Rookie engine and clutch questions

[Santis]

Hello I'm new to the website and kart building in general. If this post is in the wrong place or my questions were answered somewhere else feel free to remove this post. Anyway, I had come across a a Chinese quad 110cc. I came up with the idea to try and make it into a kart. So I cut the frame in half and extended the whole body to make room for a seat. I bought a 212cc speeco engine brand new and also 2 cheap centrifugal clutches. I mounted the engine, installed the clutch, everything seemed to be going too well. When I decided to try it out just to see if it would go it seems to not have any power at all. Being that I have no experience with karts or any type of clutches or even engines this was not a surprise. A lot of research on this site leads me to believe I either have a gear ratio problem or maybe I need to adjust the governor on the engine. There are 10 teeth on the clutch and 36 on the sprocket that's on the axle. I understand that this is not a very good ratio for karts. When the back wheels are in the air they will spin when the clutch engages but when I let them down they still want to spin just have no power. Could this be because of the gear ratio or does this sound like an rpm problem? Or maybe the whole frame is to heavy?(it's only maybe 60 pounds with the engine. Any help would be appreciated. I will try and post a video of the most power I have gotten out of it which was enough to get moving with me standing on it but shortly after I leave the screen it won't move again, it tries just no power.

 

[Zombient]

First off, thank you for doing research! It's nice having someone actually research the issue before just asking questions that have been asked 1,000's of times before. To be honest, I've been guilty of that before...

But yes, that's a terrible gear ratio. That's a 3.6:1 ratio. You need to bump it up to at least 5:1 for it to move. But even that's still low, especially with those tires; they look like a pretty good size. I'd say a 60+ tooth sprocket would work better for you. What size are the tires?

 

[Santis]

The tires are 16 inches across. The gear ratio seems understandable considering I'm using the sprocket that came on the quad and the clutch that came on the quad came with only 9 teeth. I'll be looking into a new sprocket this week. Thanks for the help.

 

[Tgh567]

Yah if you get a bigert spot key probably 60 or 72 teeth would be best

 

[Poboy kartman]

Yah....u cood tek a lattle tyme and spill chik...

 

[mckutzy]

Yup I reckon more of the pill chicks......


Oh wait a min..... :/

 

[chancer]

The tires are 16 inches across. The gear ratio seems understandable considering I'm using the sprocket that came on the quad and the clutch that came on the quad came with only 9 teeth. I'll be looking into a new sprocket this week. Thanks for the help.

The quad probably had a transmission not a clutch. That is why it worked.
This is an interesting little project, but for a go kart it is waaay to long and narrow. You may get it to drive with the correct gear ratio but just dont expect "go kart" handling. More like a weird wild ride you can dare your friends to try.

 

[Poboy kartman]

It'll be fine...as long as he doesn't turn.....

 

[landuse]

A bigger sprocket is the way to go. I would suggest a 72T. Just make sure you will still have some ground clearance with a sprocket that large. If not, you might need a jackshaft

 

[Santis]

Yeah I didn't take handling into account. It's just a winter project and hopefully the first of many. I can just make it a drag racer. I did manage to get it to go.... Slow but it goes I can ride it like a skate board with one hand on the handle bars and the other on the throttle. I'm bending some steel in the shape of a seat. Once I weld the seat in I plan on making some sort of roll cage and braces

 

[landuse]

Yeah I didn't take handling into account. It's just a winter project and hopefully the first of many. I can just make it a drag racer. I did manage to get it to go.... Slow but it goes I can ride it like a skate board with one hand on the handle bars and the other on the throttle. I'm bending some steel in the shape of a seat. Once I weld the seat in I plan on making some sort of roll cage and braces

With the gearing you have, you are going to burn your clutch out very soon

 

[OzFab]

This is an interesting little project, but for a go kart it is waaay to long and narrow. You may get it to drive with the correct gear ratio but just dont expect "go kart" handling. More like a weird wild ride you can dare your friends to try.

Short of changing the entire rear axle assembly, there's not much you can do with the rear end but, it's not difficult to widen the front end...

If you can move the engine back or even back & up a little, you could shorten the frame too; doing both should give you more "reasonable" dimensions...