Mercury High Five

(weskel) · (weskel) **Join Date: Jan 2007** 06-25-2009, 1:10 PM

Question for ya,

I just bought a high five and have not had the boat in the water yet, but I noticed at the base of each blade on the hub there are holes about 3/4 inch diameter.

I didnt think to much about it until I saw another boat yesterday with the same prop and all the holes on his had plugs in them...

Whats the story....

(smuurph84) · (smuurph84) **Join Date: Oct 2008** 06-25-2009, 1:42 PM

I have a hive five the holes allow you to adjust the prop a little bit. they make different size plugs to put in those holes, some are solid some are 1/4" open some are 1/2" open I believe.Im not really sure how it works but I found that using the largest holes gave me the best hole shot and using the solid plugs gave me a higher top speed very little mind you maybe 2mph? I ended up pulling two plugs out completely to give me the best hole shot. when I went to three it felt like the prop was slipping on takeoff. you will love the prop! its not an inboard hole shot but it was a big difference from the stock prop oh yeah the little plugs sink so if you are doing your adjusting out on the lake be careful.

(rallyart) · (rallyart) **Join Date: Nov 2006** 06-25-2009, 1:57 PM

The holes vent exhaust at the blades and let them cavitate in a controlled manner. The bigger the hole the bigger the effect. As your boat picks up speed the water traveling past the prop makes it easier for gas to exit behind and harder for gas to exit through the holes.
You 'tune' the start by adjusting the hole size. There should be plugs with all new props. You can get different plugs or just drill the closed plugs. More gas coming out lets the prop slip and keeps RPM higher on starts for a faster start. If you bog a bit on the start you make the hole bigger.
It works.

(weskel) · (weskel) **Join Date: Jan 2007** 06-25-2009, 3:38 PM

Thanks for the info, but I have no plugs in any of them. How will this affect my performance until I can get some to experiment with?

(rallyart) · (rallyart) **Join Date: Nov 2006** 06-25-2009, 5:19 PM

Like Murph said. Prop spins more on start and the top speed will be down just a bit. Mileage might be slightly less at wake speeds.

When you have them you should make sure they all have the same size holes.

(Message edited by rallyart on June 25, 2009)

(weskel) · (weskel) **Join Date: Jan 2007** 06-25-2009, 5:55 PM

But I will be OK without any plugs in?

(rallyart) · (rallyart) **Join Date: Nov 2006** 06-25-2009, 7:15 PM

Yup. Just better after you get some, maybe.

(smuurph84) · (smuurph84) **Join Date: Oct 2008** 06-29-2009, 9:46 AM

kelly I wasn't i pulled all of my plugs out at first hoping to get a great hole shot, and my boat wouldn't hardly get up on plan. I had to pull over and put them in. make sure you take some they are very cheap I got mine at my local repair shop.

(smuurph84) · (smuurph84) **Join Date: Oct 2008** 06-29-2009, 9:48 AM

it my be diffrent on your boat mine is a 5.0 mpi with the alpha one drive.

(weskel) · (weskel) **Join Date: Jan 2007** 06-29-2009, 10:26 AM

Sounds like we have almost the same engine except mine is not injected,

Did you fill all the holes with solid ones?