I have a crawdad jon boat with a 30lb trolling motor.

Would like to get a second motor with more power for bigger waters. Its rated up to 5 hp outboard. A gas powered outboard new is $850 and up. How does the lbs of thrust convert to hp? Instead of getting a gas powered outboard, I'm thinkin if i got the biggest electric trolling motor (55 lb thrust), how much hp is that?

A good electric motor is about $200 + battery.

I doubt a 55 pound thrust electric motor produces anything near one horsepower.

My opinion is to get a gas motor to use for longer runs, then use the trolling motor for fishing.

I have a 55 pound thrust MinnKota for my square stern canoe. Even with the larger size deep cycle batteries, running from here to there on high speed during normal fishing will wear the battery down in five or six hours.

When I fish smaller ponds, and rarely use it on high speed, the battery still has plenty of juice after a day's fishing. Could probably get a couple of days fishing using it like that.

The five hp gas outboard will move your jon a lot faster than a 55# trolling motor. Unless you do an inordinate amount of running around, you won't use a gallon of gasoline in the outboard per day of fishing.

It takes 90 lbs thrust to equal 1 hp, or so I was told by my boat mechanic. I'd stick a gas motor on there as well as the trolling motor, like Rhino said.

If you are looking for more power, you need to step up to a 24v or a 36v system.  I have a 36V motorguide with three batteries.  That thing is an animal and after having the 36v tm, I am never going back to anything smaller.  For that matter, I wish someone would make a 36V / 48V TM.  Maybe the TM could be 36V all the time with a 48V bypass when you needed a little extra juice. 

Check into the 24V systems.  It will be well worth the money.

746 watts equals 1 horsepower.

Thanks guys,

Well, after reading everyone response. I'll stick with the gas motor.

For a crawdad boat that's rated up to 5 hp. What's the smallest motor I should get? I've been looking on C-list for a used outboard. Found some from 1.5-5 hp. For cheap money too. What brand is the most reliable?

If you can afford a 5hp, get a 5hp. Nissan/Tohatsu makes a decent small motor. 4stroke would probably be a good choice.

It takes 90 lbs thrust to equal 1 hp, or so I was told by my boat mechanic. I'd stick a gas motor on there as well as the trolling motor, like Rhino said.

That is true when using a static test. If using an actual thrust test is closer to 133 foot pounds.

Chad

Thrust and horsepower are not directly related and therefore not easily converted.  Here is a link that explains how to convert them.

http://www.aerospaceweb.org/question/propulsion/q0195.shtml

Thanks guys,

Well, after reading everyone response. I'll stick with the gas motor.

For a crawdad boat that's rated up to 5 hp. What's the smallest motor I should get? I've been looking on C-list for a used outboard. Found some from 1.5-5 hp. For cheap money too. What brand is the most reliable?

i just bought a 2003 3.3hp 2-stroke mercury that was used about 2 times for 400 yesterday. if you wait, you can find the deals. try and get a recent one. im really excited to use mine and i have a pelican bass raider

I was thinking like you a few years ago. I had a 30# TM on my 10' jon and wanted more speed. I got a 55# TM and it did not go any faster. Was told they all run about the same speed it's the torque/ push you get in current and wind the goes up with the Lbs. I now run a 1956 Evinrude Lightwin 3 hp, with a 1 gal. internal tank and I love it. It's a perfct match for my small jon, just fast enough and still safe and easy to handle.