Hi first time here...great info from what I've read so far...thought I'd just add to some of the data out there for the F70 yamaha..
boat= XP18 Xpress CC with the f70
WOT with 13 1/4 X 15 std 3blad alum 2 peps and 9 gals of gas trolling motor and 2 batteries (with stock tach) @ 6100rpm
Speed (avg up and down river with GPS) 35.8 MPH
Same load as above
WOT with Solas 13 X 15 4blade 6100rpm
Speed (same as above) 35.7mph
The rpm range of 3800 to 4300 saw the better improvment in speeds...not to much but a 2.5 mph increase in the 4300rpm range is ok with me since thats the range I usally run in most of the time.
Speed with the 3blade was 24mph @ 4300 turns
Speed with the 4blade as 26.5 @ 4300
Hole shot was/is impressive with the stock 3blade....maybe its a bit better with the 4blade but not really night and day difference. It almost jumps on plane in the lenth of the boat. I think the transom is riding higher and that's lending a bit more measureable speed on the midrange rpms.
the only quirky thing is this....@ 1200rpm to 1400rpm there is what sounds like a harmonic squeel...it comes in and drops off at the above rpms. the 3blade has never made that noise. Have any of you guys ever had a prop do that?
Enjoyed readin so far.
I gleened some good info from here so far.
boat= XP18 Xpress CC with the f70
WOT with 13 1/4 X 15 std 3blad alum 2 peps and 9 gals of gas trolling motor and 2 batteries (with stock tach) @ 6100rpm
Speed (avg up and down river with GPS) 35.8 MPH
Same load as above
WOT with Solas 13 X 15 4blade 6100rpm
Speed (same as above) 35.7mph
The rpm range of 3800 to 4300 saw the better improvment in speeds...not to much but a 2.5 mph increase in the 4300rpm range is ok with me since thats the range I usally run in most of the time.
Speed with the 3blade was 24mph @ 4300 turns
Speed with the 4blade as 26.5 @ 4300
Hole shot was/is impressive with the stock 3blade....maybe its a bit better with the 4blade but not really night and day difference. It almost jumps on plane in the lenth of the boat. I think the transom is riding higher and that's lending a bit more measureable speed on the midrange rpms.
the only quirky thing is this....@ 1200rpm to 1400rpm there is what sounds like a harmonic squeel...it comes in and drops off at the above rpms. the 3blade has never made that noise. Have any of you guys ever had a prop do that?
Enjoyed readin so far.
I gleened some good info from here so far.