Ran for the first time

[evin268fs]

1998 Stratos 268 FS with 115 Intruder, 60 degree block
Ran 42.8-43.5 consistant, GPS, 14 x17 Viper prop RPM Guage did not work, showed 4500 rpm, but I had to be turning close to 6000 or more to get that speed I think? Any guesses what type of RPMS I am spinning,

Holeshot is great, can sacrifice a little here. Could trim all the way out, without blowing out or losing speed, still gaining in fact. Looks like there are some trim extenders on it already, two flat washers on top on the pistons??

No jackplate, Water Pressure 20 PSI at WOT. drops to 10 when not WOT, under 5 at idel speeds. Can I see 4 or 5 more mph?
I know enough holeshot to pull skiers will not be seen with a 20 raker, best speed choice. I guess the question is will I see better holeshot with a 14 x 19 Viper/SSTor 13 x 18 Raker.
I plan on raising the motor one hole since I can trim all the way out. Is this a good idea on a fish and ski??

Sorry for the long post.

 

[Silvertip]

Re: Ran for the first time

Until you get an accurate tach don't spend money on a prop. You are guessing at 6000 RPM and at that rpm the prop calculator shows 16% slip so your guess is wrong, the tach is wrong, or both. Make sure the tach calibration dial on the back of the tach is set to 6 pulse.

 

[evin268fs]

Re: Ran for the first time

I used a prop calculator and used this reasoning to guess at 6000, 2 gear ratio GPS 43, 17 Pitch and rpms of 4500 unknown, calculate, said speed not possible -18 % slip not possible. So I put in a reasonable slip 15%, prop pitch 17, GPS speed , and it gave me an estimated rpms of 6250, put in 10% slip and computed 5939 rpms, I am assuming slip is somwhere between 10 and 15% for a fish and ski boat. So the rpms should be between

Does this make any sense at all??