2010 08:09 PM ET (US)            

Blew a steady 15-20 no matter where we went, and cold! 2'-3' whitecaps.
Pulled the prop from my 17 Montauk and Merc 90 4-stroke with a 2.07 lower end.

Test
17" Ballistic SS
1/3 fuel
Batteries in console
Yamaha F115 and 9.9 HT kicker
17 Gallon bait tank
3 1/2 persons

The Lenco's were mounted and functional, but switch panel was not mounted, so hard to adjust.

Ran in the most protected area (not by much) and was able to get the boat up to 34 knots at 5900 RPMs. Not the greatest test day, but for just a seat-of-your-pants feeling, the boat ran great.

Planing was quick and smooth.
I could not turn at speed, due to the weather, but I ran it into, with, and across the waves/wind wide open. Stayed dry with little pounding . No jarring like the 17. Actually seemed to pound less going quartering into the waves than our 22 Grady 226 SeaV2!

It took some trimming to get the last few knots and few hundred RPM's on the top end.

Next, the motor gets raised up another notch, from the second to the third. I may keep the Doel Fin. On my Montauk, it seems to keep the prop from blowing out.

FISHNFF

posted 05-22-2010 09:31 PM ET (US)            

I think you are wasting efficiency by having a doel-fin and trim tabs. Typically doel-fin's are cheap fixes when you don't want to spend the money for the tabs, I would get rid of it as it doesn't really serve much purpose.

posted 05-22-2010 10:28 PM ET (US)            

I've run all my whalers with and without Doelfins. This one had it on when I bought it last month. On my 17, I have it up on the 3rd hole, and when on plane, the fin is clear of the water. Only in the water working at slower speeds. The boat would occasionally cavitate trimmed up and turning. With the fin, no problems.

I'll try working with this boat, piece by piece. I've gathered tons of info from this site, especially Tony.

Hoping for nicer weather. Rain in the weeks forcast agaIn.

posted 06-18-2010 03:03 AM ET (US)            

Ran the 17" Ballistic with 2 aboard, full fuel tank, 9.9 4S kicker.
With almost full trim and a touch down on the trim tabs to eliminate porpoising, I was able to average 35.3knots up and down the Alameda/Oakland estuary at 5900 RPM.
Trimming further to 6000 got the prop to slip. I was not able to get it to blow out. At high speed turns, I was able to get the boat to slide while turning.
Cavitation, or more correctly, ventilaton was almost non existant. Held on great in slower speed turns. Acceleration was brisk. Downright good with trim down.

I'm a happy Whaler guy! I also dropped of my old 1998 Alert/Montauk at the dealer, and have had multiple offers by mid afternoon. Sad to see it go, but this Outrage is nice!

This same prop on the 17 and Merc 90 did the same speed at a few hundred less revs, but higher gear ratio. These Ballistic props are nice!