Need prop advice for 93 Rinker Captiva 209 4.3 LX alpha gen II for high altitude

[mcmarcia]

Hello all. Newbie boat owner needing some advice on how to find good prop choice for both lake Powell at around 3500 ft and Lake McPhee at 6900 ft. Boat was being used at a 6000 ft lake and prior owner bought a new solas amita 14.8 X 17P prop this year. On test ride with 4 people at 6K elevation it got to 36MPH at WOT and 4800 RPM according to the boat gauges.

I bought the boat and I took it out to lake powell for a 6 day trip last week with a friend and a bunch of camping gear and other weight. My friend with a 50 ft houseboat and a 19ft searay says I got a smoking deal and the Rinker out performs his searay, so stoked my friend approved of my new/old boat. It seemed like the current prop got it up to plane very quick and worked well for the weight of gear, food, water and gas (50 gal tank plus extra 24 gallons in containers). But when boat was empty with just me I tried it at WOT and it got up to over 40MPH and the RPM's were still rising and just under 5000 when I saw it was going above the 4800 max WOT RPM and cut it back.

I know next to nothing about all this, but am concluding the current 14.8 X 17 prop is going to be good for a loaded boat or very high altitude, but could be problem if it over rev's motor. I know I need to have 2 props anyway so I am looking for some choices. I might go with a 4 blade quicksilver nemesis in a 14 X 19 for good holeshot and handling or 3 blade 19P for a general purpose prop. I tried using the prop finder on quicksilver site and it is recommending the 14 X 19P nemesis or a 18 or 19P for a 3 blade prop if I spilt the altitude at 5000 ft.

I think the dry weight is 2900 lbs, about 20.5 ft long, measures 106" max width/beam, has a 4 BBl endelbrock carb/manifold and new block in 2007 with under 200 hours.

I really do not care about going fast, just want to max out fuel efficiency, good handling at slow and cruising planing speeds, be able to pull a skier up or other water sport toys and be good overall for the 2 altitudes, 3500 and 6900 ft. Maybe I need 2 props for the 2 lakes?

This may be my first post? I have been reading a ton on your great site and appreciate any advice, thanks so much!

 

[WesNewell]

All a matter of preference. Maybe a 19P of the same prop model for the lower lake and the 17P for the upper lake. Or just keep the throttle and rpm down on the lower lake with the 17P. Basically, there's about 10% difference in HP provided by the engine at the different altitudes.

 

[Scott Danforth]

if you dont care about going fast, simply do not go to WOT empty and watch your RPMs a the lower elevatins. you control the throttle.

otherwise you need a different prop for each elevation. you should also re-jet the carb at the higher elevation.

 

[mcmarcia]

Thanks for help. I bet it might need some re jetting for the 6900 ft lake as prior owner said sometimes he had to spray some starter fluid when he was on his 6000 ft lake. But I did not have that issue last week on powell at 3500, started just fine. Only start issue is every once in a while turning key to start did nothing, but that was not to often and next attempt it started up fine. I am thinking that is a bad ignition connection (?) and sprayed a tad of triflow into the switch.

Carb re-jetting, if it needs it, will be for next summer as it is starting to cool down and will probably try and stick with lower elevation lake powell to enjoy some nice warm fall weather. Boat has been in UT and CO since it got a new block in 2007, so hoping it has been set up already with jetting.

I found a new 4 blade nemesis 14X 19 I got coming from ebay, that might be a better low elevation prop and I can keep the 14.8X17P as a spare, for the 6900 lake or big loads.