Need some advice

[bamajosh]

I have a Hammerhead Twister 50cc I bought 8 years or so ago for $100. My niece and nephew drove the wheels off of it and I passed it on to my sister in law's cousin. My daughter is 6 and I started looking for a kart for her and lo and behold, the kart I gave away I got back.

I have purchased a predator 79cc engine for it to replace the crappy little 50cc(39cc actual). The axle sprocket is a 50t sprocket. I am looking at picking up a 11t centrifugal clutch. I think the tire size is about 8", I'll get actual size tomorrow. Am I going to run into any issues with this setup? The go-kart weighs maybe 100lbs and my daughter is only 50lbs. Should I replace the 50t sprocket with a 60t?

 

[bob58o]

I have a Hammerhead Twister 50cc.

I think the tire size is about 8", I'll get actual size tomorrow.

.

The things I found when I searched hammerhead twister were larger buggies.

This might have 8" tires and weigh 100lbs.
Does your kart look like this?

 

[bamajosh]

No, it looks closer to this:

 

[Angelk]

well my thought would be that that is way to low of a gear ratio. 3 hp isn't all that much and that is a fairly substantial kart. I would put maybe a 72 tooth or 60 tooth minimum on the axle. Especially if its for a younger child. I'm no expert but what I could see happening is you burning through clutches pretty fast with the current setup.

 

[bob58o]

No, it looks closer to this:

Check that weight and tire size.
Similar karts I saw were around 175lbs dry.

225 lbs total with driver?
13" Rear Tires?

I wouldn't gear it 4.5:1 with only 3.5 lb-ft max TQ and what I'm guessing are at least 13" Rear Tires.
Forgetting about the lack of TQ to the pavement, are you OK with your 6 year old doing 30mph at the governed 3600 RPM?

Now getting to the TQ....
Maybe use an 80T, instead of the 50T if using an 11T cent. clutch and your tires are 13".