See full version: 90 hp Top Speed
In my experience, other than failure to do basic maintenance, the leading cause of engine lifespan is asking it to do too much. A boat should be proped properly for wot rpm range, after that wot should be used only for short times. Stay within the cruising range and you will get longer life out of all the parts.
SS props cause a lot of failure up where I live. Hit a rock or stump and now you are replacing lowers and vertical shafts in stead of props and hubs. more
its obvious when you move up too much.
Adjusting height may help or it may just cause the prop to pull air as soon as you get up on plane. Then it will almost immediately have the engine rev up and top speed will go down. here
Just my 2 cents from a guy who has seen several people repower after trying to get an extra MPH or two out of a perfectly fine motor. I doubt there are many people that dont have extensive performance boating/race experience that can tell the difference between 42 and 43 without looking at a gauge.
Re: Speed with a 90hp on pontoon
Re: Speed with a 90hp on pontoon
proper propping and height of that motors is what is going to make the biggest difference. here
thanks for the replies, i will defintely prop it out right, it is a two stroke, i am going to try to get it around 5500-6000 rpms.
I have a 25' Crest Savanna model - big heavy girl. I typically top out in the low 20s, but with no one but me on it, less than half a tank of gas and virtually no gear, I can make her go 26 or 27. Just make sure you prop it right so you can get the correct RPMs at WOT. Took me 2 tries to get mine dialed in, but she's great now, even with 12 people on her!
Re: Speed with a 90hp on pontoon here
20'er with a 90 Merc. 4 stroke. Only myself onboard.
As suggested 27 or so mph.Keep in mind you'll be using about 9 Gallons par hour(gph) at wot.(wide open throttle)instead of the 4 gph of your 40.
Of course you can throttle back to save gas and your 90 will be loafing instead of running its guts out like the 40.Be sure to get it propped right. here
thanks for the replies, i will defintely prop it out right, it is a two stroke, i am going to try to get it around 5500-6000 rpms. [links]
Re: Speed with a 90hp on pontoon
Okay, we're finally going to get a bigger motor for our 21' Suntracker Fishin' Barge. With our 60hp Mercury Bigfoot, top speed is 17.5 mph at 5,000 RPMs. So we NEVER go more than 11 mph and that's at 3,800 rpms. No joy.
Here's the motor we're considering, but I didn't want to make a move until I heard from you all. Your words of wisdom have saved me many times from doing stupid things here
Need your opinions- is 90hp going to provide any significant difference in boat speed? Lower RPMs? Anybody else here running around with 90 hp? [links]
2016 Mercury 90 HP EFI 4 stroke
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It can be measured in mpg. If you're talking modern outboards, ie: direct injection 2-strokes or 4 strokes on a party barge, you should be looking to get +/- 5 mpg for 90-115. 150 - 200hp -4 mpg. I'm averaging +/- 3 mpg. I'm sure others will chime in but reading through many boat tests on Party barges, thats a pretty good ball park. Good luck . more
I'm sorry, but it would take a 115 hp motor to pull a skier, and even then the speed would be very marginal @ about 25 mph. [links]
If you are going to spend a lot of money on the boat you mentioned and expect to ski adults behind it, I think you’re going to be disappointed unless they can prove to you it will run around 30 mph or better. more
Re: 90HP Pontoon Pull a Skier?
My new Bennington tritoon w/strakes and a F150 Yamaha is good for 40 mph on top end.