I have a WHH Magnum 57 with a mid mod Zen. I have a worked over Prather 275 that has a poor hole shot, it cavitates from a stop and after a second or so bites and then pulls hard with good top end and good RPM. The other prop I have is a Prather 280 that has not been worked over. This prop has a great hole shot but no where near the same top end and the RPM's are down, a lot. I know this one needs worked and I don't think I up to that yet. I'm still working on set up as the boat is running wet and I'm taking it slowly. Advice on good props for me or what I can do with the one's I have are welcomed. I just a sport boater but I want the hole shot and the top end.

This got started on Wally's thread in the for sale section and I apologize for that.

Well first I would have to say that it is often hard to get the best of both worlds...a really good topend prop will most likely cavitate at start. This is more noticeable with a boat equipped with a clutch that allows you to come to a dead stop in the water. If you want the best top end speed you will most likely have to live with a little bit of cavitation at the start. Here is my opinion:

275: since it is giving you good RPM and topend and cavitating a bit at take off there probably isn't much you can do to the prop itself to make hole shot better. You could maybe try running it a little bit deeper... The drive angle should be 0 or close to it. (flat).

280: once you have ride attitude tweeked better you could probably get the 280 to work real well. I would setup properly with the 275 first though. Then if the 280 is still loading at top end you can try trimming the tips a little bit, reducing the overall diameter a little bit at a time. Test everytime you change it. Taking off 2-4 mm makes a HUGE difference so go slowly.

Make sure both props are well ballanced and ideally thinned and sharp to keep propwalk to a minimum. Boat will handle much better and be faster.

If you feel like spending a few bucks, get in touch with Voodoo Props or Propworks they both sell ready to run top quality props. Good luck! Keep us posted.

Thanks Marc, having been in to RC trucks in the past and dad was in to planes I can honestly say I love the boats. I'v been learning alot and the more I learn the more I want to know about how to make the boats run better. When you say run the Prop deeper do you mean bringing the out put shaft up from the keel toward the deck, I thought this would bring the bow up and run the boat looser, and that putting the shaft deeper in the water would bring the bow down making the boat run wet but more stable.

I also have trim tab but have not messed with those yet. I'v only had the boat out three times on a small pond but have gained enought trust in the boat I'm going to put it in the river next time.

Doug sorry about that, your are correct, my mistake... I corrected my post...

You could still try running the 275 deeper though and make sure the drive is at 0deg and tabs also. See what that does and take it from there.. a tiny bit of positive angle (prop end up) on the drive is acceptable on some boats to loosen the nose but shouldn't be more than 2-3 degrees in most cases. Rounding and cupping the tips of the prop slightly can also help reduce some lift, bringing the nose up.

Hello, have a blackjack 55 stock z mtr 813 carb ngk ird plug what would be the best prop for overall perf an top end has a 270 brass i polished it dont have a balancer yet an brass or stainless ty ron