90.5.jpg
Odd; this pic is from my Mercury 250XS with 1.75 sporty running a stock 29 ProMax
Somebody must have stamped yours incorrectly as I could not hit 90 running a 28 ProMax but hey, that's good running regardless.
I'm going to bring it to Robbie to measure up in Jan. with the sporty.. so then we should see. Thx!
Hey all the experts know you can’t run 90 mph with a 28 pitch prop and 175 gears. ;-)
Sure you can; just need 2% slip or a raised limiter. We can see his rpm's so I'm sure the prop is built a little better than most to get those kind of numbers.
The numbers I ran were showing 6% and my boat was full of fuel, all my gear and 75 pounds of shot. 5% should be attainable with a good set up.
Last edited by scj; 11-13-2017 at 01:04 PM.
My boat was mostly empty but nearly full tank of gas and just me... No shot notta. .a few vests and the bike seat and 2 poles and that's about it... so with that being said... Now what lol
So according to you guys.. maybe i have 2 30 Promax's and don't know it
Maybe Lee was right... The water is harder up in CT
If Robby did a great job on the 28p it is probably attainable. If you check the prop slip caclc you are at 2% slip with the 1.75, and 9% with 1.62's. I ran one of my props the other day and checked the speed/rpm on the prop slip and this prop was at 1%. The props I have usually run between 6 and 9% slip. I am questioning weather it was an anomaly or false readings on the MM and Lawrance as I went fishing after that and didn't make another run. What ever you have, hang on to it as it should work good in summer with 2 in the boat. I team fish with a 28p q4xob and 1.75's. Never ran a Promax.
I need to send you my Promax Dean so you can say your ran one.......
Allison XB21 2+2
Mercury 300R
This isn't the first time a prop has ran faster or slower than what the formula says it should.
Even though the math is correct there are to many variables for it to be written in stone....
I believe those who have ran a pro-max will agree they run a lot stiffer than most other Mercury props.
Most good prop men can change a prop 1" in (given pitch) without changing the pitch--- just add the right cup.
I've owned several Mercury props that are only cast in even numbers --to get an odd number they simply change the cup. Years ago I had a magical Mercury chopper worked by Dave Bostic.. --it ran a lot better than the formula said it could. He claimed it was "a little stiff" to start with according to his pitch blocks. Which is another variable -- not all pitch blocks are the same..
Last edited by fishnfireman; 11-14-2017 at 09:00 AM.
Mike, your right. I have a 34rl P3 that runs the same as the 32bc P3. They are both probably going to be worked again as they don't seem to work the way I think they should.