Props for 265 with 225 4 strokes

[jekyl]

Thanks for keeping an eye out Bill,

They are sending me some more 4 blades to try.I am getting ok figures with these props and everyone assures me the engines economy will get noticeably better in 50 hours......

I was going over your figures again and thinking that maybe 18' is the magical pitch.

My mechanic reckons the props I have are fine and that you want to run the biggest props you can for average running.....whatever that is.

 

[Bill_N]

The only thing I've seen is that there are a few times when I wish I could plane a couple kts slower in the slop. We did a long offshore run again last weekend and ended up running back thru 4-6' seas for awhile. 22-24 kts would've been ideal but the boat wants to run 24-26 kts and we were slamming once in a while so I was playing with the throttles a lot.

I might put the 17's on for the rest of the season and see how they run.

Bill

 

[JUST-IN-TIME]

your tech means

you want to run the biggest diameter props and pitch

in terms, means the bigger the bite the less slip, but this is not always true!!

especially with SOLAS props!!!!!

 

[jekyl]

Bill, you said that 3900 rpm seems to be your most economical revs. Can you give me an idea of what speed that would be, with one full tank and an average load in ideal conditions?

My motors came with the new square gauges and after refilling my fuel usage is within 1-2 litres of the gauge....cool.

If you throw the 17" mirages on I would be extremely interested in the results....


cheers haydn

 

[Bill_N]

3900 rpm = 29-30 mph with the 18's

 

[jekyl]

Something I have noticed is when I flush the motors on the trailer there is a small amount of black carbon soot washed out of the props as well as a black carbon stain from the black rubber exhaust port on the back of the motors. Motors have both done approx 20 hours now. Does this sound normal?

I never had any such thing with either the 200hpdi's or the previous boats Honda 150hp's.

 

[JUST-IN-TIME]

yep

called a 4 stroke

 

[jekyl]

That may be normal for a Yammie 4 stroke Richie but if so why did my Honda's never have any stains or soot at all....

 

[JUST-IN-TIME]

250's right?

 

[jekyl]

No 150 vtec's on a cat.

I have another query, When i study the Grady/Yamaha performance bulletin , in which they use 19" SWS 3 blades they acheive 6,000rpm and 50.5 mph with an optimal cruise at 3,500 of 2.13 mpg and 28 mph.

This seems optimistic at best. Has anyone acheived these figures?

 

[JUST-IN-TIME]

im talking about your yami's now?

Honda only makes a 225

 

[jekyl]

F 225's richie. with 20 hours on them now.

 

[Kenlahr]

Haydn; I have never noticed anything like that on my F225's. However, I had just over 80 hours on them when I got the boat. Not sure if it's breakin related..?

 

[jekyl]

They seem to be using more fuel than I would like. I wondered if the carbon meant they are running too rich?
The local techs are saying the fuel economy will improve with run in. But I'm expecting a more than 10% increase given the numbers on the Grady/ Yammie performance report.
I can't believe fuel usage would decrease this much after run in?
What props are you running Ken? And if you have a fuel management gauge what is your expected fuel usage at 4000rpm?
Thanks Ken

 

[Kenlahr]

Haydn I am running the saltwater II yamaha props that came with it. I went theough a series of props on my Gulfstream and ended up never getting better performance and ended up with what I started with.
-
I usually run around 3600 to 3800 rpm which is about 24 to 26 kts and I am burning less than 16 GPH. Up around 4k I will be burning around 19 GPH and pushing 30kts. Probably not exact, but close. I have noticed that pushing the Sailfish over 4000 rpm offshore I start sucking gas. I'm up over 30 kts, but ya come off a wave and ya feel it!

 

[Bill_N]

I don't believe the F225's on a 265 or 282 can achieve anywhere near full rpm with 19 pitch props. One person, 30-40 gals of fuel, no bottom paint and a tail wind - maybe you can get close.

With the Mirage Plus 18's I can get to 5800 rpm with 1/2 tank of fuel and 3 guys.

 

[Kenlahr]

I have 19's on my 282 F225's. At WOT get 5600 rpm and I am right at 49 MPH. I had about 100 gal of gas, a full tank of water and 2 people on board.

 

[Bill_N]

I think you'd be happier with a set of 17's or 18's.

 

[JUST-IN-TIME]

ya

no way those yami"s can turn 19's

most yami's are 17

that rich could be part of the pronblem

you want that thing to hit 6000 75% loaded fully trimmed up

 

[duconce]

Was reading these posts with interest, as I am switching to 4 blade props 14 5/8x17 REV 4's recommend by Ken. There is quite a bit of size difference in what has been tried here, guess will see how it works out. My boat [265] has f225s on it. Sounds like most of these test were over propped, so hoping these will be spot on.