What would I gain from this scenario???

Well just as always the marina wants to make "money" on their parts and advice. I have a 19.5' Sylvan V196 with the Mercruiser 4.3LX Gen+ and the AlphaOne outdrive. What I have for a back up to get me by since the wifey smoked my 4 blade is a 3 blade 14.25" 19 pitch prop. The marina "techie" as he calls himself wants to sell me a 17 pitch prop. I honestly never have gotten above 35 mph at maybe 4,200 rpm with just 500 lbs of people and gear and a boat weight of 2,400 lb. The motor is very well tuned in and the carb is rebuilt and idling perfect at 650 rpm in forward gear. It just seems like this motor can do more and the "techie" wants me to drop $150.00 on his "golden answer to the issue." I already have a hydrafoil for planing faster and it does make a difference. Any thoughts? Sorry for the added thread but I couldn't respond to my other thread.

Re: What would I gain from this scenario???

you can get an aluminum prop here at iboats for about $100. I think the RPM goal for that motor is about 4500, so a 3 blade 17 pitch prop sounds about right, trim tabs will help a lot with hole shot and planing faster. sometimes the trim tabs will raise your RPMs slightly at WOT, if you are considering them you should get them installed first before changing props. you are about at the top speed for your set-up. What is the HP of that motor??

Re: What would I gain from this scenario???

According to the manual and the manufacturer the it has 180 h.p. I'm not asking for much but I wondered if dropping the pitch down to a 17 (3 blade) would do any more justice to the overall speed of the boat. If I went with a 17 pitched prop should I change the diameter from 14.25" to ??? or leave that alone?

Re: What would I gain from this scenario???

Tell him to let you try it out before ya buy.... If ya like the results........................................

Re: What would I gain from this scenario???

While the foil may help your hole shot it is very likely sapping some of your top speed.
Also the 4 blade will help hole shot and ability to stay on plane at reduced throttle but will also reduce top speed.My info indicates wot rpm is 4800. Also there is a 160 hp version and 180.
Going to a 17" 3 blade "could" add about 500 rpm while helping to maintain hole shot
and very likely increase top speed.If the foil is causing drag removing it you might gain some speed as well.You may say your not concerned with speed but keep in mind increasing speed at a given throttle setting increases mpg.

Re: What would I gain from this scenario???

160-180 HP on a 20 foot boat looks like about 35-40 MPH, I had a 20' edgewater CC with a 200 outboard that could hit 50 MPH loaded, I currently have a 20' well craft cuddy with a 200 outboard on it does about 45MPH unloaded, the hull makes a big diff. so if you have the 160 HP motor you are about at the top of your speed range, only a couple of MPH possible gain by changing props, maybe even lose a couple by going to a 17.

Re: What would I gain from this scenario???

If your 4,200/35mph speed is absolute full speed wide open throttle?

Then "techie" is absolutely correct. You are under-revving/lugging the motor because you have too much pitch, and going to a 17 will make your boat quicker out of the hole and maybe even faster because you'll be in the peak HP range of your engine.

As stated, ask him for a test drive....or an exchange/trade-in option. If you like it, you'll buy it....