Franko Manini
Well-Known Member
Hey folks,
I've got a 20' Thunderjet Luxor (AKA the Falcon in Canada) that runs a Suzuki DF140. The current prop is the stock Suzuki 3 blade, 14" diameter, 21 pitch model. I'm happy with the boat's performance, but always looking to tweak it here and there. I was out a couple weeks ago and the water was flat and calm so I decided to do some WOT testing. Two guys and gear in the boat, we topped out at 40MPH, but just as we hit top speed, the motor hit the rev limiter. For those of you who have never bumped up against the rev limiter, it's pretty damn shocking. The computer cuts the ignition and it scared the crap outta me!
Normal operating range for this motor is specified to be 5600 - 6200 RPM. If I hit the rev limiter that means I was over 6200 RPM. During the test, I did see the tach just inch past 6000, and then WHAMO - rev limiter.
What does this tell me? Am I under propped? Do I move up in pitch, move from aluminum to stainless steel? 3 to 4 blade? The prop stuff is so friggin confusing.
This is a family fishing/exploring boat, and I rarely do any watersports with it. Thoughts?
I've got a 20' Thunderjet Luxor (AKA the Falcon in Canada) that runs a Suzuki DF140. The current prop is the stock Suzuki 3 blade, 14" diameter, 21 pitch model. I'm happy with the boat's performance, but always looking to tweak it here and there. I was out a couple weeks ago and the water was flat and calm so I decided to do some WOT testing. Two guys and gear in the boat, we topped out at 40MPH, but just as we hit top speed, the motor hit the rev limiter. For those of you who have never bumped up against the rev limiter, it's pretty damn shocking. The computer cuts the ignition and it scared the crap outta me!
Normal operating range for this motor is specified to be 5600 - 6200 RPM. If I hit the rev limiter that means I was over 6200 RPM. During the test, I did see the tach just inch past 6000, and then WHAMO - rev limiter.
What does this tell me? Am I under propped? Do I move up in pitch, move from aluminum to stainless steel? 3 to 4 blade? The prop stuff is so friggin confusing.
This is a family fishing/exploring boat, and I rarely do any watersports with it. Thoughts?