Good evening all,
After reading this forum for many months, and coming back to this forum everytime I have a question about something I've finally need to ask something specific. Is my 140 really that gutless? I have a 18' 1979 Chaparral with 140 mercruiser. My latest prop is a 14.5"x18 4 blade(at the recommendation of the local prop shop). Since this is my first 4 cylinder boat I have been around/on, I'm not sure whether this boat should be this gutless. The hole shot seems slow, about 30+ seconds to get up on plane, and about another minute to reach my top speed of 28 when I trim right (with only 2 adults in the boat). At that speed I'm not even achieving WOT, I'm only hitting about 3500. I had a 14.25x21 3 blade prop on and hit 32mph and 3800 rpm, but the hole shot was slower. Last year when I got the boat it had a 15 x 17 prop. Top speed was 23, but WOT rpm was about 4300, and hole shot was much better, fairly quick to plane. I just rebuilt the carb this spring and everything seems to be operating normally. So are the numbers I'm seeing with the different props normal, or is there something else I'm missing? I've read forums that say their 3.0's are getting upwards of 40 mph and can pull tubes and stuff no problem. Any advice is greatly appreciated, thank you.
After reading this forum for many months, and coming back to this forum everytime I have a question about something I've finally need to ask something specific. Is my 140 really that gutless? I have a 18' 1979 Chaparral with 140 mercruiser. My latest prop is a 14.5"x18 4 blade(at the recommendation of the local prop shop). Since this is my first 4 cylinder boat I have been around/on, I'm not sure whether this boat should be this gutless. The hole shot seems slow, about 30+ seconds to get up on plane, and about another minute to reach my top speed of 28 when I trim right (with only 2 adults in the boat). At that speed I'm not even achieving WOT, I'm only hitting about 3500. I had a 14.25x21 3 blade prop on and hit 32mph and 3800 rpm, but the hole shot was slower. Last year when I got the boat it had a 15 x 17 prop. Top speed was 23, but WOT rpm was about 4300, and hole shot was much better, fairly quick to plane. I just rebuilt the carb this spring and everything seems to be operating normally. So are the numbers I'm seeing with the different props normal, or is there something else I'm missing? I've read forums that say their 3.0's are getting upwards of 40 mph and can pull tubes and stuff no problem. Any advice is greatly appreciated, thank you.