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


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> .

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=""></a> . You could always
shoot him a question there. He usually recommends buying Stilletto
(sp?) props from , 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!