Originally Posted by ktron

Post the video so we can see how it accelerates.

Originally Posted by mikebrls

I love the boat , but just prop it to run 105 to 108 fully loaded with fuel and peep's and be done . The way I saw the other boat in the video running look's dangerous for the average boater , one boat wake come's by with the bow so high we will be reading about you and not the good way . if you want the boat to run 120 then build it to do so properly without the risk of a accident ." I/O's or 7 marine

Be safe and forget about that one time top # the next guy will always be faster

mike

Originally Posted by Nastybug

Thanx for the kind words guys. We're all in this together. Ha. So I ran my Dewalds the other day. They are 34pitch 15.25 dia and 20 degree rake. I ran 111mph at 6441 rpm. They are on their way back to him for some adjusting. I think 33 pitch by 15.25 dia would be perfect. He's gonna start by taking some cup out which he left a lot of in this time around. Also bit of Dia. we will see what happens. Im sure they'll have to go back one more time before were done. My last run out with my Merc props was 114mph at 7049rpm. Im sure I was one tick off of 115mph. I have a problem with my starboard motor as it runs 300rpms behind my port. Its been that way all season. The heights have been rechecked several times and the Dewald props yielded the same info. My girlfriend videos the vessel view so I could stop it to see where they were at certain speeds. If I got that motor to pull its own weight equal to the port motor Im sure Id be up around 117 or 118mph. That last run the port was on limiters with nothing more to give and the starboard was lagging behind. I think the Dewalds will put me at 115mph very conservatively and that 300rpms would yield another 2mph conservatively. Being that new 318 that just ran did 121?mph I think with my boat with two healthy motors could get close to 120mph with the set up as is. Understanding I ve been running in 70 degree weather with mild humidity which is perfect speed testing weather. Take the above for what they're worth. I did up to 114mph the one day with 2 people on board and about 110 gallons of gas so I think my projection of 118mph plus is totally attainable with two healthy motors. Im working on getting that fixed soon. Hopefully its not a major headache but you never know.

Originally Posted by 28skater

I'm running 300xs'- and the port motor is always a few rpm ahead of the starboard. Its faster, but also more fuel efficient which is weird. Isnt this common, port motor being faster?

Originally Posted by 28skater

I'm running 300xs'- and the port motor is always a few rpm ahead of the starboard. Its faster, but also more fuel efficient which is weird. Isnt this common, port motor being faster?

Originally Posted by mikebrls

if this is correct then it could take a extra few HP to turn the prop one way vs the other ?

Originally Posted by Nice Pair

I've been running twin outboards for about 15 years on different boats and have seen the motor with the counter rotating lower consistently turning 200+/_ rpms slower.

I've always believed the difference to be the way the lower handles the thrust. (front tapered cone bearing R.H.) (flat needle thrust bearing L.H.)
The counter rotating also runs hotter and will "burn" the oil faster.

My $.02

Originally Posted by Skater30

Interesting........if you click on the link and watch the video of my tachs, you'll see that my 300XSs run almost identical rpm at WOT. But not everyone will take the time to do what it takes to make this happen either.

https://www.youtube.com/watch?v=RWSPBLFvPFE