Need a really slow cart

[fsubob]

I am building a cart for my 3yo because I am tired of having to mess with the power wheels batteries all the time...

I am looking at buying a little one seater with a new 6.5 hp harbor freight engine for $150. I know the engine is really to big for a 3yo first cart but I was wondering if I could limit it to only go a max of 5mph...

I have never built a cart before so I am not sure if this can be done. I assume the throttle could be limited some how by lengthening it or putting a stop under the pedal to keep it from being depressed to much? I am willing to change tires gears etc to make this happen...

Any ideas? Its such a good deal I am willing to buy it even if I can;t slow it down for her right now and Dad will just ride it until she gets older

 

[old pat]

suggest putting her in a booster seat safer and help her see over the wheel, i just tightened the screw on the throttle control on the motor so they can only go so fast
i attached some blocks the gas petal so the kids cpuld reach them and yes youcan reduce the gear ratio so its slow (learned that here this is really a good forum)
i have some great grand kids 3 and 5 so i put a leash on about 100 feet of real strong fishing line to a kill switch ( ive got 5 acres so they get away quick)

 

[old pat]

hey i fixed one for my grand son i put phony petals in so they thought they were making it go then just adjusted the throttle at and idle if they crashed (which they did, no damage)

 

[MacfarlaneRacers]

Just Get Him A Pedal And wait till hes about 5 and start building one. Hes 3. He's just started speaking !!!

 

[fsubob]

My kid has been speaking well for over a year ahaha!!

Got first power wheel mini quad at 1 yr old and had 3 large ones since then... Drives really good just don't want to go to fast for safety...

a long cable on the kill switch sounds like a good idea and I will check out the throttle screw to see what that does...

Thanks for the ideas and it you have any others please speak up... I know 3 yo is young but I started early as well. had my first minibike at 4

 

[bighead]

Here is my slede style kill switch. Just hook a longer string to it. Also my throttle stop.

Gearing it really low will be your best bet.

 

[fsubob]

Thanks where did you buy that kill switch from looks like thats the ticket!!

Also to gear it low what would you suggest? I was going to try and put tires about the size of golf cart size hoping to get alot of clearance for a really large sprocket hoping that between the tires being really heavy and the sprocket large it would add the the slowness... sorry my first kart build so my terminology and understanding of the gearing to size of motor/tire is minimal.

 

[r97]

you can limit your throttle, but only to a point because the clutch will not lock properly at lower rpm which wears the clutch. that is unless you have a torque converter, then you can limit it low.
your other option is gearing, making the tires larger will make the kart a bit more unstable, have less power, and will make it go faster, so larger tires would require an even larger sprocket. if you were to gear down the kart, a jack shaft would be needed. the only problem with gearing a 6.5 to 5mph is that it will have monster torque which you might not want.
your best option is probably to just get a smaller engine, you could find a used briggs 3.5hp, or look into a harbor freight 2.5hp engine which unmodified and geared low would work nicely.
one other option would be to gear the 6.5 pretty low, then limit the throttle and use a belt tensioner clutch which would work fine at a lower rpm.

i think this is the type of switch you should be looking into,
http://www.amazon.com/Safety-Kill-Switch-Switch-Magneto/dp/B002MBOZP6

 

[fsubob]

Thanks for the info...

sounds like getting a smaller engine is the only way to go since I do have have a lot of access to welders and the like...

I will ride around on the 6.5hp for a while before getting the 2.5hp from Harbor Freight. I might even be able to trade someone on craigs list for a smaller engine.

Thanks for the link to the kill switch!

 

[r_chez_08]

Hi,
personally, if you are getting it for $150, i would get a 6:1 gear box or similar and then gear it from there. then you wouldnt burn the clutch, and no throttle stop would be required.
Alternatively you could achieve a similar affect with a jackshaft, by creating a gear ratio, for example, of 6:1 with a 10t cent. clutch and 60t sprocket, and then gear it from there onto the axle.
Just my 2p
Rob

 

[Kaptain Krunch]

everyone seems to have good ideas, but heres my 2 cents.

Get an old riding lawnmower, and modify it to accomodate a little person (pedal extensions, better seat with harness). that way you could just leave it at idle, put it in first and let him (her?) control the clutch to stop/go.

I drove riding mowers till i was about 10 because my dad wouldnt buy me a go kart, nor let me spend my own money on a go kart, it was fun for sure.

 

[Doc Sprocket]

I have to disagree with an above opinion- I don't think it's worth your effort to get a smaller engine. ALL these industrial engines are mechanically governed to the same RPM. Secondly, as low as you'd have to gear it to top out at such a low speed, the 2.5 hp engine will push the same as the 6.5. Reducing the engine's net HP will do nothing for you. In this circumstance, speed is a matter of gearing and max RPM, nothing else.

Finally, as the kid grows and you regear to meet his ever-increasing need for speed, this is where the net HP comes in. Geared a lot higher, the 6.5 will be able to push him along long after the 2.5 runs out of steam.

Regarding gearing, smaller tires are key. With a projected max 5mph, there's is NO tire combination that will help the sprocket situation. You WILL have to run a jackshaft for compound gear reduction. You may have to run two of them.

BTW- the riding mower is a very functional concept- It's what I did for my kids to fill the gap between their DeWalt-powered Power Wheels, and the go kart.

 

[bighead]

Thanks where did you buy that kill switch from looks like thats the ticket!!

Also to gear it low what would you suggest? I was going to try and put tires about the size of golf cart size hoping to get alot of clearance for a really large sprocket hoping that between the tires being really heavy and the sprocket large it would add the the slowness... sorry my first kart build so my terminology and understanding of the gearing to size of motor/tire is minimal.

The kill switch is common on Snowmobiles. I just Ebay Snowmobile/Tether kill Switch. Then looked for the bet deal. I got that one for like $5 plus $7 shipping.

Also there is threads here about remote kill switches. But I think it was lost in the site crash. Basicaly using a fob or RC controller to kill the engine.

 

[Lynx_Genisys]

i would weld on a bracket behind the pedal with a nut on it... or a nut onto side of pedal so it hits the frame/chassis..

set it up so a bolt goes into the nut, and hits a stop, so essentialy you can only press the pedal so far, limiting the speed...

I have a 6 yr old who for sum ungodly reason aims for bushes and plows on forward.. be it quad, pedal bike, or gokart.. for better or worse.. this is the only idea i have to save him from himself!!! lol

 

[old pat]

actually you can get the bolt on parts for a remote kill switch from radio shack or other electronic store for remote control robot or rc cars and trucks my son called and told me about it i think some of the imported quads have one on them

 

[old pat]

just googled remote kill switch several companies out there make them looks like they run 50 bucks and up try 3Build LLc.com

 

[MacfarlaneRacers]

Well The Advantage is when he gets older you can un-restrict it.

 

[fsubob]

Thanks for all the posts... will let yall know how it works out.

 

[MacfarlaneRacers]

Hope Everything goes okay !!!

 

[MatthewBasaraba]

Did that guy's post how he made the power wheels into a gas powered gone from the Crash? That would be an AWESOME upgrade from the electric...

Matthew