What prop to buy? (Edit)

[rjherrman_1]

Hello all,<br /><br />I purchased my boat used and the previous owner smoked the original prop. He replaced it with a 48-78120-A40 19P. I have soon come to realize that this is NOT the correct prop for this boat. The original prop was 48-832830-C1 19P. <br /><br />I currently have a 96' Mariah 21.5 Cuddy with the 350 Merc/ Alpha Gen 2 drive. WOT RPM's are at roughly 4600 so I am good there. <br /><br />The issue is that I can not get out of the hole with more than two people on board unless then get up in the cuddy (lame). I also can not pull a tuber or a skier as it can not get them out of the water. Also, whenever I trim the motor up it porpouses so badly, and I have to run it with the drive all the way down..(lame again).I pulled my hair out trying to figure this thing out. I even brought it into the shop and the motor and drive are perfect.. so.. I can only assume it's the prop.. <br /><br />My manual doesn't say anything about what the proper prop is for this application, so I am going in this blind. I do know that I am really looking for ballistic holeshots and I could really care less if I loose a mph or two on the top end since we have speed limits of 40MPH here anyway. Am I correct in my thoughts of migrating over to the 5-Blade props? I've read most of the previous topics on the High Five and Ron Hill's props, and certainly the Hill's prop is priced quite a bit better. <br /><br />I guess I am just trying to figure out what I need so I can enjoy the season this year instead of burning through a ton of gas trying to get up on plane completely void of watersport activities..<br /><br />Thanks!<br /><br />Ryan

 

[Silvertip]

Re: What prop to buy? (Edit)

Changing the number of blades and staying with the same pitch will probably not solve your problem. Perhaps someone will come along who owns the identical boat and can offer a "known" solution. That said, cruising and water sports generally fall on both ends of the performance spectrum. If you do lots of water sports, you need hole shot. If you do lots of cruising you need a prop for cruising. Anyting in between is a compromise. So -- my suggestion would be to try a 17 pitch prop, or an 18P stainless. 18 would be a compromise for all around use. 17 would get you out of the hole and work for water sports. Since your boat is very stern heavy, you might also consider one the most inexpensive and most effective performance enhancements for stern heavy boats and that Smart Tabs. These are trim tabs that provide stern lift. They allow much better hole shot and allow you to stay on plane at slower speeds. They are available right here in iBoats. Trade name is "Smart Tabs". In fact you may not even need a prop change since the 19 seems about right for WOT.

 

[rjherrman_1]

Re: What prop to buy? (Edit)

My previous boat was a 1984 Century 4000 cuddy with the same drive setup. That was a heavy boat!<br /><br />I ran a 19P Quicksilver SS 3-blade and it ripped out of the hole. Performance was perfect. I expect the same or better performance out of this boat since it is much lighter and has a better hull design.<br /><br />I can only assume that the prop on there now has the wrong rake and cupping.

 

[studlymandingo]

Re: What prop to buy? (Edit)

Have you done anything to change the setup yet? Keep the forum posted with your trials, and discoveries.

 

[walleyehed]

Re: What prop to buy? (Edit)

I expect the same or better performance out of this boat since it is much lighter and has a better hull design.<br />

Changing all of those variables changes the end result...the Quicksilver may have been well suited to the other boat, but that prop is not huge on performance.<br />Total weight means less than how that weight is actually distributed.<br />I can look those Merc prop #'s up, but they mean nothing and are only a reference for what "may" be a better prop.<br />A 5-bld in my opinion will likely "hide" the real problem.<br />The best solution for your application, may be a set of smart-tabs..I've run with and without, and I'll never have any boat again without them.<br />The porpoising, I think, is an out of balance situation, and if you had the correct prop for whatever use you want, it will still porpoise except at WOT, I'd bet. It also sounds as though you may need a prop with more stern-lift, and a 4-bld may fix some of that if the right prop is used.<br />I'll run those props down just to see what they are and see if maybe it is way off.<br />I would also prop that for 5000RPM if it were me..we run our 5.7 clear up to 6000 with the prop that suits what we want to do. 4600 ain't high enough for a load.