# Faster Holeshot by Venting my Prop



## Dillusion

I was wondering this too lately, I almost did it- but decided to not mess anything up when not necessary. After having my 10x15 stainless cupped all the way down the edge of the blade my holeshot is fine and my top end didn't suffer more than 1mph loss from the cup.

Technically you don't need to change anything inside the motor...the venting is just inducing a 'controlled by hole size' slip of the prop while in the hole and removal of said 'slip' when going forward because the exhaust gasses just channel out of the prop hub and midsection exhaust relief.


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## paint it black

My Raker came with the vents on it. I know Ryan got his vented, and said it made a difference.


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## Guest

> I was wondering this too lately, I almost did it- but decided to not mess anything up when not necessary. After having my 10x15 stainless cupped all the way down the edge of the blade my holeshot is fine and my top end didn't suffer more than 1mph loss from the cup.
> 
> Technically you don't need to change anything inside the motor...the venting is just inducing a 'controlled by hole size' slip of the prop while in the hole and removal of said 'slip' when going forward because the exhaust gasses just channel out of the prop hub and midsection exhaust relief.


Right,
If I don't notice improvement then it gives a list to check at the motor.


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## cutrunner

Prop venting like previously mentioned is mainly for at least 50hp and up. The smaller motors (unless on a light little hydro or thin aluminum jon boat) just dont have any real torque. The small hole you drilled may help, but dont go much bigger or it will hurt it


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## High + Dry Adventures

I would recommend having it professionally done for the best performance.  You cant just drill the holes anywhere.






> One more little tweak.
> 
> I have my prop dialed in at:
> WOT
> RPM
> No blowout
> 
> but wanted to increase hole shot without loosing top end. Did a little research and Noticed the viper had vent holes. I went to frank and jimmies and had mine modified.  They did a great job and prop is well balanced.
> 
> www.fjprop.com
> 
> 1 hole for each blade


Yep here it is! 

You need to stopwatch your time to plane and see if it decreased.

In theory... it has to do with the pressure inside the prop and the pressure on the outside of the prop.  The disrupted water caused by exhaust air bubbles allows the prop to spool up faster.  When the pressures equal the prop works the same as it did before.  That why u dont lose top end!

 



> Pretty simple, but stayed conservative and drilled three small 7/32" holes near the base of each blade. Hopefully it works without any Motor timing, carb adj, throttle linkage adjustments etc.....


Why you would gamble on drilling to risk having to do these adjustments is just asinine.  Anyone looking to do this, take it to a prop shop.  Thats what they do. The holes will be in the exact spot on every blade.  That will = performance. When it comes to safety and performance there is no "Hopefully"


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## Sheremeta

I'm having Ken at prop Gods repitch and vent my 15p powertech to improve hole shot.


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## Guest

> I'm having Ken at prop Gods repitch and vent my 15p powertech to improve hole shot.


Ken put up a diagram on another forum as a DIY. The holes did improve Hole Shot, but have yet to install my Tabs. Will talk with Ken in the next few days on another Prop.

With my PT SRA3 12 pitch I'm doing 28.5mph solo, but would love to get over 30mph without sacrificing anything.


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## Guest

Maybe just take the 1999 50hp Tohatsu S.S. I bought last year up to the Shop and replace it with my Mercury 25hp 2 stroke. :

The 50hp does add about 45lbs. to my transom, but would also be running right around 42mph-44mph.


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## cutrunner

Lets race


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## Guest

> Lets race


How about Binimi this summer?


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## cutrunner

Sounds good


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## Creek Runner

Can I join in please?


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## cutrunner

We would let you in if you wouldnt of sold the bullet..


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## Creek Runner

> We would let you in if you wouldnt of sold the bullet..


You mean I can't bring the STV I will even run the small prop! LOL!  ;D


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## cutrunner

You can bring it, just put a counter rotation prop on it and put it into reverse to move forward. Thats fair enough eh?


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## Sheremeta

> I'm having Ken at prop Gods repitch and vent my 15p powertech to improve hole shot.
> 
> 
> 
> Ken put up a diagram on another forum as a DIY. The holes did improve Hole Shot, but have yet to install my Tabs. Will talk with Ken in the next few days on another Prop.
> 
> With my PT SRA3 12 pitch I'm doing 28.5mph solo, but would love to get over 30mph without sacrificing anything.
Click to expand...


If you went to a 13 or 14p of the same model prop you may achieve that goal. What did Ken say? I'm extremely impressed with his knowledge and service.


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## Guest

Len said that the Power Tech SRA3 props are about the fastest he has come across. Drop the pitch to 11 maybe 10 and add just a little cup to the tips to gain speed.

I need to buy a Tach again, but I'm not sending another $50 to Tiny Tach. I have gone through a ton of them over the years and have 2 that read all kinds of crazy ****. They might as well be the $6 Tachs from China on EBay.

Analog?Sendec?


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## JBMitziSkiff

I run a vented Powertech prop RXB4 I believe it is a 13pitch but need to look again. 
It will rip your head off coming out of the hole on my 40 Etec. Runs 32 with just me on a good day. 2 people runs 29-30.


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## byrdseye

For what it's worth, I drilled out the vent holes on my 19p Viper to try and get a better holeshot with the 60 E-Tec and it really did make a difference. I'm at 7/16ths now and thinking about going to 1/2". 
Also, I have a 19p Rogue that I think I'll send to Frank & Jimmies for vent holes .......my little motor has a hard time spinning it up when my large friends are on board.


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## sickz284u

> For what it's worth, I drilled out the vent holes on my 19p Viper to try and get a better holeshot with the 60 E-Tec and it really did make a difference. I'm at 7/16ths now and thinking about going to 1/2".
> Also, I have a 19p Rogue that I think I'll send to Frank & Jimmies for vent holes .......my little motor has a hard time spinning it up when my large friends are on board.


19P is a lot for that motor. I run a 60 etec and run a 4 blade 15P with cupping.


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## High + Dry Adventures

> For what it's worth, I drilled out the vent holes on my 19p Viper to try and get a better holeshot with the 60 E-Tec and it really did make a difference. I'm at 7/16ths now and thinking about going to 1/2".
> Also, I have a 19p Rogue that I think I'll send to Frank & Jimmies for vent holes .......my little motor has a hard time spinning it up when my large friends are on board.
> 
> 
> 
> 19P is a lot for that motor. I run a 60 etec and run a 4 blade 15P with cupping.
Click to expand...

To determine what "a lot" is depends on the weight of the skiff and it's passengers.

I'm running the 19 and it has good hole shot with two anglers in the back, handles excellent in the turns and a great top end.


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## sickz284u

> For what it's worth, I drilled out the vent holes on my 19p Viper to try and get a better holeshot with the 60 E-Tec and it really did make a difference. I'm at 7/16ths now and thinking about going to 1/2".
> Also, I have a 19p Rogue that I think I'll send to Frank & Jimmies for vent holes .......my little motor has a hard time spinning it up when my large friends are on board.
> 
> 
> 
> 19P is a lot for that motor. I run a 60 etec and run a 4 blade 15P with cupping.
> 
> Click to expand...
> 
> To determine what "a lot" is depends on the weight of the skiff and it's passengers.
> 
> I'm running the 19 and it has good hole shot with two anglers in the back, handles excellent in the turns and a great top end.
Click to expand...

I guess that was a bad choice of wording on my part. I was basing this on what my personal expectations were for my skiff and the conditions I normally operate under. There are also a lot of different opinions on what good hole shot is. My skiff jumps on place in about a boat length. Maybe even slightly less. Also I should have asked him if he has ever timed his hole shot to see how long it takes to get on plane. I also like the ability to stay on plane at low speeds. I can keep the boat on plane at 10-11mph without messing with the trim tabs at all. 

If I am not mistaken the Islamorada 18 also weighs a bit more then your copperhead. Love your skiff BTW it's gorgeous. Top speed isn't that important to me really. I see about 34-37 WOT with 2 guys and a full tank of fuel. That's plenty fast enough IMO. 

Anyway I just wanted to clarify that. I should have asked what his expectations were of the skiff. Maybe Krusty can provide more details on his skiff etc and we can make a batter call. 

Tight lines.


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## Qman

I run a vented turning point 17 on a 1756 tunnel g3 with Yamaha t60. The prop came vented but had hogan brothers near chief land fl do some extra custom venting on the back side of the blade also. Made a big difference in getting me up to near max rpm and nice hole shot out of a 3 blade prop.


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