16 foot tri hull what motor can I run for best results

[BrianPalm94]

Hey everyone I'm new to this site and just got my first boat. I Live in Colorado so the altitude plays a big roll since it limits the horsepower output on are boats. I have a 16ft tri hull with an 80hp mercury thunderbolt outboard. The plac in the boat says the transom is rated for a motor up to 175hp and I want to know what all you guys would recommend to run on this boat. I want to use the boat to mainly wake board and slalom ski and it will mainly be hitting lakes between 7,500 and 10,000 feet all the help I can get is appreciated thanks.

 

[SkiDad]

I'd want around 150hp. That way you would have the equivalent of 115 HP. I would think it would be hard to get up on slalom on 80 at that altitude. Might be cheaper to get something different boat wise. Make sure transom is sound if you repower

 

[metriccrescentwrench]

Yep, I'd think at least a 150 if not a 175. IMO an 80 on a boat rated for 175 is pretty marginal even at lower altitudes.

Whatever you decide to get I'd suggest looking into what the engine manufacturer recommends for high altitude operation.

 

[BrianPalm94]

right on guys thanks for the help. I do plan to look at redoing the transom. the boat was a freebee from someone in town. the floor was rotted so i just stripped the interior out of the boat and cut the floor out. it was a pretty nasty mess so before i put a new floor in i am separating the hull and the cap, and plan to replace the transom reglass it and start putting it back together. I am planning to do a thread for this boat as well. one other question my cousin thinks I should go with a twostroke over a fourstroke to help me get out of the hole faster despite the smell and the noise of the twostroke which doesn't really bother me anyway, agree??? disagree????

 

[skibrain]

I've owned a couple of 16' boats and I would be EXTREMELY surprised if you trihull is rated for a 175 hp outboard. 90 or maybe 120 hp is more typical. A new supercharged Mercury Verado would minimize power loss at altitude, but I don't suppose you are planning to spend $15k on a motor. I would recommend lower hp (your 80 might be fine) or a 115 2-stroke, but pay attention to prop selection. For skiing you need a boat that will go 35 mph so you could run a 17 or 15" pitch ( think lower gear in car) for the hole shot you need. Might need to watch wide open rpm without a load, but that should get you there, and is a much cheaper experiment.

 

[inthedirtagain]

At that altitude, bigger is better.