dialing it in

[south599]

Hey guys I run a 1984 bullet 17vee with a 1985 Johnson 150 bob's nose cone. and a recent add of a hydrodynamics rapid jack magnum jack plate with 8" of setback. I currently have the motor 1 1/2 below pad. My problem comes in where the boat originally came with a 28 pitch omc raker my last numbers with it were 63 mph at 4500 rpms with 2 people and half tank of gas( I know terrible rpms hince the new jackplate). I recently got a 27 pitch srx chopper(supposedly with a bullet cut) at 1 1/2 below pad this prop has absolutely terrible holeshot!! But super fast when I eventually do get on plane and much smoother than the raker(can't drive it yet so I don't know the wot throttle numbers) I have talked to performance in soddy and they recommend a 25 trophy. however, I am not made out of money. wanted to know anyone else's experiences along these lines and maybe just have something set up wrong and can actually run what I have now. I am looking for a good all around performance, I fish not race but I do like to put that upset look on those guys with the $45000 rigs when I can stay with them!! emoBigsmile thanks ahead of time for any help

 

[Oldman]

call and talk to billy eaves one of the best prop men any where.he will work with you until it is right.423-667-2160 or 423-531-2569

 

[south599]

what are his business hours?

 

[Oldman]

he gets there about 9.one of those is his cell.

 

[Liveliner]

Sounds like you have too much exhaust gas/air in front of your blades at Hole-shot and getting a lot of slipping. That is if you feel it over revving. A Raker is designed to bite better setting high. and run at top end even partially out of the water. The 28 pitch is also getting a better bite at take-off.. The 27 Chopper is more a high speed prop and should turn faster cutting the water cleaner at top end.. Because of two possible factors you are having hole shot issues.. First check the opening size of the exhaust port holes in front of each blade. If they are unplugged or have large size openings that will cause your prop to slip or free-spin sitting still and at slow speed during takeoff. To fix that Add plastic insert plugs with no opening or no more than a 1/4" hole diameter in that 27. The other and second most obvious problem is that your hull design and jack plate allows for a good arch where most any prop will bite well at high speed... However Props differ and all will not bite without sucking air at Takeoff if set too high.. Do the holes first. If you feel the holes in your prop are in fact small then you will have to start dropping your engine down until you get results at takeoff... Dropping the engine should not start effecting your top end for the amount you need. (I assume you understand the purpose of the exhaust port holes in the prop.) Good luck.. This is part one... The final tune will be WOT/Peak Speed/ Balanced Steering. Know your engine max RPM and do not exceed that testing any prop...

 

[south599]

yes the raker already has 1/4 holes that I will probably open up because it bogs down the motor sometimes, but very glad to hear they are good props to run this high I have been nervous about that. the srx chopper is not a through hub exhaust prop and therefore has no holes. Billy recommended that the answer for that prop was to raise the motor more and then we would start working the prop to get it to fit my set up just right. and also lucky for me the johnsons stock like my motor have rev limiters so I cant exceed the recommended wot range either way. ill let you all know how the change goes this weekend. im going to force myself to go to the lake to just test props and working on my driving ability.....that's going to be a hard battle. thanks for the info!

 

[south599]

Also on my raker prop the person before me put the 1/4 holes in. he filled the original exhaust holes then drilled the 1/4 within the original hole. does it matter that those 1/4 holes are not matched to each other?

 

[Oldman]

Ben ask billy he can answer all your questions about props.

 

[Liveliner]

<div>
</div>

south599 - 6/12/2013 7:47 AM Also on my raker prop the person before me put the 1/4 holes in. he filled the original exhaust holes then drilled the 1/4 within the original hole. does it matter that those 1/4 holes are not matched to each other?

</p>

"NO" After you get out of the hole, they serve absolutely no purpose. </p>

The open Exhaust over your Chopper Prop still makes me feel you are having issues with your prop free spinning in air. As you learn to drive.. do this >>> At take-off. Do not just stand in your throttle. Do one or two hard throttle pumps letting off and then feather your throttle at the maximum breaking point to blast out of the hole. The pumps breaks up the exhaust air pocket and your prop will Bite into solid water. When you get the feel of controlling your Prop spin you will Love it...</p>

Let us know</p>

 

[south599]

Pulled my motor up to 1/4 in. Below the pad. The skid plate helped my setup a lot the prop will do great with a little bit of work i think. I pushed to 67 mph @5500 rpm. Probably could have made it to 68-69 before my rev. Limiter. A little work im hoping at least low 70's. Still holding 30psi as well.

 

[south599]

Pulled my motor up to 1/4 in. Below the pad. The skid plate helped my setup a lot the prop will do great with a little bit of work i think. I pushed to 67 mph @5500 rpm. Probably could have made it to 68-69 before my rev. Limiter. A little work im hoping at least low 70's. Still holding 30psi as well.

 

[south599]

just wanted to let you guys know Billy is terrific. I took my props down to him yesterday and he straightened and shaped them both to what he thought would work for my boat and did it for FREE!!! I will be taking all of my propeller stuff to him from now on...plus he let me watch and I love to learn things like that, but it hurt watching him take a hammer to those blades.

 

[Oldman]

i told you billy is the man.

 

[south599]

alright guys took my 28p raker prop that billy cleaned up for me out on Saturday in the 58 tournament. It Grabs a lot better than that chopper initially out of the hole but then right when im about on pad the prop comes out of the water and spins like crazy. I think im goin to try moving my jackplate down 1/2in. its at 1/4 below pad. also thinking that that chopper would do wonders with a little cupping in the back ill have to talk to billy about that. Never maxed out the raker because Im still nervous about my motor and spinning these props like this just to get on plane hurts me a little, but that old Johnson has held up super well. as far as numbers I was doing around 65 at around 5000-5200 rpms. I think lowering that jackplate will reduce that prop spin a lot without effecting the wot rpms too much

 

[Liveliner]

<div>That is what I said above... Drop your engine lower.. Your prop is sucking air from the surface.. I also said the Raker will run better shallow. I bet that if you drop down an Inch you will see a huge difference.. Maybe more than an inch ... No kidding...</div>

From above >>> "<span style="background-color: #ececec"><font color="#43647e" face="Verdana, Arial, sans-serif" size="2">However Props differ and all will not bite without sucking air at Takeoff if set too high.. Do the holes first. If you feel the holes in your prop are in fact small then you will have to start dropping your engine down until you get results at takeoff... Dropping the engine should not start effecting your top end for the amount you need."</font></span></p>

<span style="background-color: #ececec"><font color="#43647e" face="Verdana, Arial, sans-serif" size="2">If you start setting your engine too low you may start to detect some minorPorpoisingjust before it sets on plane. That will tell you your lower limit.</font></span></p>

</p>

 

[south599]

Tonight I had the motor at 3/4 in. below pad with the raker and at billy's suggestion I plugged 2 of the 3 holes. The holeshot was much better with it only reving to 5000 and catching quickly after that. But my wot numbers went to low again because of the bobs nose cone, which is why its so high in the first place. Gonna meet Billy thursday and try a 26 trophy for a fishing prop and work that srx chopper a little more. Im fairly sure that raker is about to go up for sale, because when I put it in position to work well it starts to get boggy and cant turn high enough rpms. ill update you all after some more testing.