Buehlers Days Off Posted October 7 What is the top speed on a 256ssi with the 420hp volvo Quote Share this post Link to post Share on other sites
Wingnut Posted October 7 My Merc 425 has a best of 63, perfect conditions. W RPM SPEED GPH MPG 2150 17 6.7 2.537 2600 26 8.7 2.989 2650 26.8 9.5 2.821 2700 27 9.8 2.755 2750 28 10.2 2.745 2800 29 9.9 2.929 2850 30 9.9 3.03 2900 30.5 10.4 2.933 2950 31 10.4 2.981 3000 32 10.8 2.963 3050 33 11.4 2.895 3100 33 11.7 2.821 3150 34 11.5 2.957 3200 35 12 2.917 3250 36 12.6 2.857 3300 36.5 13 2.808 3400 37.7 14 2.693 3500 39 15 2.6 3550 40 15.5 2.581 3600 43 18 2.389 3700 46 21 2.19 3800 49 24 2.042 3900 53 27 1.963 4000 56 30 1.867 4500 57.3 33 1.736 4950 58.7 35.5 1.654 5000 59.9 37 1.619 Quote Share this post Link to post Share on other sites
jdsdls05 Posted October 7 I have a regular 8.1 best I have seen is 54 gps Quote Share this post Link to post Share on other sites
MonkeySeaII Posted October 8 I have the 375 hp Merc 496 Mag. Best I've seen is 56-57 GPS in perfect conditions. 53-54 is more typical though. Quote Share this post Link to post Share on other sites
Buehlers Days Off Posted October 8 Thanks will have to wait and see this weekend. Quote Share this post Link to post Share on other sites
Wingnut Posted October 8 13 minutes ago, Buehlers Days Off said: Thanks will have to wait and see this weekend. Just enough ripples to break the hull loose, mid-grade gas, high barometric pressure, and temperatures under 70 degrees. Empty waste, water, and low fuel level, single passenger, canvas down, windscreen and transom door open, and trim up as much as the bow will tolerate. Oh, and leave any extra gear on the dock. Only ever bounced mine off the rev-limiter one time and it was exactly that situation. Go for it. W Quote Share this post Link to post Share on other sites
Gumby Posted October 10 Buehlers Day Off! Sorry, can't help you with your top end question but just curious, did you once marine in Racine, WI? Quote Share this post Link to post Share on other sites
Buehlers Days Off Posted October 10 Yes ,we moved to Florida and bought a day boat. Quote Share this post Link to post Share on other sites
Denny Posted October 10 On 10/8/2019 at 8:22 AM, Wingnut said: Just enough ripples to break the hull loose, mid-grade gas, high barometric pressure, and temperatures under 70 degrees. Empty waste, water, and low fuel level, single passenger, canvas down, windscreen and transom door open, and trim up as much as the bow will tolerate. Oh, and leave any extra gear on the dock. Only ever bounced mine off the rev-limiter one time and it was exactly that situation. Go for it. W All that prep kind of reminds me of my prep back in the day when I would race someone with my 1968 15ft Mark Twain with a 110 hp. Merc.(that was the biggest motor they made back then, that they nick named the tower of power) She would do 48 mph. Back in 68 that was fast for the conventional boat, the only thing faster were the racing boats. Then they came out with a 135hp. There was a guy that had one on a 18ft Glasspar that I raced,while I was sitting on the motor well, hanging onto the motor, at 48mph, we were neck and neck, that was back in my fearless days, how dumb was that. Denny. Quote Share this post Link to post Share on other sites
BajaDriver Posted October 10 On 10/7/2019 at 8:42 AM, Wingnut said: My Merc 425 has a best of 63, perfect conditions. W RPM SPEED GPH MPG 2150 17 6.7 2.537 2600 26 8.7 2.989 2650 26.8 9.5 2.821 2700 27 9.8 2.755 2750 28 10.2 2.745 2800 29 9.9 2.929 2850 30 9.9 3.03 2900 30.5 10.4 2.933 2950 31 10.4 2.981 3000 32 10.8 2.963 3050 33 11.4 2.895 3100 33 11.7 2.821 3150 34 11.5 2.957 3200 35 12 2.917 3250 36 12.6 2.857 3300 36.5 13 2.808 3400 37.7 14 2.693 3500 39 15 2.6 3550 40 15.5 2.581 3600 43 18 2.389 3700 46 21 2.19 3800 49 24 2.042 3900 53 27 1.963 4000 56 30 1.867 4500 57.3 33 1.736 4950 58.7 35.5 1.654 5000 59.9 37 1.619 What pitch prop are you using? Quote Share this post Link to post Share on other sites
Wingnut Posted October 10 17 minutes ago, BajaDriver said: What pitch prop are you using? Rear 48-823666 24P 14.25 Front 48-823665 24P 15.5 Bravo III-X with optional 1.81 final drive ratio Quote Share this post Link to post Share on other sites
BajaDriver Posted October 11 On 10/10/2019 at 7:05 AM, Denny said: All that prep kind of reminds me of my prep back in the day when I would race someone with my 1968 15ft Mark Twain with a 110 hp. Merc.(that was the biggest motor they made back then, that they nick named the tower of power) She would do 48 mph. Back in 68 that was fast for the conventional boat, the only thing faster were the racing boats. Then they came out with a 135hp. There was a guy that had one on a 18ft Glasspar that I raced,while I was sitting on the motor well, hanging onto the motor, at 48mph, we were neck and neck, that was back in my fearless days, how dumb was that. Denny. Awesome story! Quote Share this post Link to post Share on other sites
Denny Posted October 11 7 hours ago, BajaDriver said: Thanks, Denny. Quote Share this post Link to post Share on other sites
