Prop choice

[Mickdund]

I have a 19' Kona w/1976 150 merc. inline 6.I run a 3 blade aluminum 13 1/4 x 17,it runs full throttle 5800 rpms@38 mph,trimmmed out it runs 43,what kind of prop could i use to get up around 50,or what other set-up could I use to get the speed I want.Thanx in advance I posted the thread about a month ago,since then I have better info on the boats performance.

[vector mike]

When you go from an aluminum prop to a stainless one you should drop down 2 inches in pitch. As far as getting more speed you need to get more HP. If your running at your peak rpm now,and put on a bigger prop, all you will do is bring the rpm down to an unsafe rpm unless you have the power to spin it up where it needs to be. You can lift the motor up to get less drag on the lower unit but not so far as to loose water pressure unless equiped with a low water pickup. You can also check your hull to make sure you have no "rockers or valleys" in the bottom and remove the hook if it has one. There are lots of ways to get more speed but it isn't easy or cheep.

[Mickdund]

If i where to install a jack plate,how much on the set back would be good.I changed my prop to a 13x19 gain another 5 mph.

[vector mike]

I'm not familar with that boat. How much does it weigh? Does it have a pad? Do you have a low water pickup? The more set back you have the higher you can lift the motor. If you get too much set back you can run into handling problems and if not enough you won't get enough bow lift unless your prop can pick it up.

[Mickdund]

Mike, I have 2 pics of the boat so you can get idea of what a Kona looks like,I'll send them via e-mail. I have no low water pick-ups,I not really sure what the term pad means,and I think the boat weight is around 1500

[vector mike]

I don't know if you sent me the pictures or not because I'm at home now but I will try and answer some of your questions as best I can.

FIRST: You can't pick up your motor very far because your water pickup is up on the sides of the lower unit. There is a way to cheat a little bit though. You can plug the top two holes on both sides so it won't suck air when you lift it up. Tap and plug the holes with short set screws but make sure to lock tite them in.

SECOND: The term pad refers to the bottom center of your boat. Does it have a flat pad or is it a V?

THIRD: Is that weight just the boat or is it with the motor? That motor weighs about 325 lbs.

The weight of your boat is a little on the heavy side so it could do with atleast 6" of set back and possibly more depending on how much weight you carry and if it is a bowrider or not. The more set back that you have the farther you can lift your motor because you are getting "cleaner water". I hope I have helped you some on your quest for more speed. I'll check my e-mail tomorrow when I get to work to see if you sent the pictures. If I can help you any more just let me know. There are alot more people on this board more experienced than I am so hopefully they can give their opinions too.:)

[Mickdund]

Thanx Mike for all the advice,I haven't sent the pics yet,I will tomorrow,as far as the weight I'm guessing,the next time I have it in the water,I going to weigh the trailer w/o the boat and go from there, to get a accurate weight, before I start spending any money on jack plates.The pad on the boat has a slight V.Thanx again--John
Mike I found a boat that is identical to my,except for the inboard.heres the linkhttp://adcache.boattraderonline.com/6/2/4/30254724.htm

[airide18]

Run a chopper.