Merc 115 T.O.P. prop/speed ??

[rick12167]

So I did search the forum on this and wasn't sure there was an answer I wanted to hear.Just put my 78' Predictor in last weekend after a 7-8 mth resto...ran really good motor is strong..I had a 17p on it when I bought the boat ,and after checking out forums bumped up to 21p aluminum.Boat runs 55-58 on water speedo 2 adults and 11 gals of fuel.I'm assuming thats max? No jackplate on boat.Question: any more mph to be had, or do I look to purchase the 98' 200 merc listed on craigslist for $1800.00.This is my first ob and first check..love the boat handles great...I need low 60's to be happy does that mean repower? thanks

 

[atc250r]

Need to know true speed with a GPS (lots of apps out there that'll do it on your phone) and what RPM you're turning. Also, what kind of prop are you running? A good stainless sized properly might get you there.

JOhn

 

[jumbofordman]

Need to know true speed with a GPS (lots of apps out there that'll do it on your phone) and what RPM you're turning. Also, what kind of prop are you running? A good stainless sized properly might get you there.

JOhn

Jackplate will probably get you a few more MPH. I would be wary of a 98 200 on a Predictor. I had a 80's Merc V6 2.0 150 on mine and the rear was barely floating. After it blew up, I got a deal on a 95 2.5 Mariner 175, and the water was lapping over the stern, plus the boat hopped even at max trim until you got over 40, which didn't make for good skiing. I found a great deal on an Eluder, put the motor on there and no longer worry about the boat sinking. I'd like to find a 115-125 to put on the Predictor.

 

[wired]

So I did search the forum on this and wasn't sure there was an answer I wanted to hear.Just put my 78' Predictor in last weekend after a 7-8 mth resto...ran really good motor is strong..I had a 17p on it when I bought the boat ,and after checking out forums bumped up to 21p aluminum.Boat runs 55-58 on water speedo 2 adults and 11 gals of fuel.I'm assuming thats max? No jackplate on boat.Question: any more mph to be had, or do I look to purchase the 98' 200 merc listed on craigslist for $1800.00.This is my first ob and first check..love the boat handles great...I need low 60's to be happy does that mean repower? thanks

Your'e probably going 52-53 MPH. If I'm going 52 MPH in my enticer my speedometer says 60 and thats after 3 speedos and 3 pitot tubes. I gave up and use the GPS. With the wrong prop I can go 65 MPH GPS with the warmed up 150. I say wrong because I had to much bow lift and anything over 60 MPH was whiteknuckling it. With the right prop the bow is barely off the water and its rock solid stable up to 62 at 5800 even though that 26 pitch small ear chopper is slipping like crazy at 16% . Smooth as silk with no torque steer. A 19 pitch Solas 4 blade Titan with go 58 MPH in mine at 6200 but its 3 handfuls to drive that fast. Leaps right out of the water though

Anyway, A jackplate might get you 2 MPH but it will exacerbate the stern weight problem a 200 will cause. Dont get me wrong. I run a late merc 6 on mine and its balanced OK without the jack plate. With the jackplate it was a PITA. Every time I stopped water would gush over the stern. FWIW you'll easily hit 70 with a 200. IMHO too much bow lift on your boat ( and my boat ) makes them undriveable. 60-65 GPS with a little trim and its all fine. Ive had mine 77 MPH but that was with a 225 and a 260 and almost no trim while PLOWING through the water with the bow a foot off the water. Trim any higher and it would get unstable fast.

 

[rick12167]

24p SSteel on the way

So I bought a 24p ss Lazer II off ebay for my Merc 115 ..the 21p aluminum is nice but I want 60-62 mph I'm hoping this gets me there ...no jackplate don't really want to invest in that for what may be very little gain speed wise..I'm just looking for top end ,and i'm usually alone in the boat...I guess 26p may be an option..I'll post results