NicksterFL
Seaman
- Joined
- Oct 29, 2014
- Messages
- 61
Boat: 19' T-craft Runabout style
Engine: Mercruiser 3.0 (140hp)
Drive: Pre-Alpha (1.98 ratio)
Prop: 13-3/4 x 21
Here's the story. last month my drive was toast (long story) but water intrusion resulted in the lower unit failing. It was a pre-alpha upper and an alpha 1 lower unit. I bought an entire new(er) pre-alpha 1.98 ratio drive. installed and put the boat back in the water this past weekend.
By myself, the boat handled normally, maybe a little less throttle to get to cruise speed then I'm used to, etc. but when I had a load (family, etc) I noticed a significant decrease in performance. Slow to plane (30 to 45 seconds). Top end was very slow. 2500 RPM's max at about 25mph (gps) at WOT. The only thing that has changed is the drive. same prop as before.
with my old drive, i cruised at about 3200 RPM's going about 25-30 at 3/4 throttle. I could easily push over 30 mph and it still had some spunk at the top end of my throttle if I needed it.
Am I over propped now? should I go with a wider diameter and lower pitch? I'd prefer to be on plane at lower speed and have some power. we don't ski or pull tubes, but mostly fish and occasionally get into some choppy waters. so I'd want the power when i have a load.
Engine: Mercruiser 3.0 (140hp)
Drive: Pre-Alpha (1.98 ratio)
Prop: 13-3/4 x 21
Here's the story. last month my drive was toast (long story) but water intrusion resulted in the lower unit failing. It was a pre-alpha upper and an alpha 1 lower unit. I bought an entire new(er) pre-alpha 1.98 ratio drive. installed and put the boat back in the water this past weekend.
By myself, the boat handled normally, maybe a little less throttle to get to cruise speed then I'm used to, etc. but when I had a load (family, etc) I noticed a significant decrease in performance. Slow to plane (30 to 45 seconds). Top end was very slow. 2500 RPM's max at about 25mph (gps) at WOT. The only thing that has changed is the drive. same prop as before.
with my old drive, i cruised at about 3200 RPM's going about 25-30 at 3/4 throttle. I could easily push over 30 mph and it still had some spunk at the top end of my throttle if I needed it.
Am I over propped now? should I go with a wider diameter and lower pitch? I'd prefer to be on plane at lower speed and have some power. we don't ski or pull tubes, but mostly fish and occasionally get into some choppy waters. so I'd want the power when i have a load.