Parker Yahoo Group Archived Messages
| ID | From | Subject | Date | |
|---|---|---|---|---|
| 96 | parker25lc | Re: Prop selection for 2520 DV/SWS250 for FishinFireman | 1/20/2004 14:00:00 | |
Bill: Your Yummie OEM manual should state something like this: "At full throttle and under a MAXIMUM boat load, the engine RPM's should be within the UPPER half of the full throttle operating range, as listed in the specifications ... Select a propeller which fulfills this REQUIREMENT. If operating under conditions which allow the engine RPM's to rise above the maximum recommended range (such as light boat loads) reduce the throttle setting to maintain the proper operating range." IMHO that 250 is way under propped and you should be at 5700 RPMS, per Yamaha's Service Bulletins for that outboard @ <a href="http://www.yamaha-">http://www.yamaha-</a> motor.com/products/otb/perfbull/2StrokePerf_OX66SaltVMax.htm . That factory prop you have has an outstanding reputation and I'm surprised you're not higher in the band. I can't tell you the exact prop to get but have you considered a 4-blade? You will see an increase in crusing speed and acceleration, though you will a few off the top. Another point, sometimes one can raise the OB up one bolt hole to add RPMs. There is an outboard guru/marine surveyor who goes by the nickname of "Dunk" over on the FL Sportsman's Forums @ <a href="http://outdoorsbest.zeroforum.com/zeroforum?id=16">http://outdoorsbest.zeroforum.com/zeroforum?id=16</a> . You could always shoot him a question there. He usually recommends buying Stilletto (sp?) props from www.overtons.com , as you buy 2 and try them, then return the one you don't want and they credit your C-Card for the 2nd one. Wherever/whatever you buy, make darn sure you can return it if not right. Same diameter and pitch props from different Mfg'rs perform differently ... weird science I guess. Sorry I could not be of any more specific help ... cheers! | ||||