SS prop guessing game

[Major Mark]

I have a new Targa 17 DC w/115 Opti w/13x19 Black Max aluminum prop. With the livewells full, fuel full, 3 batts in rear, 500 pounds of 2 people, etc it seems to not quite perform quite the way I would like. So far after about 6 or 7 hours on the motor I seem to peek rpms @5200 & it seems to have a huge amount of bow lift at "give'r" time. I've always said I'd switch to a SS sometime after break in was accomplished, which I'm also not sure is over yet, but I'm getting close to SS switch over time. I have been told a 13x18 Vengenance, 13x19 Vengenance, 13x17 Trophy Plus, etc. Top speed isn't a huge issue for me, I'd rather have the bow come down on plane sooner. All the dealers seem to be "guessing" slightly different, thus I'm wondering if anyone else has a boat close to my specs (stern heavy?) who played the game already & came up with a winner prop? Or could excessive bow lift mean a mis-mounted motor? I can't trim the motor all the way down on the trailer without the skeg hitting ground with several inches of trim left to go to ducked position, & that's with the jack leg cranked all the way up. Isd it too low on the transom?

I found 1 dealer with a used 13x18 Vengenance for sale for $225, & willingness to let me try it out for a day or two, any thoughts on how that would perform.. seems like a fair price??

Thanks,

Maj

p.s. the Merc prop selector is now fixed to allow choosing the 115 Opti finally, it suggests for my boat either Black Max 23 pitch or a High five 22 pitch??? Now I'm really confused, everyone is telling me to go down to 17 or 18 pitch, not up to 22 or 23..

 

[JAMES MOORE]

The 18 pitch vegence should be a good fit to get you out and on plane quick with less bow lift. If your running wide open all the time though you might find the 18 allows your motor to hit your rev. limiter. Only way to find out is run one. Another cause for excessive bow lift is the engine mounted to low below pad. I suspect Pat will hop in on this one and give you more info.

 

[Major Mark]

I very seldom plan on utilizing the WOT for excessive long runs, mostly short spurts. The motor is mounted in the 2nd hole from the top, out of the 5 in the motor mount. If I'm understanding correctly what others have told me, every 1 degree of pitch change would be a rpm change of 200? If the motor is rated for 5750 max rpm & I'm at 5200 (about) now, I should have 550 to play with in increase. Again though, not sure if the motor is totally past the break in routine, most likely not yet, which may mean I have more rpm to come yet with the current configuration?

 

[mike chip]

mark,

your break in time on that engine is 5 hours. which is recorded for every in the puter so if you have a claim they can find a way to void it. your engine sounds to low raise it up a notch, the opti have a hard 5750 red line with no give. hopefully pmgoffjr will jump in here, he sould no your answer for sure.

mike

 

[paul white]

for every number you drop the pitch will increase ur hole shot, but decrease ur top end speed if its a big decrease in pitch. if it was me id go with a 17 since speed is not ur worry. i had the same peoblem and decreased my pitch on my ss prop 2 numbers and it helped hole shot and increased the rpm 400 and increased the speed 3 mph. every number you go down in pitch, the rpm rises 200 per number......thnx.....paul.