@hp Honda or 38lb electric motor

[Guest]

OK, I have reviewed all the past discussions where some of you feel having any kind of motor on the transom of a Daysailor is a sin. Others say if you must have some kind of motor and you should only use an electric, while still others say a gas engine is the only way to go and the biger the better.
My story, a very narrow straight channel used by power boats one sail boat (power boaters very impatient if caught behind me). When the wind is right (90% of the time) I, of course, sail out and after a wonderful day on the water, will sail back in. From time to time, I am one of those who must have power or I can not get down the very narrow channel. With the wake from the power boats, the wind, the tide and the width of the channel, I can not tack upwind nor can I row the boat. I have been using an electric motor but must admit hulling the 60lb battery around is a royal pain. I have been thinking about purchasing a Honda 2hp 4 stroke engine to stow in the front of the boat (where I keep the battery and electric motor) as it only weights 28lbs and runs on straight gas.
My question, as someone that knows very little about boat motors, does a 2hp gas motor have the same pushing power as a 38lb electric motor? Yes, I know a 5hp has more that an electric motor but I do not need a large motor. So without a lecture about pure sailing ability, which I will be willing to bet we all have, can anyone answer my simple question.

Jerry (hobie16-at-yahoo.com)

[Guest]

Not sure about the ratings, but I use a 2 HP Honda 4 stroke long shaft, the air cooled engine, on my '68 Daysailer in Casco Bay Maine. Engine works great. Pushes me right along against 1-3 knot tidal currents without any trouble. I think the longer shaft is the right choice. The dealer told me that at lower rpms, the 2 HP four stroke is equivalent to a 2 stroke 4HP engine. Not sure of the physics here but the 2 HP is plenty for my daysailer.

Hope this helps.
Doug.

Doug MacPherson (dwmacpherson2000-at-yahoo.com)

[Roger]

I checked a NASA site and they indicate that the conversion is 1 HP is 550 lb-ft/sec. , but I suspect the latter is different than pounds thrust. I suspect that that conversion we are thinkig about is 1 hp to 9.21 pounds thrust. 2 hp would therefore be 18 pounds, 3 hp =28 etc. I had a 28 pound thrust electric and would agree that it acted like a 3 hp on my canoe.

[Roger]

I correct myself! I found this and copied it from another site after noting numerous warning about comparng hp and pounds thrust...

"There is no relationship between thrust and hp, but you can calculate hp based on voltage and amp draw.

(Voltage * Amps Draw / 764) * 80% = output hp

The 80% reflects that some energy is lost due to resistance and friction in the emotor and control system.

A 74lb 24v trolling motor will draw about 38amps max. This puts the hp output at about 1hp.

A 100lb 36v trolling motor will draw about 35amps max. This puts the hp output at about 1.25hp

However, I would assume that you really want to know how fast your boat will go with an electric as compaired to your gas motor.

The answer is simple, your boat will go no faster than about 4mph with a trolling motor unless you try aftermarket props. You should select the smallest thrust motor that will reach 4mph which would be the 74lb 24v motor in my opinion. A pair of Trojan SCS225 batteries would be a good choice for the power supply."

end quote

[Guest]

I had a 38 lb electric and I too got pushed around by the tide/wake/pushy stinkpot thing. So I upped to a 3.5 hp tohatsu, and love it. The peace of mind that, WHEN NEEDED, I can scoot under the drawbridge in a hurry or overcome a tide when I've stayed out a bit too long is well worth the price. It weighs all of 30 lbs, stays on the transom, and never gives me worry about a battery charge. My only regret: not getting the long shaft. In a chop with my crew up on the bow pulling in the jib it capitates.

Tom (dmbeames-at-comcast.net)

[Guest]

Thanks Roger and Doug for the good information. It will assist me in making a decision this spring.
Do I stay with electric or go for the gas?
Another question-----When I have used the electric motor with the 50lb plus battery, once out of the channel I remove the motor and stow it and the battery forward so it is out of the way. No problem storing an electric motor on its side but how about a gas motor? Will the Honda 2hp 4 stroke leak if placed on ist side?
jerry

jerry (hobie16-at-yahoo.com)

[Guest]

Forgot two things...don't expect the 4 stroke to be quieter than the 2 stroke, or smoother. The engines are just too small to make a difference, and you'll save a few Benjamins going with the 2 stroke. I only mix the oil and gas once or twice a year with a 2 gallon jug; after 2 years no problems at all. And, a nice feature of the bigger motor (3.5 vs 2 hp) is that the 3.5 has a neutral gear; the 2 didn't.

Tom (dmbeames-at-comcast.net)

[Guest]

The motors take up less room when placed "prop up" as opposed to on their sides, which is I think how they're designed to be stored. But as I said earlier, I keep mine on the transom in the trimmed up position.

tom (dmbeames-at-comcast.net)

[Guest]

Tom is right. Don't expect the 2HP Honda to be quieter. It is however lighter. Additionally, the Honda 4 stroke has a "friction" gear which engages when you apply throttle. Thus, there is no separate gear shift lever. To go in reverse, you rotate the prop 180 degrees. Hope this helps. I have had the motor on it's side and it did not leak.
I haven't done this a lot however, I leave mine locked to the transom of the daysailer.

Cheers,

Doug.

Doug

Doug MacPherson (dwmacpherson2000-at-yahoo.com)

[Guest]

The 2hp honda is designed to be stored on one side only,with handle side up. If gas is turned off and air vent it will not leak. Forget about the 2 stroke,even though both 2&4 stroke 2hp's only take a quarter gallon to fill up the 4 stroke will run much longer and further on that little amount of gas.

A electric motor,s battery alone weighs more than a filled up 2hp honda and will run out of juice before the honda runs out of gas.

Tim (t1donnelly-at-shaw.ca)