Prop slection for 23' Mako inboard

[v12mac]

Anyone have a suggestion for a starting point? I am running a Mako 23’<br />Engine is Volvo Penta 3869162 5.0 G1-B ssn 4012067908<br />Trans is by Mercury Marine 5612458<br />Shaft is 1 1/8”<br /><br />We ran a 14”x15” Sunday and it really bogged down. The tach was acting up but best I could roughly figure is WOT we were in the low 3K range.<br /><br />Has anyone worked with this hull / motor set-up?<br /><br />Mac

 

[snapperbait]

Re: Prop slection for 23' Mako inboard

I'm close...<br /><br />I turn a 13x13 four blade OJ tournament ski boat prop on a 21' with a 5.0 and a 1:1 ratio direct drive.. Very happy with it.. <br /><br /> The four blade has very good balance and it bites very well.. Four blades may slightly decrease your top end speed, but they make up for that at cruise speed... <br /><br />Others you might look at would be 14" dia 12" pitch... <br /><br />When you get it right, and if the motors healthy and tuned, you should be able to spin the motor to 4400-4500rpm WOT...<br /><br />Price wise, a 13x13, three or four blade, would be least expensive and easiest to obtain...

 

[v12mac]

Re: Prop slection for 23' Mako inboard

Sounds like the right idea, this is not a fast boat nor do we want it to be. We are looking for a healthy cruse speed and fuel economy. <br /><br />I'll start looking for a 13x13 and a reliable tach.<br /><br />Mac

 

[salty87]

Re: Prop slection for 23' Mako inboard

acme marine has some really sweet inboard props. their 3 blade has the surface area of a 4 blade giving you a great hole shot with the top end of a 3 blade.<br /><br />they aren't too cheap though. i really like mine, i'll get another no doubt when it's time again.

 

[KaGee]

Re: Prop slection for 23' Mako inboard

Go Here For good info on selecting the proper prop.<br /><br />PS.... The prop dude at Iboats is good too.

 

[v12mac]

Re: Prop slection for 23' Mako inboard

Thanks for the info! I'll post back what works best.<br />Mac

 

[v12mac]

Re: Prop slection for 23' Mako inboard

I picked up a 13x13 3 blade 1 1/8 and it didn't fit! After lots of choice words we figured that the previous owner had taken a 1 1/8 and opened it up to 1 1/4 and didn't mention it or mark the prop. So very nervously we gave the go ahead to bore it out. Luckly it worked. Wow the fun of trying to figure what the heck people were doing when they rigged up a boat! <br /><br />Runs realy smooth good punch out of the hole but we are only around 3900-4000 range. <br /><br />I am debating taking some pitch out of this prop vs looking for a 14x12 <br /><br />Ideas?<br /><br />Mac

 

[snapperbait]

Re: Prop slection for 23' Mako inboard

Before you do anything, I'd suggest, if you have'nt done so already, make sure your engine is running up to par..<br /><br />If all's good in the engine department, have the shop take an inch of pitch out.. If the prop is cupped, which many are, that will be a factor as well.. With a cupped prop of equil pitch & diameter, you'll see a decrease in rpm by roughly 200 to 400 rpm..<br /><br />IMHO, I think a 14x12 would give you near the same results as the 13x13 is now..<br /><br />Talk to the guys at your prop shop.. Tell em' what rpm you're currently turning at WOT and tell em' what rpm you should be turning at WOT.. I'll bet they can get it just right for you..

 

[v12mac]

Re: Prop slection for 23' Mako inboard

Well looks like we are off to the prop shop. My brother whacked the brand new 13x13 on a speed bump of all things! I think the trailer is going to need attention too. (taller bunks) We are still a bit shy of 4K so we are going to take an inch of pitch out.<br />Mac

 

[snapperbait]

Re: Prop slection for 23' Mako inboard

oh no!..... %*@#'& speed bumps..