Revolution 4 on 2520SL w/ F225, WOW!!!!

[channel_surfer]

Picked up a rev 4 (14 5/8 X 17) on ebay and it came today.

Threw it on the F225 after work. FYI, the included hub kit worked fine on the Yamaha F225. The only difference was that the hub kit came with a nylon lock nut and a metal tabbed cover to lock the nut for use on a merc outboard. We just reused the same Yamaha crown nut and cotter pin setup with the remaining parts from the included flo torq kit, which were thrust washer and hub inserts.

Took the boat out for a spin with the new wheel. We like it. Conditions were the same today as they were over memorial day weekend, windy with a fast 2' whitecapped chop.

HUGE difference in bite. Sharp turns in the creek can be taken now with absolutely no blow out. Was horrible before.

HUGE difference in trim range. With the stock prop I could SOMETIMES trim up to 5 bars on the meter, most of the time 4. With the REV-4, I can trim almost all the way up the meter and the boat just keeps gaining speed. Trimmed up to about 3-4 bars from the top of the meter before it blew out (thank you yamaha rev limiter!)

We were out all memorial day weekend, and I took note of typical readings with the stock prop...

Yamaha 17P factory installed prop:

4400R - 24mph - 11GPH
4800R - 28mph - 12.5GPH
WOT 5400 - 34mph - 15-16GPH

Today with the Rev-4, similar conditions as the numbers above:

Merc Rev-4 14.675 X 17:
4400R - 27mph - 11GPH
4800R - 31mph - 12.5GPH
WOT - 5400R - 35.7mph(best ever) - forgot to look at WOT GPH.

Needless to say I'm happy with the gains. The prop really grabs and there was no cavitation or blow out in the sloppy chop today, in any direction relative to the waves. Head, tail, quartering, just held great.

I was worried about WOT rpm with the 17P 4 blade, but I'm right where I was with the yamaha 3 blade. Good enough, a couple hundred more rpm would be good but 5400 is enough. Never run WOT anyway.

Big thumbs up for the REV4!

 

[channel_surfer]

Almost forgot, one thing we noticed was a vibration at about 3500 we could feel that was not there with the 3 blade prop. 3300 or 3700 and it's gone.

Might try to move the motor up a hole or 2 next time we pull the boat to see what if anything that buys us. We're one hole from the lowest now so can go up 2, I think.

 

[B-Faithful]

You can definately go up high with the rev4 and she will bite. your anti-vent plate should be right about the water line when running. slightly under with a bracket.

Glad to hear more Merc products are helping Yamahas perform better :lol:

 

[96TL]

Almost forgot, one thing we noticed was a vibration at about 3500 we could feel that was not there with the 3 blade prop. 3300 or 3700 and it's gone.

My Powertech 4-blade caused a vibration at 3200 RPM. Any lower or higher and it would go away completely.

Maybe its normal for 4 blades? I always thought they were supposed to be smoother.

 

[grouperjim]

I have heard that what some people think is a vibration is actually a resonance......meaning a certain metal part is being exciting at a particular frequency. What is resonating are one or more of the engine latches on the motor cowl. The remedy was just a quick lube of the latches and the resonance/vibration went away........worth a try.

 

[channel_surfer]

Well, went out today running heavy (full fuel, 7 people, gear, etc) and the 17P is a little too steep for my boat, only managed 5200R which is not where I would prefer to be. Going to try to go with a 15P, if I can find a buyer for my 17P. Posted it for sale here on classicparker and on craigslist.

http://southjersey.craigslist.org/boa/720064820.html

 

[B-Faithful]

try the 16" Enertia :wink:

 

[Porkchunker]

I was going to say...WOT rpm should be closer to 6,000. 5,800 would be safe.

Dave

aka

 

[B-Faithful]

I am much happier with the fuel burn and rough water performance with the enertia over my previous rev 4. Call Shorts marine in DE for merc props. Best prices around on new.

(yes Shorts Marine in DE is the dealer that lost Parker because they were pulling the Yamaha's off and replacing them with E-Tecs :lol: )

 

[fred]

B-faithful
What are your numbers with the enertia? I am looking to increase midrange performance and currently run similar numbers with the stock prop as posted by Chanel surfer.

 

[B-Faithful]

I dont have a parker or a Yamaha but on flat water I can hit 42mph according to the gps with regular load. At 4000rpms I can run 27-29mph burning between 9 and 10gph. I am running a 17" Enertia with a 1.75 gear ratio.

I was getting great flat water performance with a 17" rev 4 but I could only turn 5350rpms at wot (I wanted to be at least 5500 for max engine life). I also got horrible fuel mileage in rough water with the rev 4 and couldnt hold plane without ventilating at like 12-16mph. With the enertia, i can hold bite and stay on plane as slow as 12mph and I dont have tabs. My rough water mileage is also a lot better with the enertia.

 

[fred]

Thanks for the reply B-Faithful.

Chanel surfer did you pick up the 15p Rev 4 and if so could you post your numbers as i am trying to pick up a little more mid range.

 

[channel_surfer]

Nope need a buyer for the 17P first.

 

[channel_surfer]

OK so here's an update.

We had an 'encounter' with a 'sandbar' a few days ago. No real damage, we drifted onto it and I tried to power off for a while, ended up poling the boat off of it with a boat hook and a net. It was comical at least. Almost had to get out and push but not quite. Luckily my sea tow is paid up as well, though we didn't have to call them.

Anyway, sounds like I might have bent the tops of the prop a bit. Visually, I don't see anything, but my WOT dropped down to about 5100 and 31mph, as apposed to 5400 at 35-36mph. Made a couple trips and the new 31mph top speed was consistent.

Threw the yamaha 15X17 3 blade back on and it's back at 5400-5500 and 34mph.

Dad took the wheel to a local prop shop here in town. According to dad, the guy said that the rev-4 is an easy prop to bend. Said he can fix it, and take the pitch down to 16 or so (I wrote a note with the prop with my original performace numbers, numbers after the sandbar, and numbers I want ultimately if possible) for $150. Should have it back Thursday to report on it over the weekend.

Oops......

 

[TheOtherLine]

We had an 'encounter' with a 'sandbar' a few days ago.
Oops......

Depending on how much "powering" you did, trying to get off. You make want to check the impeller. If you haven't replaced it in a while, this might be a good time to do it. Sand wreaks havoc on impellers.

 

[channel_surfer]

Impeller was new this spring. Still have good telltale stream and haven't set off any alarms even with extensive idling. Probably change it again over the winter for cheap insurance.

 

[channel_surfer]

So got the prop back from the shop today.

Prop guy said it measured out at a 19P. Said there wasn't much damage to it other than having the edges nicked up a bit. He was only able to bring the pitch down to 18P since the prop is apparently 19P from the factory and the limit on stainless pitch change is 1". It was clearly stamped on the hub as a 17P.

Have not had a chance to run it yet, probably later tonight or tomorrow.

Said it was very common that most outboard and i/o props don't measure at the pitch they are advertised as being.

 

[TheOtherLine]

It was clearly stamped on the hub as a 17P.

Said it was very common that most outboard and i/o props don't measure at the pitch they are advertised as being.

:shock: What? :shock:

Uh, yes, I'd like to buy one of those 19 pitch props, just make sure it's really a 17 pitch, really... WOW.

 

[channel_surfer]

Took it out tonight.

Much better, with the motor trimmed deep I was spinning 5400. Trimmed out with 7/8 tank of fuel on the little bit of flat water I could find, it spins 5700-5800. Top end was 34.2. Engine sounds much happier at wot now.

Bay was very rough with the 20-30mph winds tonight, still managed a nice cruise at 4600rpm, 11gph and about 22-23mph. The little bit of running I did in the calm river showed just over 2.5mpg at times.

I trust my prop guy, it's a business that appears to have been here for quite some time now and he definitely took the time to talk to me for a good 10-15 minutes when I picked up the prop. I've read elsewhere accounts of folks having new props checked for pitch and them being off. I'm just suprised this one was off a full two inches. Regardless, the new "18P" seems to have done the trick.

 

[channel_surfer]

I'm done!

Took her out today for a fishing trip in the bay. Four adults, one 5 year old, poles, couple coolers, about 3/4 tank of gas. Reset the trip meter on the GPS and the trip flow on the navman. Travelled 15.6 miles on exactly 6.0 gallons of gas for an average economy over the trip of 2.6mpg. Very happy with that.

WOT was 5700. Forgot to look at max speed but I'd guess around 33-34 or so. Boat is most efficient around 4800rpm. At 4400 it's going about 23mph and burning about 11 to 11.5gph. Up it to 4800 and the boat gains about 5mph up to 28-29mph and GPH is still in the high 11's.

Going to keep the prop now, it's perfect. Also the vibration I had at 3300 before is now totall gone after the re-pitch. Boat also carves some awesome turns, even with the motor up 4 or 5 bars on the meter there is no blow out at all, just leans waaay on over and cuts the turn. This was my biggest complaint about the 3 blade, it was useless in any kind of moderate to high speed turn.