Too much HP?

[Beefer]

I have an old Johnson 10hp (1959 QD-20), and am going this afternoon to look at an Achilles inflatable that is about 8', 4 person (sounds crowded), 845lbs capacity. Will this be too much for the boat, or will it be okay? Engine weighs (I think) 70lbs or less.

This would be for my wife and daughter to tool around the canal bay out back.

 

[jacoboregon]

Re: Too much HP?

what model achilles?

the capacity plate should state the max rated hp.

 

[Beefer]

Re: Too much HP?

OK, I went ahead and got it. $40. Wood floors and transom, pump and oars. It's older, but it's the Achilles LTD-4. Says max HP is 6hp. I'm (eventually) going to go ahead with the 10.
It does have the transom, not like the new LT-4.

 

[lehkyc]

Re: Too much HP?

kinda late reply here, but you should be just fine with the 10hp on it. those small motors really dont add too much wait when they increase in power. i use to run a 9.9 merc on my brig inflatable rated for 6 hp, my 9.9 was a 4storke which helped keep the bow up in choppy water and multiple people.

 

[Beefer]

Re: Too much HP?

Actually, your reply is perfect in timing.

I just tonight rebuilt the fuel pump and got the motor running (hadn't worked on it until the other day), and was planing on trying it out on the dinghy this weekend. Thanks for the info!

 

[lehkyc]

Re: Too much HP?

no problem, your lucky you get to be on the water this weekend. have fun!

 

[Beefer]

Re: Too much HP?

Well, had the maiden voyage on the Achiles with the 10hp (See the story here).

All in all, it was fun, but I don't think I would let me wife and daughter take it out on their own. It was like a ride at Busch Gardens! It was cramped (I was alone), and the bow went way high before planing. It was kinda cool when it planed out, because you could feel it lift up in the stern, and I could also feel the chop in the flooring. I could see my wife now... By guessing, I think I got up to about 18mph, but I have no real idea (didn't bring the GPS). By the end of the ride, I was pretty wet. Are these things always such a wet ride? Had about 3 gals of water in there when I pulled her out after I got back. She'll make a nice tender for putt-putting around in, but I don't think I need the speed on this thing. Probab;y should move down to a 4-6hp, or even a trolling motor.

 

[lehkyc]

Re: Too much HP?

yea they are wet rides. even with a small motor, the bow will go way up before planing. theres just no weight up there to keep it down. some people store the gas tank in the bow which i suppose would help but even that probably isnt enough weight. try a hydrofoil. those help alot for keeping the boat more level at all speeds. mine with a 10hp went about 25 mph. very fun on a calm day but beat the hell out of you if there was chop.

 

[jrs_diesel]

Re: Too much HP?

I sometimes run my 1986 9.9 Johnson (2 stroke) on my Bombard Max 3, a 9' wood floor SIB. The boat is rated up to an 8 HP, but the 9.9 Johnson weighs less (72 lbs) than any modern 8 HP four stroke engine. I usually take it easy when I have that engine on so as not to over stress the transom. I have to say the hole shot is amazing the few times that I crank her wide open

Here's a video I took with my old phone last year of it: