Rinker 192 prop issues

Joined
Oct 14, 2008
Messages
9
Just bought a 2007 Rinker 192SE with Mercruiser 5.0MPI 260HP. It came with 14.5X19 aluminum 3 blade prop. Rinker tech rep tells me it is the correct prop for the boat. I believe I should be getting better performance across the spectrum. The hole shot is OK but but the boat labors to get on plane with a few passengers and a skiier. It's diffucult to keep it on plane below 20mph. The tachometer says RPMs are 5600 and the GPS speed is 50mph at WOT when just me and the wife are on board. It turns a few less RPMs with 3 kids along. Specs say WOT should be between 4600 and 5000 RPMs. I never hit the motor's rev imiter so I assume the tach is incorrect. I want to try a different prop but don't want to hurt the holeshot or hit the rev limiter. Gas consumption is good so far (~5gph) but I have not run it hard for too long yet.

I've been told do almost everything from adjust the pitch, to add trim tabs, to add a whale tale to the drive, or to add cupping to the current prop. Dealer wants to sell me new prop. He's not much help. Any input will be appreciated.
 

mvn

Petty Officer 1st Class
Joined
Jul 25, 2007
Messages
204
Re: Rinker 192 prop issues

Tim,

I had very similar issues to yours and had several others as well.

The first thing you need to do is get your tach issue resolved. You can't tune the performance of your boat with an inaccurate tach.

Having said that, your 5.0L GXi WOT max rpm is 5,000. Is your final drive ratio 1.51:1? I assume you have an SX drive.

The first thing you should consider is to add a set of Nauticus SmartTabs (SX9510-60). They will decrease your minimum planing speed to roughly 16 mph, they will decrease your time to plane dramatically and will help with cruising speed porpoising. They will also improve lateral stability. Stay away from fin stabilizers (whale tails) since they will decrease lateral stability considerably.

Once the tabs are on, I would then recommend a 4-blade cupped stainless steel prop such as a Stiletto or Turbo. I'm thinking that the 5.0L should easily turn a 14.25 x 20". With a drive ratio of 1.51:1, your max rpm will be 4800 and your max speed will be 53.0 mph (this is all theoretical of course).

I have a 14.25 x 20" on my 4.3L for loaded watersports and a 14.25 x 22" for lightly loaded cruising. I'm good for just over 45 mph.
 
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