LOTS of prop slip
09-04-2012, 04:06 PM
#11
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Yes i am triming out to get air under the hull and let the steps do there job and lift the hull the boat comes up and runs on the keel pad like it should it just dosent gain any speed
09-05-2012, 01:49 AM
#12
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It sounds like when it lifts, that the props are losing bite and slipping more. A 1/2" or 1" spacer will do a lot. Are you throwing a decent rooster tail when trimmed up???
09-14-2012, 02:13 AM
#14
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Something is definately strange about your issue. If you're not really throwing a rooster tail when trimmed up, then the dirve height should be fine.
Your prop slip at 4600rpms is 11% and at 5200rpms its at 21%. If you kept the 11%, then you'd be at 91mph.
Are your speeds on a gps????
Have you tried subtle changes in the trim when trimming up...like a 1/2 number at a time. Fountains are designed to run flat. Let the steps do their job. How high are you trimming???? The indicator only goes to 7 on Fountains. You should probably be around the 6 for max trim.
Your prop slip at 4600rpms is 11% and at 5200rpms its at 21%. If you kept the 11%, then you'd be at 91mph.
Are your speeds on a gps????
Have you tried subtle changes in the trim when trimming up...like a 1/2 number at a time. Fountains are designed to run flat. Let the steps do their job. How high are you trimming???? The indicator only goes to 7 on Fountains. You should probably be around the 6 for max trim.
09-14-2012, 08:18 PM
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Yes the speed is on gps my indicators go up to 8 and and on 5 at wot the boat is running very flat and 81 mph at 4600 rpm if i go up to a 7 1/2 or an 8 it picks up and starts to air out and gets the rpm up where they should be 5000 to 5150 if the boat should run more flat like it dose at the 5 or 6 position would dropping down in props and getting into the rite rpm range there help
09-14-2012, 08:46 PM
#17
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I went through a slew of props for my boat. Not a stepped hull, but I get 89 with 525's and 7 people. Trimming up to much will actually loose speed, but RPM's will go up. You DO HAVE too much slip. You also need some hulll lenght in the water to provide lift. 525's actuallyput out about 550-560 on the dino. some more some less. YOur horses are ok. but I think it's a trim issue. Try to use 32 labbed keep the drive neutral or a bit up and lower your tab a bit. This will keep your RPM's up. gettiing all the ponies, and still get your lift having enough hull lenght you want to have your prop shaft parrallel to the water as much as you can. Trimming to high your props will "dig" nto the water instead of pushing you forward. Pushing stern down, won't get you speed, keep experimenting. you should run 90. You might try spinning in.
