volvo-penta prop selection

[jdjb56]

i purchased new props for my 1988 26' imperial aft cabin this past winter. i have a volvo-penta 290 duo prop engine 350 gm. the marina discarded my old props so i don't know what size they were. from the first time out i have lost power, speed, rpm and<br />fuel effeciency. i used to cruise 3/4 throttle @3000 rpm and 25mph. now at full throttle i barely reach 2800rpm.<br />the props he sold me are B5's. any suggestions?? <br />thanks jim<br /><br />the boat- 26' / 5300lbs / loaded 6300lbs

 

[stevens]

Re: volvo-penta prop selection

Sounds like your prop pitch is much steeper than before and that you'll need to move to something like B4 or B3's.<br /><br />I think you should go back to the dealer and insist on trying out props until you find the set that is right for your boat.<br /><br />The pdf-download from this site (link) may be of help. Good luck.

 

[KnottyBuoyz]

Re: volvo-penta prop selection

Jim<br /><br />I've just been down that road with a similar boat and drivetrain. See this thread.<br /><br /> http://forums.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=40;t=000368 <br /><br />B5's were the solution for us. 1987 26' Sunray Mirage AQ271A (350 270 HP) & AQ290DP outdrive, 4500 lbs dry, 5500 lbs loaded. I was way over propped but not nearly as bad as you. I would suspect something other than just the prop with a degredation in performance that bad. Each series of prop is about 2" of pitch and 200 RPM. You'd have to have gone from a B2 to a B8 to see those kind of numbers. My gut is telling me there's something else holding you back.<br /><br />Rick