25 Sportdeck chine walking
#24
Registered
incontrair the fleetmaster swept back skeg is narrower & longer than a straight skeg sportmaster
u can easily see yourself on the pics from northerns sportmasters and ur pics of the fleets
and a fleetmaster with a nosecone is a faster gearcase when installed properly
the cle gearcase is a better case than the sportmaster is on a bigger heavy boat
but they have been replaced with sportys yrs ago
as the nose point was even with the propshaft
the sportmaster point is lower than the propshaft
this was done to get prop higher,,,,
butt on a heavier boat having to use positive trim the water surface is not even across bottom of housing to prop
hense a slower gearcase,,,,,,,
glad u ordered some expensive gearcases and hope they will help solve ur problem
but a few that have built and raced many O/B boats have given some good advice
vrsing 2-300 each to have cones installed on the fleets and have the straighter bottom housing from point to prop and the longer swept skeg
u can easily see yourself on the pics from northerns sportmasters and ur pics of the fleets
and a fleetmaster with a nosecone is a faster gearcase when installed properly
the cle gearcase is a better case than the sportmaster is on a bigger heavy boat
but they have been replaced with sportys yrs ago
as the nose point was even with the propshaft
the sportmaster point is lower than the propshaft
this was done to get prop higher,,,,
butt on a heavier boat having to use positive trim the water surface is not even across bottom of housing to prop
hense a slower gearcase,,,,,,,
glad u ordered some expensive gearcases and hope they will help solve ur problem
but a few that have built and raced many O/B boats have given some good advice
vrsing 2-300 each to have cones installed on the fleets and have the straighter bottom housing from point to prop and the longer swept skeg
Last edited by johnmiffco; 11-21-2015 at 06:05 PM.
#25
I know that the torquemaster lowers supposedly blow out at speeds over 85. But the lowers causing chine walk, I have never heard of that. I hope the new lowers work for you because you already spent the $, but I doubt that changing the lowers will solve the problem. I am also curious about those props. I have never heard of a 25 with a pair of 250's spinning 32 4 blades. My buddy has a 25 with a pair of 300x's and he can barely spin a 28 b1. What rpm do you spin the 32's to?
Curious to see the end result.
Curious to see the end result.
#26
Platinum Member
Platinum Member
Thread Starter
Turbo rr, after talking with Scott at Merc Racing about the handling issues, he recommended that Sportmasters are the better lower unit given the boat's setup . The Fleetmasters were also not giving my engines the water pressure it needed, even with their low water pickups. I feel he was giving me honest input and not trying to sell a set of lowers. As far as my engines, they were turning about 5500 with the 32s, and 1.75 gear ratio. My engines redline at 5800. With 1.62 Sportmasters, the 32s may be a little tall but I think I can still run them, at least for test purposes. I had a 300X on my old 22 Velocity and they don't seem to have the torque that my 250XSs to. They also turn a lot higher RPM.
#27
Turbo rr, after talking with Scott at Merc Racing about the handling issues, he recommended that Sportmasters are the better lower unit given the boat's setup . The Fleetmasters were also not giving my engines the water pressure it needed, even with their low water pickups. I feel he was giving me honest input and not trying to sell a set of lowers. As far as my engines, they were turning about 5500 with the 32s, and 1.75 gear ratio. My engines redline at 5800. With 1.62 Sportmasters, the 32s may be a little tall but I think I can still run them, at least for test purposes. I had a 300X on my old 22 Velocity and they don't seem to have the torque that my 250XSs to. They also turn a lot higher RPM.
With the sportmasters...make sure that when they are running the bullet is running on the surface of the water and not underneath. Anytime the bullet of the sportmaster is under the water when running you will not have optimal performance. The bullet works like an anchor.
#28
Platinum Member
Platinum Member
Thread Starter
I plugged the 4 upper holes on the Fleetmasters and it didn't help. My engines are 2003s and their redline is 5800. I'm not concerned with ultimate top speed. I had a 28 Skater for the last 8 years so I got that out of my system. My main goal is to make this boat a good all around sport boat, something the Skater was not capable of. I will definitely test engine height when I begin testing the setup with Sportmasters.
#29
Registered
iTrader: (1)
nose cones have a low water pick up
If you run the fleetmasters high you have to plug a few of the upper water intakes with set screws. Mercury recommends to block up to 4 of the eight. What happens is that when run higher, the upper holes suck in air and lower the water pressure. I know some of the 250xs's can spin up to 6200 rpm. You can try the 32's for test purposes, but I still think you will need to go smaller. With those engines it is important to get the full revs to get optimal performance. You would be suprised how much more mph you will get with 300 rpm. Another thing that might help is to send the ecu's to simon and get them remapped. With a smaller boat and a smaller prop spinning a higher rpm you should get more performance.
With the sportmasters...make sure that when they are running the bullet is running on the surface of the water and not underneath. Anytime the bullet of the sportmaster is under the water when running you will not have optimal performance. The bullet works like an anchor.
With the sportmasters...make sure that when they are running the bullet is running on the surface of the water and not underneath. Anytime the bullet of the sportmaster is under the water when running you will not have optimal performance. The bullet works like an anchor.
#30
Platinum Member
Platinum Member
Thread Starter
UPDATE: Ran my boat yesterday with its new sportmasters. High speed handling improved drastically as did my water pressure. I raised my engines so the prop shaft is level with the running surface. It had been .75" below. With the new 1.62 ratio and my 32" Bravos I hit 82 MPH but at only 5200 RPM which is pretty low for my 250XSs. Getting on a plane was a little slow too. I will start trying some lower pitch props to get the rpm where it should be at WOT, and improve time to plane. I will most likely try some props from BBlades since I can demo props and get just what this hull likes.