Prop... Too much?

[justrfb]

Hello All.
I need your opinions and help please... We just launched "Da Boat". 20' two toons, 75 Merc 4 stroke hanging off the back. I had a BlackMax 14" X 11" prop on last season. 2 adults, 10 gallons of fuel, we ran 6,200 RPM @ 21.5 MPH. This year, today, 14" X 13" Cupped new prop, 2 adults, 25 gallons of fuel, we ran 5,350 RPM@ 21.7 MPH. Suggested RPM for our motor from Mercury is 5,000- 6,000 RPM. Is it too much prop? Should I go to an 14" X 11" Cupped prop? I am not sure they will take the one I have back. I would hate to have to buy a new one out right... What are your thoughts and suggestions?

I am so happy to get it in with a successful and uneventful, fun maiden 2015 launch.

[Bryden24shp]

Hey Buddy, hows it going? Glad to hear you got wet!
Are you running the last of the fuel from last season yet? Or was this run on fresh gas? Was the water temp real cold where the t-stats were cycling? That will change the fuel mapping considerably. I would run it a few more times just to see if it comes out of it. if not, then I would look at going back to the 11 pitch...
Let us know what happens.

[justrfb]

Thanks for the reply...

I filled up the boat with about 22 gallons as we were going to the marina to launch. There was a few treated gallons left from last season. I emailed the place I bought the prop from and they say no exchanges. So I am stuck... Is anyone interested in a brand new (used once) 100% satisfaction guaranteed, BlackMax 14 X 13 cupped for any reasonable offer? I am thinking it would be perfect for a 90 Merc 4 stroke or anything in that range that can use it. You would be helping me out, then I can get the BlackMax 14 x 11 cupped. Please let me know... I know this is too much prop. The motor was running perfect, the lake was still as glass and we always sail with at least 4 or 5 adults on the boat. Thanks for any help or suggestions...

Sincerely,
Rich

[justrfb]

Hello All.
Just ordered the BlackMax 14 X 11 Cupped prop... My wife is not happy about it but she loves me . Thank you Jesus! I hope this one will get the numbers where they need to be...

Sincerely,
Rich

[Bryden24shp]

I would toss the other in the back for spare. Even though its off, it could be used if you crash the new one. Or, you could always toss it on Ebay. It'll sell...
Glad you and the wife are ok! I know how that goes...

[teecro]

I'm watcing these propping threads very closely as I'm just not satisfied with the top speed in my pontoon; I realize that it's not a speed boat but right now the best I'm seeing is 17 MPH @ WOT of 5,200 RPM with the stock alum 3 bladed prop with 14" x 11 pitch. I just cleaned the toons so growth is not holding me back. The prop is a little beat up from an encounter with rock but nothing really bad.... I just purchased a 14" x 10 pitch with extra cup that I'll try when I get home mid June. BTW this is on an 18 foot Sun Tracker with a 60 HP Mercury Bigfoot....

[justrfb]

Hello.
I took delivery of our new 11" cupped prop, got the 13 " cupped off our boat and put the 11"cupped on... Perfect numbers... 5,900 RPM @ 21.4 MPH. !! I had the 13" cupped on my boat underway for about 15 minutes total. I have someone from the list who might be interested but if he isn't, you good people on this list have helped me so much, you have second dibs... ($100.00 plus shipping) The unopened Flo-Torq III from the 11" prop included. 100% satisfaction or send it back for your money back. If no one is interested, I will list it on Craigslist. THANK YOU for your help.

Sincerely,
Rich

[Bryden24shp]

Good Rich, I'm glad you got her running right! And your marriage is intact!