keeping the prop hooked up

[anthony_marquart]

When the v937 I have trouble keeping the prop hooked up.

What do you guys suggest I try?

 

[Speed Jr.]

When does it fall off? Corners or slowing down too much? Does it slip when launching the boat? Lowering strut makes sense, but it may not push the prop then......

Larry

 

[nitro_nemesis]

Larry, from what I saw when I was w/ tony today - if you have the boat full throttle @ take off it hesitates/cavs some then makes it on plane and hooks up really good, but if he even backs off the throttle a little w/ that prop it bogs right back down and chokes !!!

 

[Dan_Cousin]

Sounds like too much prop or too short of a pipe. How far is th strut below the rear sponsons?

you might try raising the strut.

 

[Speed Jr.]

So what do you mean by "hooked up"? does this mean the prop slips, or engine bogs like its overloading?

Me and Dan are talking about 2 different things.

Larry

 

[nitro_nemesis]

So what do you mean by "hooked up"? does this mean the prop slips, or engine bogs like its overloading?

Me and Dan are talking about 2 different things.

Larry

Well, for me - by saying hooks up I mean catches water and takes off. If you start talking slip to me i'm in the blue, still new @ this and don't know exactly what terms you guys use for everything yet :huh:

 

[Speed Jr.]

When someone is talking about prop not being "hooked up", to me that would infer that the prop is spinning at a higher RPM than the speed shows. Like its slipping in a sense. What I think you may be refering to is as we call "on the pipe" this is that barrier from running wet and slow not allowing the motor to turn RPM's to popping up on top of the water and going fast and getting those high rpm's. they are completely different things. If your not getting on the pipe, you can try a few things: 1. Raise the strut 2. Lengthen the pipe 3. Try a smaller prop 4. If its a outrigger, you may want to check the sponson bottoms and make sure your not running too much neg. which will cause excessive drag at launch. The first three are the likely changes, the 4th is if your completely off on the set up which your probably not. If the prop isnt "hooking up", then the strut is probably to high, but I have a feeling your what talking about what we refer to as "on the pipe"

Hope this helps, let me know if any of this rings a bell

Larry

 

[anthony_marquart]

Sorry about not being more clear. I am talking about "hooking up", not falling off the pipe. I launch the boat and the prop is cavatating and the engine at high rpm. THe prop slowly grabs and the boat takes off and planes. If I let up on the throttle or turn the prop cavatates again, RPMs go up, speed goes down and can't get back up on plane, eventually stalling the engine and I fish it out.

I'm guessing I need to raise the prop or maybe lower,... I don't know... I think the power to pull it is there cause I can get off the beach.. Just need to get the right setup to stay on plane with that prop...

 

[Speed Jr.]

Try lowering the strut. See what happens. This didnt happen with any of the other props??

Larry

 

[anthony_marquart]

The other props would either plane or not plane. It was a setup issue with those that I have now fixed. This is the only prop I'm having problems with right now. This one is unhooking after it hooks up for a while...

Try lowering the strut. See what happens. This didnt happen with any of the other props??

Larry

 

[Dan_Cousin]

The other props would either plane or not plane. It was a setup issue with those that I have now fixed. This is the only prop I'm having problems with right now. This one is unhooking after it hooks up for a while...

Try lowering the strut. See what happens. This didnt happen with any of the other props??

Larry

Heres a coule of thing to try.

Lower the prop into the water.

If the strut is already well below the rear sponsons you might try a test by putting some weight in the back of the boat to keep it down.

Take all negative out of the strut.

when the boat is cavitating try backing off the throttle a little to let the water get into the prop.

you might try launching at 1/2 to 3/4 throttle and see if it gets better.

if none of these work you probably don't have enough blade area.

On larger props I'll ususally cup the ears a bit for better bite but you don't have much blade the play with on a x637.

 

[Speed Jr.]

I think you bring up a good possibility Dan, This will happen if the center of gravity is too far forward, thats why adding weight to the rear may fix it. Have you balanced your boat Anthony? where is the COG as compared to the trailing edge of the front sponsons?

Larry

 

[Dan_Cousin]

I think you bring up a good possibility Dan, This will happen if the center of gravity is too far forward, thats why adding weight to the rear may fix it. Have you balanced your boat Anthony? where is the COG as compared to the trailing edge of the front sponsons?

Larry

thats right. My frist boat was really LIGHT for a 45 especially for that time (late 80s). The boat would always blow the back end out the water until Jeff Baham walked up and put a piece of cement in the bait box.

well lets just say my motors are further back now.

 

[nitro_nemesis]

We'll see if I get the same problem Tony does when I run my boat here soon when the weather breaks again. My Blizzard is almost exactly the same weight as tony's boat but a few inches shorter, and I'm pretty sure my COG is a tad bit farther back than his. Be interesting to see how different or similar the boats run and what props make them run better than others since the setups are somewhat similar, except I don't run rear sponsons. All info will be gladly shared B) as I'm hoping sometime soon we can get more of these .12 - 15's spraying around !!!!!

 

[AndyBrown]

That is the nature of the "V" series props. They cavitate easily when the hull drag is very high and the foward speed is low. Once the speed is up and the hull drag is low, that prop will hook up great and be very fast.

Eveything has to be just right on the boat set-up to use the V937/7.

I would suggest that you get your boat working well with a 1640 first, then go back and work with the V937/3.

 

[Don Templeton]

I agree with Andy,

The 1440 with some good cup is a very stable prop for a 12. However, with the V937 I would make some sponsons that give the Bantem a longer foot print to adjust the CG more to the back but you will also need to extend the turn fin. So design the sponsons more like an SG. :lol:

Don

 

[Don Templeton]

The above post is wrong. I ment to say 1640 with cup, not 1440. :blink: Matter of fact, it was made by Andy.

Don

 

[anthony_marquart]

I actually ran a Mark Sholund 1440 today. It's the one that many of the tunnel racers are using. It ran very well. What is the difference between a 1440 and a 1640? Would that be more pitch and more lift? This prop ran real well today. Actually I think it is now my best running prop. Should I get a 1640? I think the 1440 I'm running is pitched to 3.1, its also back cut. It did run well..

Don, do you have your riptide ready to run? It was perfect at the lake today. I need another sunny day like today and someone to take a few pics for the website. The last few times i was there a person I didn't recognize pulled up and talked to me. I was hoping it was you.

The above post is wrong. I ment to say 1640 with cup, not 1440. :blink: Matter of fact, it was made by Andy.

Don

 

[Don Templeton]

Anthony,

I have another 1640 Cuped from Mark that I have not tried yet. You are welcome to try it . Do you plan to be at the lake Sunday and if so what time? I could probably bring it in the morning but the little wife has plans for the afternoon. I think the cup takes a little of the lift out of the 1640.

Let me know,

839-3776 You can call me tonight. I'm usually up late.

Don

PS I could also bring it to your house in the morning if you're not running early.

 

[anthony_marquart]

Ihope to run tomorrow but I don't know when.. I'll call you in the morning

Anthony,

I have another 1640 Cuped from Mark that I have not tried yet. You are welcome to try it . Do you plan to be at the lake Sunday and if so what time? I could probably bring it in the morning but the little wife has plans for the afternoon. I think the cup takes a little of the lift out of the 1640.

Let me know,

839-3776 You can call me tonight. I'm usually up late.

Don

PS I could also bring it to your house in the morning if you're not running early.