Chinese go-kart / dune buggy

[Der Hosser]

Looking for some advice here...
I bought a Chinese "off-road go-kart" online for my kids. It has a 200cc / 6.5hp Lifan motor and a 2:1 gear reducer on it. Drive sprocket is 15 tooth and axle sprocket is 43 tooth. 16" tires on the back. It wasnt able to move me straight out of the box (claims weight limit is 350 and I'm at 200). Also needs a push to get going with just my 60 pound son in it. Hills, it doesn't have a prayer. I put a stage 1 kit on the motor (intake, exhaust, new main jet) in hopes of boosting power - no dice. Its barely a month old and can't even go in the grass. Any suggestions? I know gear ratio is a big issue, but not familiar with the gear reduction systems and/or whether that compensates at all...help and thanks!

 

[Bwdeaton]

A total ratio of 5.73 to 1. That sounds too tall for the size of tires and weight of kart. Doesn't look like there is much space for a bigger axle sprocket. I wonder if you can find a smaller drive sprocket. What does the output shaft look like?

 

[Der Hosser]

Im pretty sure it is 5/8" (maybe 3/4"), keyed, and threaded at the end. I'll get a few pics here soon.

 

[Bwdeaton]

What size chain is it?

 

[Karttekk]

Can you supply the brand and model of that kart/buggy?

 

[Der Hosser]

Here's the side view of the drive shaft. There's no real brand of the kart...I bought it from RedFoxPowersports.com (horrible experience by the way) and they list the model # as
DF 200 GVF. The engine is made by Lifan and that model # is 168F-2R.
Not sure the weight of the chain, but it measures half an inch between pitches, so 40 (?).
Thanks guys!

 

[landuse]

Your gear ratio is 5.73:1. That is too high to get you going. There are 3 things to rectify this tall gear ratio. The first is to get a smaller reduction box sprocket (I would say a 10T would be ideal), the second would be to get a larger axle sprocket, and the third way would be to get smaller diameter tyres. I would go the reduction box sprocket route if it were me.

Why the gearing would be so terrible on a kart directly from the factory is a mystery to me.

 

[Der Hosser]

Thanks for the info! Yeah, I've been fully unimpressed by the kart and the company I got it from. But, oh well...
By the "reduction box sprocket" you're referring to the drive sprocket, right? If so, anyone have any suggestions where I could get a 10T sprocket with 3/4" bore? Thanks again.

---------- Post added at 11:30 AM ---------- Previous post was at 10:33 AM ----------

Also, any hints on how to get the keyed sprocket off?

 

[Bwdeaton]

Yes, the drive sprocket. Here's a sprocket online. I'm sure other places sell it as well, this is just the first that came up for me.
Ebay link

With the bolt removed from the end of the shaft, and the chain out of the way, the sprocket should slide off of the shaft.

 

[Karttekk]

Probably too late now but your best bets on buggies are either Trailmaster or Hammerhead. Parts and support readily available on both. Any chance of a return on yours?

http://www.hammerheadoffroad.com/

http://www.bvpowersports.com/

---------- Post added at 02:24 PM ---------- Previous post was at 02:18 PM ----------

This "About Us" section is a bit suspect.

https://www.redfoxpowersports.com/about-us

 

[ezcome-ezgo]

You think?
"Quality product by handpick the best manufacture to work with us"

 

[Der Hosser]

Yeah, it was a horrible experience...I was lured in by the pricing. But, it arrived scratched and missing pieces. It took more than a month and a half to get them to send me the missing tie rod (yes, they only sent one tie rod with the kart) and missing bolts. Do NOT buy through them.
Anyhow, thanks to everyone who helped on this thread, and I will let you know what happens when I get that new drive sprocket on (should be here Friday�&#56833.

 

[landuse]

Reading their website has now given me a headache :|

Literally copy and paste from google translate

 

[Der Hosser]

So, finally got the sprocket Bwdeaton suggested and it won't fit on the axle shaft. I had to use a gear puller to get the original off, but now it slides freely on and off. The replacement won't even start to go on - seems like it's barely too small. Do you think that it's a manufacturing issue on the sprocket? Or did my go kart maker use some obscure axle diameter that's slightly bigger than 3/4" but definitely not close to 1"? I sent a message to the seller of the new sprocket, but just curious if anyone here had any ideas. Thanks again, guys.

 

[anickode]

Probably 20mm. That's like 0.787 inches. Being as it's a Chinese buggy, that's where my money is.

From the look of it, they took a cart that was designed to have a GY6 type engine and just smacked a Honda clone on it without giving any thought as to anything else.

 

[Der Hosser]

Huh. Awesome. Well, in about a week when I get another 3/4" bore sprocket, we shall see if it fits or not, and I'll let you know.

 

[anickode]

If it won't fit, you could take it to a machine shop and just have it bored out a bit. Shouldn't take but 10 minutes of lathe time. Might need to make a custom key for it, but that's pretty simple too with a die grinder and some files.

 

[Der Hosser]

Thanks, anickode, I went ahead and ordered a branded 20mm sprocket too, just to be safe. Will post updates when I know anything else.

 

[Bwdeaton]

Just saw this, but I agree, being foreign it could very well be 20mm. Wish I had thought about that before you bought a 3/4 one, but it is possible you could have it turned on a lathe.

 

[PanelDeland]

My suggestion is to buy a caliper the next time you're in harbor freight and you'll be able to check diameters without worry. It's a handy tool.