Siegmund
21.04.2021 4:31:43
28 -- maybe 30 on a good day. But it all depends on state of tune, health of the engine, condition of the hull and load.
See full version: Top speed from a 40hp 2 stroke yamaha
28 -- maybe 30 on a good day. But it all depends on state of tune, health of the engine, condition of the hull and load.
33 to 36 mph. Depends on number of people. gear ,beam of boat,where controls are and if is trimmed out. Nothing in it, all weight including you towards the stern you might get a few more mph, just a guess.
Re: top speed from a 40hp 2 stroke yamaha. [links]
Thanks again for the feedback.
The boat is a 1992 sea nymph tx155 with console and controls..with a max rating of 35HP. Is there any real warm in replacing the current johnson 28hp(weight approx 130lbs) with the Yamaha used 40hp(weight approx 187lbs)?? Any info would be greatly appreciated
Nick more
You should be pushing close to 40 mph, it depends on the diameter and pitch of your prop and wot rpms. I don't think its too much motor for that boat, it will handle it. [links]
28 -- maybe 30 on a good day. But it all depends on state of tune, health of the engine, condition of the hull and load.
Re: top speed from a 40hp 2 stroke yamaha.
Pontoon Type Pontoon Length Top Speed
————————- ————– ———
South Bay Super Sport 925 27 feet 57 mph
Manitou 25 X-Plode XT SHP 26 feet 62 mph
Harris Crowne SL 250 27 feet 63 mph
PlayCraft X-Treme 3110 31 feet 65 mph
How do high-speed pontoons work? Most high-speed pontoons run on triple logs (hence the name tri-toon) but in this case, a pair of logs was designed to trap air in-between the pontoons and utilize it to create lift. In both theory and practice, it works much like a modern powercat. The design also saves weight and reduces wetted surface.
A: Although you could pull tubes with just about any size outboard, to be safe you would need at least a 90hp engine to satisfy the tubers in your family. The ideal engine would be a 115hp or 150hp engine if your family is big into water sports. more
I would monitor the timing while the problem shows up to see it that is changing.
Seems like something in the carb bowl could move around and cover the main jet restricting fuel to a cylinder under those conditions. Once you shut it down it could float off the jet.
Something to look for is all else is good.
If the needle does not seat/close off in the enrichment system then the extra fuel will go to all cylinders,
But if a hole develops in diaphragm the fuel could be sucked into the pulse port maybe. Fuel pump could do this also
I do not see this happens and then going away though more