What is the lowest hp?

[Thedude]

What do you think the lowest hp that can still move a go kart is?

 

[Kaptain Krunch]

You could move a go kart with less than a hp no problem. Not very fast though.

 

[Doc Sprocket]

Bit of an obscure question. Suppose you tell us what you want to acheive, and we'll throw our hats in. Example- If your cart is 14" long and weighs 5lbs, and will be driven by a very talented squirrell, you'll have no problems with 1/4 hp. If it outweighs my Durango, good luck to you, shop for a V10 Viper engine.

 

[Thedude]

With me on it it ways about 200.

 

[solomon]

5hp should be a minimum

 

[Doc Sprocket]

Yeah, I'd stay 5 and up. A lot depends on desired speed, tire size, frame size and weight, intended use, etc., but 5's a good start.
Got pics?

 

[Kenny_McCormic]

Just use the biggest baddest engine you can afford, you will thank me later.

 

[THE HUNTER]

technically speaking, any size engine would move a kart.... but of course it might be at a VERY slow speed lol.

 

[KieranM]

i have seen the harbour freight 2 and a half engines having good pulling power on a kart, but its not as simple as you think, gear ratios play a vital part with a lower power engine on a kart, as they do with any engine.

 

[robbie]

Ditto on the Harbor Freight 2.5 hp. I bought an el-cheapo go kart with one wheel drive and a Briggs 5 hp. I got tired of messing with the carburetor on that one, so I put a 2.5 harbor freight engine on there with a jackshaft and somewhere around 2:1 reduction. It peels out, does donuts, and goes about 15 mph, which is plenty for farm and driveway running. It even pulls me around at 225 pounds, although it doesn't do donuts very well.

If you're racing and you want top speed, you'll want something bigger.

 

[robbie]

Just to be clear, our go kart already had 11 teeth in front and 54 in back. Then I added the jackshaft with 17 to 9 when I switched to the 2.5 hp engine. My kids spent a week driving the hell out of it until it ate a wheel bearing, so you could say that it's plenty entertaining.

 

[Doc Sprocket]

Okay, so you new ratio is 9.8:1, thanks for clarifying.

 

[Blazkowiez]

Why do you want to go to a lower horsepower?

If the answer to that question is "because this kart is for a small kid and I don't want it to be fast" understand that you are working with small 4 stroke engines, they all technically have the same top speed.

Horsepower mostly will determine the torque and how easily they get up to that speed, certain things like gearing or transference of torque can determine your speed as well but these terms mean nothing unless we know why you want a small engine? Do you have weed eaters laying around doing nothing?

 

[Thedude]

That makes sense. 1 weed eater, 2 chainsaws, 1 lawnmower (that I'm about to turn into a horizontal engine), and an 8hp briggs welder motor.

 

[robbie]

Why do you want to go to a lower horsepower?

If the answer to that question is "because this kart is for a small kid and I don't want it to be fast" understand that you are working with small 4 stroke engines, they all technically have the same top speed.

Yeah, that's true. I geared the linkage slower and went to a smaller engine, but I suppose I could have done the same thing and switched over to a 10 or 12 hp engine and had virtually the same performance. The top speed would remain the same, and the wheel already peels out and slings dirt with a 2.5 hp engine, so the same thing would happen with a big engine. It would just make more noise and eat more fuel doing it. You could go either way, but it just looks funny to gear a go kart down for inexperienced kids and keep a big engine on it.