Took the new to me boat out today not sure what to think all new at this. It's a 2004 882 with a 115 optimax prop is a stainless 5 blade 20 pitch. Boat took for ever to get up on plane like 15 seconds I bet and motor seemed so low almost encased in water trying to get up. My last to boats tracker pt190 had aluminum 3 blade props and shot right up quickly. My ? Is would it be better with a 3 or 4 blade or do I have other issues going on. Past owner used boat very little only to haul his kids around on tubes a few times a year boat is in what appears to be mint condition. Once on plain my top speed was 44 mph on gps but filled tank today and had 3 people along for the 1 st voyage I am sure this dampened my speed once on plane. I can't test it really yet due to ice conditions up here had to drive it to river otherday 2 hrs away. Hoping the lakes thaw out this week. Talke with one marine mechanic other day he thinks the five blade is just to much prop and I need a 3 blade. That contradicts everything I've researched states the merc high five is made for fast hole shots.
I'd go with a 3 blade. Every boat I've ever seen loaded in our neck of the woods has had 3 blades, with the exception of some Bullet drivers with new 400 Verados.
I think that more than being a five blade, you might be over pitched. Most 115's run much better with a 17-19 pitch prop. I'd look that direction first.
Also do you know your prop height? As in how many inches below the pad of the boat your prop shaft is? The things you're experiencing could be from the motor being too high. Water pressure and top end RPM's can help determine if this is the case.
I'd definitely look into a smaller pitched 4 blade prop. If top end speed is your desire then a three blade. A four blade is more stable than a three blade, however with a 115 horsepower motor, you man not be able to notice much difference.
Thanks for the imput! Went to local shop today and they set me up with a Mercury black max 21 pitch?? They wanted me to try it first and will allow me to return it for different one if not satisfied.
Keep us posted on how it does. I had a 115 Evirude that liked a 21 raker, it was tough coming out of the hole but a scalded dog on top end.
5 blades at that pitch just might be too much to turn.
Quote from: pipes18079 on April 05, 2015, 10:17:31 PM
Took the new to me boat out today not sure what to think all new at this. It's a 2004 882 with a 115 optimax prop is a stainless 5 blade 20 pitch. Boat took for ever to get up on plane like 15 seconds I bet and motor seemed so low almost encased in water trying to get up. My last to boats tracker pt190 had aluminum 3 blade props and shot right up quickly. My ? Is would it be better with a 3 or 4 blade or do I have other issues going on. Past owner used boat very little only to haul his kids around on tubes a few times a year boat is in what appears to be mint condition. Once on plain my top speed was 44 mph on gps but filled tank today and had 3 people along for the 1 st voyage I am sure this dampened my speed once on plane. I can't test it really yet due to ice conditions up here had to drive it to river otherday 2 hrs away. Hoping the lakes thaw out this week. Talke with one marine mechanic other day he thinks the five blade is just to much prop and I need a 3 blade. That contradicts everything I've researched states the merc high five is made for fast hole shots.
I own the same boat, the first thing that came to mind when I saw your post was that you listed the engine as a 115 Optimax, are you certain that it is not an ELPTO? Reason I mention this is that I don't believe the Optimax in a 115 was a standard power option for that year and model, there was a 150 Optimax that was available.
Anyway, mine has the stock SS 3 blade prop and it is a 23 pitch. Boat tops out at about 52MPH and runs about 5200 RPM.
Thought it might help.
Well it's been an adventure to say the least to keep it short I will say the 19 pitch black max isn't the right one it puts the rpms to high and sets of an alarm especially when turning so I did get a 21 pitch to try. I will try it out on Sunday. I was getting 48 mph on gps with full tank of gas with that 19. I hope the 21 will be better and I will use it for the season until next year I'll look into a stainless. Motor says optimax on it as does the title for the motor with all the paper work so I just don't know at least I was able to put a few fish in boat yesterday.
Catching fish is always good !
Aluminum props flex quit a bit. A stainless in the 19 pitch would probably bring your RPMs down in range and give you more top end speed.
I'm curious to know what RPMs you hit with the 21
Whelp :surrender: know I am really confused lol I went and took the 19 pitch off this evening to and place the 21 to try and its a different diameter. The 19 is a 13 and the 21 is a 12 3/4?? See me not knowing last week what I was doing put a 14 1/4 inch diameter on and took off yikes let me tell you that turned heads around lake as it slipped over gear case( I think that's what it's called) what a racket. Shop got the 19 pitch at that time and said I need a 13 diameter. Lol well the 21 p they sold me is a 12/34 diameter. I have spent hrs online and can't seem to find a 13 diameter 21 pitch and the shop is closed till Monday. So my assumption is not to use the 12 3/4 21 pitch. :P
The smaller diameter can allow you to use a bigger pitch. It allows exaust gas to pass over the blades and allow them to spin easier. Basically the cause slip. This lets you achieve higher RPMs with a higher pitch.
It should be okay to try the 12 3/4 diameter prop.
I'm late in responding, any new updates from the shop yesterday?
Well I went ahead and just used that 21 pitch it seemed ok I was getting 48 mph and rpms seemed ok only set of alarm when trimmed to high I guess or taking corners then it shot rpm meter up over 6. I guess I just have to get use to driving this boat it different than my past tracker pt 190s I've had
You might have your motor set to high. Both the cornering and high trim causing high RPMs are indications that the motor is too high on the transom. If it is too high, bringing it down a quarter inch to a half an inch could fix these issues and increase your speed :-* By getting the prop deeper it can bite better and create more forward thrust.