Prop Questions

[elevatorguy]

I bought a 2000 1850 Sportfish with a 125 merc on it. It currently has a 13 3/4 x 17 pitch stainless prop on it now. When I took it out I could only get about 36 mph on the GPS and hit the rev limiter too easy at approx 5600 rpms. I was hoping for a little more top end. So my question is who out there has a similar setup and what kind of performance do you see? I am wanting to change props and thinking of going up to a 21 pitch. And of course I know, until I can get it in the water with a different prop to try I am just spinning my wheels. So I just thought I would throw it out there to see what people think. This way I have a good base to start with whenever I get my boat in the water, which with the way it is going it may not be till may. So as you can imagine I am chomping at the bit to tinker with this boat and get her dialed in for opener!

[harvey lee]

I have Jay at Soderbloom's do my prop work and he has helped me figure out what prop would be best for my boat.

he knows alot about proping a boat.

Give him a call.

[Kyhl]

Yep, seconded. Call Jay.

[elevatorguy]

Thanks guys. I didn't realize they did props. Actually a guy I work with knows Jay really well. I will definitely give him a call. I was also gonna talk to the Prop Shop right here in Duluth and see what he had to say. I was also hoping some people would chime in and say what kind of performance they got with similar setups so I can see what I might expect from my boat. I was thinking a 21 pitch would work cause I know a guy who had a 1800 pro v with the same motor. He had same rpms and speed with a 17 and when he went to a 21 he could flirt with 45 mph. I was just hoping to get over 40.

[delcecchi]

I bought a 2000 1850 Sportfish with a 125 merc on it. It currently has a 13 3/4 x 17 pitch stainless prop on it now. When I took it out I could only get about 36 mph on the GPS and hit the rev limiter too easy at approx 5600 rpms. I was hoping for a little more top end. So my question is who out there has a similar setup and what kind of performance do you see? I am wanting to change props and thinking of going up to a 21 pitch. And of course I know, until I can get it in the water with a different prop to try I am just spinning my wheels. So I just thought I would throw it out there to see what people think. This way I have a good base to start with whenever I get my boat in the water, which with the way it is going it may not be till may. So as you can imagine I am chomping at the bit to tinker with this boat and get her dialed in for opener!

If that is the 2+2 2stroke 125 merc, I think 5600 is a little high.

[elevatorguy]

Hey Del it is a 2+2 and 5600 may be off a little and that's why I put approx in the first post. That was a long time ago and I was just trying to go off memory. I just know I hit the rev limiter way too easy and it was in the low to mid 5000 range in the rpm. And I didn't get much time on the water with it.

[waterwolff]

I think a 21 pitch prop is way to much for that motor.If you were indeed hitting 5600 rpm's at wot and your rev limiter is set for 5250 rpm's. I would guess you would be looking at a 18 or 19 pitch but that is just a guess. There are a lot of variables that come into play in selecting the right prop. When you took your readings were you alone, did you have a full tank, was the boat fully loaded with your fishing equipment. Do you plan on pulling tubers or skiers.

[Kyhl]

Step one, what is the motor's optimum recommended range? Aim for the high end of that.

Step two, find out the actual rpms under the current 17" prop.

Say the optimum is 4,600-5,000, then you might want Jay to do a 19" with double cupping that would allow you to hit 5,100 under no load, 5,000 when loaded, otherwise a 21" might drop you down to 4,800.

Do you troll? Anything bigger than the 17" will increase your trolling speed, about 10% per 2" of change. So if you were doing 2mph with the 17 then you may end up with a minimum close to 2.5 with a 21.

[elevatorguy]

Waterwolff thanks for the input and I do understand there is a lot of variables and I do have to get it back and double check the rpms.

And Kyhl I did talk to Jay and I am definitely gonna go with him. I think we are gonna start with a 19 pitch and then it sounds like he can dial it in from there to get what I want out of the boat. And as for trolling I do have a drift sock and have used 5 gallon pails with a previous boat I owned. So those are an option for now but I will eventually get a kicker for when I can get time to get back out on Superior.

I was still hoping for a few guys to chime in with their setups and what they get out of them. I am just itching for spring and to get out there. I am so ready for spring!

[DooWap]

Elevatorguy,

I run 2002 Pro V 1800 (pretty similar size to your boat) with a Yamaha 150. I'm spinning a 19" prop at 5400 RPM WOT. Depending on how much fuel and people I have in the boat I'm usually hitting 48-50 mph GPS on flat water. I would think you might want to start with a 17" prop and see how that goes, the 19" might be a dog out of the hole.

Sorry just realized that you're spinning a 17" right now.

[delcecchi]

Hey Del it is a 2+2 and 5600 may be off a little and that's why I put approx in the first post. That was a long time ago and I was just trying to go off memory. I just know I hit the rev limiter way too easy and it was in the low to mid 5000 range in the rpm. And I didn't get much time on the water with it.

I have a 98 1775 pro-v and used to have a 115 merc 2stroke. I ran a 19 for a while and then a 21 pitch (aluminum right out of box). I got 42 mph on a good day (with a full tank of gas, 3 batteries, me, and a 9.8 merc kicker). I have read that due to something in the design, crankshaft maybe, that those motors shouldn't be over revved. Seems to me that 4800 to 5200 was the recommended range.

I didn't enjoy trolling with the big motor much, since it idles sort of rough and, like all two strokes, smokes.