Clutch not engaging

[WadamMomo]

I'm currently running a standard gx240 on my kart with a 14 tooth clutch and a 41 tooth sprocket, I know the gearing is low but I couldn't find a higher tooth sprocket for my clutch

However today I was supposed to drive it for the first time but the clutch wouldn't engage until I was at maximum throttle and even then I would only go barely 2 mph

Could I need a new clutch?

 

[bob58o]

With 2.9 : 1 sprocket ratio it is likely that the clutch is burned up. You said it was your first time trying to drive it, but if it was like that with a previous owner then the clutch probably is already gone.

If a standard centrifugal clutch that engages around 1800 RPM is paired with 13” tires and the sprockets you mentioned…. You basically need a car to push you to 25 mph every time you start from a stop. If larger than 13” tires… it’s even worse.

How big are your tires? The diameter?
Clutch with 10T and rear sprocket with 60T ( 6 : 1) is a better option that works for many karts.

A clutch with less teeth will help, but you probably need a bigger rear sprocket or will burn up the new clutch too. Or convince a group of friends to help with push starts.

 

[Denny]

10:60

 

[bob58o]

Kart Team in Training…

 

[WadamMomo]

With 2.9 : 1 sprocket ratio it is likely that the clutch is burned up. You said it was your first time trying to drive it, but if it was like that with a previous owner then the clutch probably is already gone.

If a standard centrifugal clutch that engages around 1800 RPM is paired with 13” tires and the sprockets you mentioned…. You basically need a car to push you to 25 mph every time you start from a stop. If larger than 13” tires… it’s even worse.

How big are your tires? The diameter?
Clutch with 10T and rear sprocket with 60T ( 6 : 1) is a better option that works for many karts.

A clutch with less teeth will help, but you probably need a bigger rear sprocket or will burn up the new clutch too. Or convince a group of friends to help with push starts

I'm not sure about the tires but they are jets wet tires

About the rear sprocket, because I'm running a gx240 I can't find a clutch that uses a smaller pitch chain so I'm pretty much forced to use a #41 chain
This limits my options for rear sprockets by a lot.

I'll probably order a new clutch for now and continue to look for a larger rear sprocket

 

[Whitetrashrocker]

Your new clutch will burn up. Your throwing money away.
Fix your sprockets and chain.

 

[BaconBitRacing]

I'm not sure about the tires but they are jets wet tires

About the rear sprocket, because I'm running a gx240 I can't find a clutch that uses a smaller pitch chain so I'm pretty much forced to use a #41 chain
This limits my options for rear sprockets by a lot.

I'll probably order a new clutch for now and continue to look for a larger rear sprocket

Get out a tape measure and check, it's important. WTR is right. Do it right the first time and save money.

 

[bob58o]

Not sure the bolt pattern on your sprocket carrier… A cheaper clutch might work… I generally don’t use them so not too familiar with HP ratings and limits in real life.

 

[bob58o]

Question for the Gang:

Do they still make those 30 series TAV kits with 1” driver units? People used to try them on 420cc and fail, but with a 240cc they might work? Anybody try one of these on 240cc?

Go Kart Torque Converter Clutch Kit 30 Series 1 inch 12T #35 Chain 8-13HP | eBay

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www.ebay.com

 

[Jacka$$withawrench]

Not sure the bolt pattern on your sprocket carrier… A cheaper clutch might work… I generally don’t use them so not too familiar with HP ratings and limits in real life.

View attachment 149738View attachment 149739

You can get the same clutch of amazon for $45~ or 10$ is you have a buddy at Supply Depot (plus shipping).

 

[WadamMomo]

Get out a tape measure and check, it's important. WTR is right. Do it right the first time and save money.

I understand doing it right the first time but that doesn't solve my problem of sourcing the right parts.
I'm in the uk so it's extremely hard to get parts for a reasonable price, a £30 Sprocket becomes a £120 sprocket with £60 shipping.

 

[bob58o]

I understand doing it right the first time but that doesn't solve my problem of sourcing the right parts.
I'm in the uk so it's extremely hard to get parts for a reasonable price, a £30 Sprocket becomes a £120 sprocket with £60 shipping.

I’d check places like Amazon or eBay even AliExpress but I don’t know what’s available ‘cross the pond.

Might try a “Farm” store… here we have some big chain stores… farm and fleet, rural king, tractor supply,…. Sometimes they have “gokart” parts.

 

[WadamMomo]

I’d check places like Amazon or eBay even AliExpress

I've looked at AliExpress, eBay and Amazon and no dice.

Would I be better switching to a torque converter as I can find one that's a 1 inch bore with a pitch of #35 which I can find sprockets at 60 tooth and higher for

 

[bob58o]

I've looked at AliExpress, eBay and Amazon and no dice.

Would I be better switching to a torque converter as I can find one that's a 1 inch bore with a pitch of #35 which I can find sprockets at 60 tooth and higher for

I think it might be a good option but I’ve never tried that set up. I use 30 series with 3/4” driver units on 212cc so I ASSUME it a 30 series with 1” driver unit with work on a 240cc. With #35, maybe go with 12T and 72T on the rear (depending on tire size).

Is it 1” you need? Or do UK engines come like 25mm or sumthing? Maybe interchangeable? I dunno?

 

[bob58o]

Make sure mounting the kit won’t cause issues. Often you’ll need to raise the engine an inch or inch and a half to fit the TC driven unit mounting plate.

 

[WadamMomo]

I think it might be a good option but I’ve never tried that set up. I use 30 series with 3/4” driver units on 212cc so I ASSUME it a 30 series with 1” driver unit with work on a 240cc. With #35, maybe go with 12T and 72T on the rear (depending on tire size).

Is it 1” you need? Or do UK engines come like 25mm or sumthing? Maybe interchangeable? I dunno?

Uk engines use regular 1 inch shafts,
I might look into the interchangeable thing but I think I'll probably run a torque converter, I've seen that they give you better low rev torque anyways compared to a centrifugal clutch

 

[bob58o]

Uk engines use regular 1 inch shafts,
I might look into the interchangeable thing but I think I'll probably run a torque converter, I've seen that they give you better low rev torque anyways compared to a centrifugal clutch

Far and away better than centrifugal clutches for yard karting IMO

it’s like comparing a car with auto transmission to a car that either has only 1st gear or only 4th gear. With Centrifugal clutches you only get the one gear. If you set it up to move fast… you’ll never get off the line. Like starting in 4th gear from a stop. It doesn’t move, just burns the clutch. If you set it up for the clutch to last long, you probably won’t reach thrilling top speeds.

 

[panchothedog]

The 30 series torque converter is by far your best option. bob58o explained it very well in the previous post. The # 420 chain is stronger than the # 35 but if you're selection of sprockets is that much better, go with what's available.

 

[Darren]

I know you've posted on another site trying to sort this, post some photos.
I'll see if I can help, we really had no problems with my old thunder kart and my mates current kart.
The 1" bore corporate clutch will sort you out, the rear axle sprocket is the questionable bit.

 

[pearl111]

I'm not sure about the tires but they are jets wet tires

About the rear sprocket, because I'm running a gx240 I can't find a clutch that uses a smaller pitch chain so I'm pretty much forced to use a #41 chain
This limits my options for rear sprockets by a lot.

I'll probably order a new clutch for now and continue to look for a larger rear sprocket

Measure the tires .......from the top of the tire...to the ground...... = diameter.