Need help determining speed

[benton55]

I have a 96 Ski Nautique with the GT-40 351... the speedos weren't calibrated when I bought the bought so I've been skiing based on feel and RPM's. Can anyone tell me what the RPM's should be at about 35MPH? I've been running about 3500 RPM but not sure how close that really is. I need to get my hands on a hand held GPS or something to dial the boat in... Thanks!

[cmd]

are you running a 3 or 4 blade prop.also how much weight do you have in the boat.people,etc.i'll check next time out i'm out but if memory serves 3500 should be around in the upper thirties.

[benton55]

are you running a 3 or 4 blade prop.also how much weight do you have in the boat.people,etc.i'll check next time out i'm out but if memory serves 3500 should be around in the upper thirties.

Running a three blade prop. Typically just two people in the boat and no extra gear... skied today...3500 feels right but I'm still curious to know if this is fast or slow....let me know the next time your out. Thanks!

[Rick]

My 196 witha 4 bladed prop is 35 mph at 3500 rpm. If you have a course and no GPS you can time yourself through the course and calibrate your speedos that way.

[lztat573]

Just get a GPS it is a lot easier, then you know.