Splash day

[McGillicuddy]

Congrats Chance!
Looks like you got your extension figured out. That Bigshrimpin fellow is pretty bright, huh?

What prop are you running now?

Are you coming in a bit under the desired max rpms at WOT.
If so, I think the 15p black max prop would help you some on the hole shot and get the stern up. She looks look pretty balanced though.

I'm running a 115 inline 6 and getting 36mph at 5600rpm on a Seafari with said prop. If you want stainless, Powertech Makes the MQF3 series. Same design. Moderate rake low cup easy-to-turn big blades. Did wonders for my motor and overall performance. I believe the stilletto is very similar and has a bit of a following, too. Just not sure if the 115 turns it as easily.

Hope you find the solution. I concur, 28mph is not satisfactory on a 20 w/ a 115.

p.s. is the green stuff on the hull, botanical growth, or just paint? Just a ? of friction.

[CHANCE1234]

Thanks, this probably has something to do with part of my numbers


This picture is of the only numbers on the prop. The 17P is self explanatory, but I don't know the diameter or what the rest of these numbers mean


What diameter was your 15p you were running? The bottom is a combo of some minimal growth and a few layers of old bottom paint. I didn't touch the hull, ran out of money.

That bigshrimpin guys is pretty bright. I'm not sure exactly what I got for RPMs I'll have to pay attention to that next time. I was only out for about 15 minutes today during the only rain shower of the day.

I don't really know if I care about whole shot more than getting more cruising speed. So it sounds like a 3 blade 15 pitch, but what diameter? 13?? Thanks for they help guys

[FishStretcher]

I run a 13" diameter 15" pitch Solas Amita4 aluminum prop. $110 from boats.net. I started with the 17" pitch version which is 12-3/4" diameter. Same splines and hub diameter as your Merc, I bet.

There is a stainless 16" pitch Yamaha 4 blade that should fit- but it is probably near $300 used, and $450 new? And there re probably many others.

The local prop shop doesn't like the Solas props- (I think) there is no profit margin. I like it for that reason.

The prop manufacturer I worked with at my last job (ACME- they make fully CNC machined bronze inboard props) said it is easier for a prop shop to take cup out of a prop accurately than put it in. I am not sure if that applies to small outboard props.

http://www.classicseacraft.com/commu...ad.php?t=24872

I condensed my prop experience in the thread above.

I have photobucket pics here of my prop and hydroshield. The motor was a hole or two too low- I raised it after these pics were taken. The flying wing helps lift the extra 150 lb on the transom. Along with an under console fuel tank and battery setup.

http://s1119.photobucket.com/user/Fi...tml?sort=3&o=0

Originally Posted by CHANCE1234

Thanks, this probably has something to do with part of my numbers<snip>
What diameter was your 15p you were running? The bottom is a combo of some minimal growth and a few layers of old bottom paint. I didn't touch the hull, ran out of money.

That bigshrimpin guys is pretty bright. I'm not sure exactly what I got for RPMs I'll have to pay attention to that next time. I was only out for about 15 minutes today during the only rain shower of the day.

I don't really know if I care about whole shot more than getting more cruising speed. So it sounds like a 3 blade 15 pitch, but what diameter? 13?? Thanks for they help guys

[McGillicuddy]

Originally Posted by CHANCE1234

Thanks, this probably has something to do with part of my numbers

This picture is of the only numbers on the prop. The 17P is self explanatory, but I don't know the diameter or what the rest of these numbers mean



I don't really know if I care about whole shot more than getting more cruising speed. So it sounds like a 3 blade 15 pitch, but what diameter? 13?? Thanks for they help guys

Yeah, that prop is the right one but the wrong shape - it should have more curves... You have the Mercury Black Max there.

The 15p has a 13-3/4" diameter. Quicksilver model is called Black Diamond, QA2034X is 15p model no. 17p has 13-1/4" diameter, model no. is QA2036X. Should be same sizes for Mercury Black Max.

You will do much better with a new prop. Any shop should have this prop used, in good shape. Try them both pitches with a "heavy" load. If regularly run with 3 people, I'd stick w/ the 15 pitch.

When you run them monitor your rpms. You should be able to achieve the maximum targeted rpms for your motor at WOT.

Good luck! Keep us posted on your performance results.

[Bushwacker]

Originally Posted by CHANCE1234

. . . I don't really know if I care about whole shot more than getting more cruising speed. So it sounds like a 3 blade 15 pitch, but what diameter? 13?? Thanks for they help guys

Chance,

I also ran a 13 3/4 dia. X 15P OMC SST prop when I had a 115 V-4 on my Seafari. That was a 1975 vintage motor when they were rated at the powerhead, so it was probably only about 100 hp at the prop. It used to turn 5500 rpm and I could run 32-34 anytime with a very heavy load, maybe 35 with a light load. Hole shot was great and it would plane at 12 mph. You'll get the best performance and durability if you prop the motor so it turns max rated rpm with the load you normally carry.

On motor height, you should be able to clearly see the AV plate when on plane, so it should be at least an inch above the bottom of hull.
Denny