Sprocket size help, small motor

[ML-TOYS]

I am setting up a small cart for a 6 year old.
They gave me a 2.5 hp motor to put on it. I got an 11 tooth clutch and it will have 13 inch tall tires in back.
What tooth count sprocket would be suitable for this setup.
It can have medium take off with good top end. I am putting an adjustable pedal stop to restrict top end until he gets used to driving, this way they can gradually increase the pedal for more speed.

I ask because i dont know the rpm of the motor to check charts for speed.

 

[Jake.B]

What brand is the motor? We can probably help you with the rpm range.

 

[ML-TOYS]

What brand is the motor? We can probably help you with the rpm range.

I will take a look in the morning

 

[Jcotz]

Just a suggestion, if you are running it with a centrifugal clutch, then it may be wiser just to gear it lower instead of putting a throttle stop. The throttle stop will prevent the engine from reaching higher rpm's (obviously) and probably won't allow the clutch to engage fully. This may lead to slipping and wear.

 

[landuse]

Just a suggestion, if you are running it with a centrifugal clutch, then it may be wiser just to gear it lower instead of putting a throttle stop. The throttle stop will prevent the engine from reaching higher rpm's (obviously) and probably won't allow the clutch to engage fully. This may lead to slipping and wear.

I agree totally with this comment. Throttle/pedal stops shouldn't ever be used.

I would gear it to around 6:1 (which is generally the norm). This means you will need a rear sprocket of either 60 or 72. Something inbetween would be better, but I m not too sure what tooth counts you get

 

[ML-TOYS]

I see what you are saying about the throttle stop.
The motor is a briggs & stratton.

 

[Rebel1]

I would do a 72 on the sprocket with that tire. The overall lower ratio would help get it going easier with a small motor and that tire size.

 

[OzFab]

I would do a 72 on the sprocket with that tire. The overall lower ratio would help get it going easier with a small motor and that tire size.

BUT, this will still give you a highish top speed. For a 6yo I would suggest a jackshaft as well. Engineered correctly, the jackshaft can be removed later when he/she gets a bit more confident/comfortable

 

[landuse]

I would do a 72 on the sprocket with that tire. The overall lower ratio would help get it going easier with a small motor and that tire size.

BUT, this will still give you a highish top speed. For a 6yo I would suggest a jackshaft as well. Engineered correctly, the jackshaft can be removed later when he/she gets a bit more confident/comfortable

It sounds like we are all rehashing what has been said. The OP now has to use the info we have provided, and make a decision on what he wants

 

[ML-TOYS]

Thanks i have been reading all replies. I put a 68 tooth sprocket that i had here and it seems ok, we shall see during the test drive.

I also want to put in a remote kill switch maybe bu using all my rc parts like a servo and micro switch.
I looked at some on ebay but most kills work on 12v and i dont want to mount a 12v battery on this.
Any other options out there?

 

[landuse]

Thanks i have been reading all replies. I put a 68 tooth sprocket that i had here and it seems ok, we shall see during the test drive.

I also want to put in a remote kill switch maybe bu using all my rc parts like a servo and micro switch.
I looked at some on ebay but most kills work on 12v and i dont want to mount a 12v battery on this.
Any other options out there?

Let us know how the sprocket works for you.

When you say a remote kill switch, do you mean one that is not connected by any wires?

 

[ML-TOYS]

A remote kill switch that a parent can shut the motor down. Like a remote for a car that opens locks

 

[landuse]

A remote kill switch that a parent can shut the motor down. Like a remote for a car that opens locks

Send Toystory a PM regarding that. I seem to remember him doing that with a Ride On Lawn Mower that he did for the kids

 

[OzFab]

These are commercially available & relatively easy to install, but may be a bit pricey