Hello, looking to re prop my 2520Xl with twin 150s cant seem to find much other than stock they came with 13 3/4 x 19. Has anyone seen better performance numbers switching to 4 blade? Most of my trips will be long runs so looking for something i can get as close to 2mpg as possible.
Props for 2520 xl with twin 150s
- Thread starter Tides39
- Start date
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You infer that you have 3 bladed props when you say 'switching to 4 blade'. There are alot of variables involved, however when I switched from a 3 bladed Yamaha Saltwater Series II 3 blade to a PowerTech ELE series 4 blade, I lost mileage. This is what I was expecting because all things the same, the 4 blade will not be as efficient. It gives you better torque climbing on a plane (my bigger need). Generally speaking, the performance improvements of 4 blades are bite coming on a plane and midrange (plus lower tendency to cavitate in turns). Mileage in not normally expected to improve.
In all my experience with 4 blade props i have been able to cruise (stay on plane) at a lower rpm wich in turn increases fuel economy. i guess my biggest question is what size and pitch are people running not as much as it is a question on better performance. Thanks
Antidote
Well-known member
I would call or email Ken at PropGods. I did and he recommended Powertech 4 blade props for my twin 200s. Full power hole shot is completely flat (II never lose sight of the horizon over the bow), Lower plane speed and better fuel burn at cruise. The trade off (If you consider it a trade off) was losing 2 MPH off the top end. If you are making full RPM with the three blades you will need to drop 1" of pitch on the four blades.
got_em_on
Well-known member
We used ken at prop gods a while back and wound up with Mercury rev IV props. Big difference with stern lift, control when docking, held boat better into a chop, lower plan speed. Fuel burn was not a priority since we are not doing a lot of long runs. We have 05 yamaha 150s and in average to good conditions may average 1.7-2 MPG. never a consistent 2mpg though. I don't think we really lost anything off top end speed, but never run that fast anyway. RPMs turn up to 5,900-6000. The stainless props are heavier and you may wind up with "prop chatter" at low RPMs up to 1,000. Just swap out the hub to Mercury Flo Torq IV hubs and they will be smooth.
Also check your engine height-if you are mounted as deep as possible it may not be needed-the deeper motor is down, the more drag (especially from 2 motors) and less efficiency.
Newer motors are not as thirsty so depending on the year of your motors, motor height and prop suggestions from Ken you may be able to hit that number consistently.
Also check your engine height-if you are mounted as deep as possible it may not be needed-the deeper motor is down, the more drag (especially from 2 motors) and less efficiency.
Newer motors are not as thirsty so depending on the year of your motors, motor height and prop suggestions from Ken you may be able to hit that number consistently.
