I have a 29' Larson with a stepped hull and twin 4.3gl VP sx
outdrives. I have a significant ventilation problem when in 2-3 seas
or more. I have been working with Larson to fix this problem and from
my research stepped hulls seems to have a tendency to have this
problem. I have sanded the aft section of the hull smooth to minimize
turbulance and now need to change props. I am running 14 1/4 x 23 OMC
vipers and am looking to move to 14 3/4 x 21 to get some more blade in
the water. From what I have read I need and prop with a high rake and
cupping and am looking at the viper or mercury mirage plus. I am
concerned about the mirage due to some things I have read, does anyone
have any expirience with this prop? I am also wondering about 4 blade
props, they seem to be designed for just my type of problem (holding
power, high mounted drives, medium speed cruising), but don't know
anything about them. Any advice on these or other types of props you
think would work well for me is very appreciated. I lost most of last
season due to this and want to get it right this year. For info I run
@ 4600 with a clean bottom with my current props.

Thanks,
Rich

I would go for the 4 blades which will do exactly what you want. The Merc
Revolution 4 should be the right prop. I would go w/ a 21 in this case as
it should be right at max rpms. Should give you great planing ability and
you should never ventilate again.

--
Tony
my boats at http://t.thomas.home.mchsi.com



"Rich" wrote in message
om...
I have a 29' Larson with a stepped hull and twin 4.3gl VP sx
outdrives. I have a significant ventilation problem when in 2-3 seas
or more. I have been working with Larson to fix this problem and from
my research stepped hulls seems to have a tendency to have this
problem. I have sanded the aft section of the hull smooth to minimize
turbulance and now need to change props. I am running 14 1/4 x 23 OMC
vipers and am looking to move to 14 3/4 x 21 to get some more blade in
the water. From what I have read I need and prop with a high rake and
cupping and am looking at the viper or mercury mirage plus. I am
concerned about the mirage due to some things I have read, does anyone
have any expirience with this prop? I am also wondering about 4 blade
props, they seem to be designed for just my type of problem (holding
power, high mounted drives, medium speed cruising), but don't know
anything about them. Any advice on these or other types of props you
think would work well for me is very appreciated. I lost most of last
season due to this and want to get it right this year. For info I run
@ 4600 with a clean bottom with my current props.

Thanks,
Rich

There are a few shops around the country that specialize in propellers and
their problems.

Contact Phil's Propellers in Northern California, USA

http://www.philsprop.com/



--
Bill Kiene

Kiene's Fly Shop
Sacramento, CA, USA

Web site: www.kiene.com


"Rich" wrote in message
om...

I have a 29' Larson with a stepped hull and twin 4.3gl VP sx
outdrives. I have a significant ventilation problem when in 2-3 seas
or more. I have been working with Larson to fix this problem and from
my research stepped hulls seems to have a tendency to have this
problem. I have sanded the aft section of the hull smooth to minimize
turbulance and now need to change props. I am running 14 1/4 x 23 OMC
vipers and am looking to move to 14 3/4 x 21 to get some more blade in
the water. From what I have read I need and prop with a high rake and
cupping and am looking at the viper or mercury mirage plus. I am
concerned about the mirage due to some things I have read, does anyone
have any expirience with this prop? I am also wondering about 4 blade
props, they seem to be designed for just my type of problem (holding
power, high mounted drives, medium speed cruising), but don't know
anything about them. Any advice on these or other types of props you
think would work well for me is very appreciated. I lost most of last
season due to this and want to get it right this year. For info I run
@ 4600 with a clean bottom with my current props.

Thanks,
Rich

I am running a set of Turbo Ultima 4 ( four blade). You can log on to my web
site and read the section on prop testing which may save me some typing
here.. I am now running these props at + 5". Even with this high drive
height and trimmed way back plus running in a seaway, I cannot blow them
out. I can't say they would be best for your boat but they work really well
on mine. You should find them to be a cost savings over the Merc or other
Engine mfg branded props. I visited the Turbo guys at the recent Miami boat
show and they are soon to introduce a new hub design that will eliminate
spinning hubs ( which have been a problem for me). The new props will have
more dia as well. I plan to buy some when they are available. Probably any
four blade will help but these are the ones I have experience with and I
know they are well designed.

--
Ron White
Boat building web address is
www.concentric.net/~knotreel