23/f-300

[SeaSick]

I am getting ready to repower my 1999 23cc with a 2012 Yami F300. If anyone has this combination can you tell me what prop has given you the best numbers and the height you have the motor mounted?

[shine]

that's going to be an awesome set-up

Check out the Yamaha performance bulletins and you can find a similar size boat with that motor. I was looking at upgrading to that motor for my boat after my F225 was stolen. Right now my (lightweight) 23CC has a F250 and I run a 19 pitch 4 blade Merc prop. With a 4 blade you can move the engine up a little.

My guess would be you could spin a 21 pitch no problem

I would recommend contacting Ken at prop gods

[Terry England]

A friend of mine just set the same boat up this summer. Replaced an F-250 with an F-300. He says be careful, they are geared differently and that you will be over-propped with the 21". With the 17", he "spools up" to 5900 WOT, making 45 knots and cruses at 4,000 making 25 knots and attaining 2.3 MPG.

[SeaSick]

Thanks for the input guys. I was hoping to spin a 19 pitch 4 blade with cavitation plate at 1 1/2" or more up from bottom but may not be able to do that. 2.3 mpg is less than I was wishing for but is a lot better than the twin 150 carbed Mercs are giving me now. Hoping to finish this project and get back to my '73 20 foot SF that is undergoing a down to the stringers resto. I am going to hang a carbed 150 Evinrude on it and not even worry about the fuel because I don't think it will get used much after I get the Yami on the 23.
I have a great running pair of '99 150 Mercs for sale if anyone is interested.
Bill

[Old'sCool]

Originally Posted by Terry England

A friend of mine just set the same boat up this summer. Replaced an F-250 with an F-300. He says be careful, they are geared differently and that you will be over-propped with the 21". With the 17", he "spools up" to 5900 WOT, making 45 knots and cruses at 4,000 making 25 knots and attaining 2.3 MPG.

Transom mount or bracket?

[Terry England]

It is Transom Mount. Kieth is a diver so he probably runs around with another 700# +/- more than a rod and reel fisherman. It probably effects his top end.

We make a lot of long runs on the west coast of Florida (look at the Continental Shelf on google earth) and easily log 100 mile days, so we tend to cruise more than those in the Keys and West Palm who are in 600' of water and can see the condos. They can mash the throttles down until the hit fiberglass beause they're going to be there in 17 minutes or 10 gallons. We just can't make the numbers work with a two Gag grouper per person limit here!

[joshmon71]

Ken@PropGods rocks.

4 blade all the way, get a stern lifting like Rev 4. Never go lower than the 17P on the Rev 4. I forgot why but Ken PropGod told me and that's all I needed to know.

My guess is start with the 17P Rev 4, considering your loads running.

My 23 is heavy. hatches and deck I used marine ply 1/2" and epoxy. when loaded for tuna its a lot of gear/ice/livewell if used. I think I run about 60-80 lbs ice, liferaft is 75?, and gear. Prob drops to 5800 under load WOT.

Engine is about 645 lbs as well. Armstrong Bracket.

I always try hit a near WOT usually on the inside of Pleasant Bay for a couple minutes to clean the engine out from trolling and idling, if not on the outside. You need to make sure you can get to near WOT with a 4S when propping, and run it there for a few minutes. No need to build carbon up .

Someone may chime in on other 4 blade props but once I tried a Rev 4 that was it. Much better offshore, and I did move my engine up 1 notch over the 3 blade 17P Mirage.

[kmoose]

I agree, the Rev 4 is one of my favorite props especially if you need stern lift. I ran a 23p on my 24 Formula (Fleetcraft) and it out performed a half a dozen other props I tried. Due to my lower gear ratio the 23p was the right pitch for me but when I moved my Suzuki to the Tsunami I was in need of bow lift and I had to go to a bigger 3 blade wheel (16" dia). I tried to go with a Bravo but just couldn't get the pitch I needed.

No matter what motor you are going with, Mercury props are the way to go and their hub formats can be adapdted to anything.

[kmoose]

Originally Posted by joshmon71

I always try hit a near WOT usually on the inside of Pleasant Bay for a couple minutes to clean the engine out from trolling and idling, if not on the outside. You need to make sure you can get to near WOT with a 4S when propping, and run it there for a few minutes. No need to build carbon up .

That's great advice for those just getting into 4 strokes. My engine idles all day long in between dive drops and I had a huge problem with carbon coking on my exaust valves and probably pistons too. My mechanic told me the same. Run it like you stole it for the last 5 or 6 miles at 90% and WOT for at least 2 minutes before you hit the ramp. This proceedure has keep my engine running way better for the last 1000 hours over the first 700. Also, very important not to over prop a 4 stroke. You sould see little to no rpm fluxuation in seas at any load.

[Reelsknotty]

keep us updated on this. I think this is the best combo, but would like some more real world experience.