Need setup advice

[joshw0000]

Hi group,

My kids have a Chinese go kart (full suspension and roll cage) that once had a 110cc engine. I replaced the engine once before but it always had issues. So I recently did a major change to the cart. It has a live axle with a 43 tooth rear sprocket. I left that as-is as the old 110cc motor used the sprocket with 428 chain and getting that sprocket off the axle would be a PITA.

I removed the old engine, cut out the old bracing and welded in a new plate for a Predator 212, along with a 13 tooth front sprocket/clutch and 428 chain. This weekend I broke in the new engine and attempted a test run before setting the kids loose. I weight about 190 and the new setup will barely even move me at WOT. I've checked the clutch and re-oiled it. The chain isn't too tight. The 2 sprockets seem to be properly aligned and not binding. I didn't feel any resistance when I push the cart. It will roll down my driveway and propel me a little bit but when I turn to drive through the yard it's slipping to the point that it's no longer moving.

I'm no expert but from what I've researched the 43T sprocket/428 chain/13T combo should be compatible with each other. And the Predator 212 should be powerful enough to move the cart with me or 2 kids.

Can anyone give me any suggestions?

 

[BrownStainRacing]

Hi group,

My kids have a Chinese go kart (full suspension and roll cage) that once had a 110cc engine. I replaced the engine once before but it always had issues. So I recently did a major change to the cart. It has a live axle with a 43 tooth rear sprocket. I left that as-is as the old 110cc motor used the sprocket with 428 chain and getting that sprocket off the axle would be a PITA.

I removed the old engine, cut out the old bracing and welded in a new plate for a Predator 212, along with a 13 tooth front sprocket/clutch and 428 chain. This weekend I broke in the new engine and attempted a test run before setting the kids loose. I weight about 190 and the new setup will barely even move me at WOT. I've checked the clutch and re-oiled it. The chain isn't too tight. The 2 sprockets seem to be properly aligned and not binding. I didn't feel any resistance when I push the cart. It will roll down my driveway and propel me a little bit but when I turn to drive through the yard it's slipping to the point that it's no longer moving.

I'm no expert but from what I've researched the 43T sprocket/428 chain/13T combo should be compatible with each other. And the Predator 212 should be powerful enough to move the cart with me or 2 kids.

Can anyone give me any suggestions?

How tall are the rear tires??? 43t/13t is only a 3.30:1 gear. That might be enough gear for a 13" tall tire and a 100 lb rider.
Lets say that engine makes 9.5 lbs of torq at 2800 rpm, jus a reference but close, now 3.30 x 9 = 29.7 lbs of torq to the tires. That's no where in the ball park to pull 190 lbs.
That clutch will not last long. You need a 30 series TAV, but I don't know where to find a 428 sprocket to fit.
Maybe, you could add another gear reduction, ( jackshaft) that would help, but still not good for a clutch.
I find it best to get a new live axel kit with bearings, hangers, and sprocket to match. That old sprocket may never come off, without destroying the axel.

 

[Denny]

Your gearing is way wrong! You should be running atleast a 6:1 ratio. Meaning 10 tooth clutch and 60 tooth axle sprocket. Centrifugal clutches are only for steady wide open throttle and paved roads. You should upgrade to a 30 series TAVII CVT for off road riding.

 

[joshw0000]

How tall are the rear tires??? 43t/13t is only a 3.30:1 gear. That might be enough gear for a 13" tall tire and a 100 lb rider.
Lets say that engine makes 9.5 lbs of torq at 2800 rpm, jus a reference but close, now 3.30 x 9 = 29.7 lbs of torq to the tires. That's no where in the ball park to pull 190 lbs.
That clutch will not last long. You need a 30 series TAV, but I don't know where to find a 428 sprocket to fit.
Maybe, you could add another gear reduction, ( jackshaft) that would help, but still not good for a clutch.
I find it best to get a new live axel kit with bearings, hangers, and sprocket to match. That old sprocket may never come off, without destroying the axel.

Rear = 16x8-7
Front = 145/70-6

 

[BrownStainRacing]

Rear = 16x8-7
Front = 145/70-6

Same as my grandsons buggy from factory. It came with a subaru engine, 30 series tav w/6" driven and 6:1 gearing, from factory. It pulled good, nothing to brag about. It now has mildly built(9.6:1 CR) predator 212 non hemi, 19" rear tires, 6.66:1 gear and 7" driven w/ yellow spring, pulls like a monster, and climbs the steepest hills, without hesitation.
The 110 has a gear reduction internal, and the chain and sprockets added another gear reduction. You gonna need to help the predator out a little, I think a 30 series tav, with 7" driven and 6.66:1 gearing will get it there.
there's jus no way it's gonna pull 16" tires with a 3.3:1 gear and a clutch.

 

[BaconBitRacing]

Welcome to the forum! Follow BrownStainRacing's advice. Since you already have a clutch you could use it once your gears are setup, but don't expect long life, good climbing abilities, low end, or great acceleration. Definitely go for a 30 series torque converter. The Chinese Amazon ones are fine, but get a genuine Comet belt. The China belts are made of Yak grease and rice fiber.

 

[BrownStainRacing]

Heres something else to think about. It has internal gear reductions, 1.3:1 forward, and 2.6:1 reverse. Matched with a 30 series, 7" driven, and 6.66:1 gear, would make a nice stump puller.

Go Kart Transmission | Go Kart Forward Reverse Gear Box

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[bigjake]

Agree with above more gear needed it will be worth the work of swapping rear sprocket to atleist 60t with 10 front on a tc
A clutch is only good for 15 inch tires and smaller and even then needs to be a good clutch
Had a Coleman bike I put a tc on and a 70t rear 10t front with 19 inch tires and it would pull a fat guy up a hill pretty good

 

[joshw0000]

Ok, thanks everyone. So now where do I start? I had previously tried to remove the rear sprocket with no luck. I couldn't get the axle lose to remove it. Or at least without damaging it. If I'm being completely honest it may already be slightly warped from me trying to tap it loose (I started by buying a torque converter and 40 series until I realized it wouldn't fit the rear sprocket).

If, and that's a big if, I can get it loose, how do I know which axle to buy? I'd also have to replace the braking system, which I'd rather not do.

Are there any alternatives that will work with the 43T currently on it? Or if I cut it off with a grinder, is there a 2 piece that I can replace it with?

 

[joshw0000]

I'm already upside down in this go kart...but let's say I buy a new axle and front sprocket, what's ideal to go stupid fast on grass. The cart has a roll cage and seat belts. And I make the kids wear helmets. They're 10 and 12. I don't think more speed will hurt them at this point.

And even if I'm replacing the clutch fairly often, they're cheap enough. What's the most cost effective kit I can buy to make this go kart as fast as possible and reliable? Ideally not more $100 or $200 but if it is, it is.

 

[Thepartsguy]

I'm already upside down in this go kart...but let's say I buy a new axle and front sprocket, what's ideal to go stupid fast on grass. The cart has a roll cage and seat belts. And I make the kids wear helmets. They're 10 and 12. I don't think more speed will hurt them at this point.

And even if I'm replacing the clutch fairly often, they're cheap enough. What's the most cost effective kit I can buy to make this go kart as fast as possible and reliable? Ideally not more $100 or $200 but if it is, it is.

No clutch is gonna move you with that 43t rear axle sprocket. if you made the t/q work I still doubt it would move.

 

[joshw0000]

No clutch is gonna move you with that 43t rear axle sprocket. if you made the t/q work I still doubt it would move.

I'm beginning to realize that. I'm still a noob to chains and sprockets. Can you help point me in the right direction from my current status?

 

[Denny]

First of all they are not roll cages. They are merely brush bars. Second forget about stupid fast and grass. You can either be able to ride it on the grass or not. You can have one or the other but not both, the laws of physics say that not me. Now that we got all the caveats out of the way. You will need to clean all the rust off your axle to shiny metal for starters and start soaking it all down with penetrating oil, then heat and beat time will start after about 2-3 days of soaking. Depending how bad you tear stuff up, that is what you’ll need to replace. Good clear pictures will go a long way to us helping you. And what size engine is on there?

 

[BaconBitRacing]

I'm beginning to realize that. I'm still a noob to chains and sprockets. Can you help point me in the right direction from my current status?

Almost no matter the age of your kart things will be seized. I have a Streaker from the 80's and all the axle and wheels and sprocket is seized. For some reason the factory couldn't be bothered to put anti-seize on things. Also, try and resist the urge to cut it apart. Thanks for being responsive and do not forget to put anti-seize the you reassemble it. We all didn't understand chains and sprockets at one point, don't be hard on yourself. If you want to learn some basics, hit the 'All the way Home' button then read the pages; torque converter, centrifugal clutch, sprockets and chain sizing. This will help you learn the basics.

 

[joshw0000]

First of all they are not roll cages. They are merely brush bars. Second forget about stupid fast and grass. You can either be able to ride it on the grass or not. You can have one or the other but not both, the laws of physics say that not me. Now that we got all the caveats out of the way. You will need to clean all the rust off your axle to shiny metal for starters and start soaking it all down with penetrating oil, then heat and beat time will start after about 2-3 days of soaking. Depending how bad you tear stuff up, that is what you’ll need to replace. Good clear pictures will go a long way to us helping you. And what size engine is on there?

They did roll it once and it didn't crush them. So I'd say the bars over their head worked. Honestly this thing isn't that old and hasn't spent any nights in the rain so it's not corroded. The engine is a Predator 212.

Here's a few photos.

I can, and have, unbolted the rear sprocket but ended up bolting it back on after stripping the right rear tire assembly down to the axle and trying to tap it loose. I didn't remove anything on the left side other than the brake caliper so that probably played a part in making it less easy to tap loose.

It sounds like I don't really have a choice but to undo both sides and figure out how to get this thing off. Then take measurements from the old sprocket to figure out the bolt configuration. So a 60T is best with a 10T front sprocket and #40 chain?

 

[BrownStainRacing]

I'm already upside down in this go kart...but let's say I buy a new axle and front sprocket, what's ideal to go stupid fast on grass. The cart has a roll cage and seat belts. And I make the kids wear helmets. They're 10 and 12. I don't think more speed will hurt them at this point.

And even if I'm replacing the clutch fairly often, they're cheap enough. What's the most cost effective kit I can buy to make this go kart as fast as possible and reliable? Ideally not more $100 or $200 but if it is, it is.

Post up pics of what you have to work with, engine plate, axle hangers, bearings, swing arm.

 

[BrownStainRacing]

They did roll it once and it didn't crush them. So I'd say the bars over their head worked. Honestly this thing isn't that old and hasn't spent any nights in the rain so it's not corroded. The engine is a Predator 212.

Here's a few photos.

I can, and have, unbolted the rear sprocket but ended up bolting it back on after stripping the right rear tire assembly down to the axle and trying to tap it loose. I didn't remove anything on the left side other than the brake caliper so that probably played a part in making it less easy to tap loose.

It sounds like I don't really have a choice but to undo both sides and figure out how to get this thing off. Then take measurements from the old sprocket to figure out the bolt configuration. So a 60T is best with a 10T front sprocket and #40 chain?

Sorry, went to get coffee and missed pics.

 

[BrownStainRacing]

They did roll it once and it didn't crush them. So I'd say the bars over their head worked. Honestly this thing isn't that old and hasn't spent any nights in the rain so it's not corroded. The engine is a Predator 212.

Here's a few photos.

I can, and have, unbolted the rear sprocket but ended up bolting it back on after stripping the right rear tire assembly down to the axle and trying to tap it loose. I didn't remove anything on the left side other than the brake caliper so that probably played a part in making it less easy to tap loose.

It sounds like I don't really have a choice but to undo both sides and figure out how to get this thing off. Then take measurements from the old sprocket to figure out the bolt configuration. So a 60T is best with a 10T front sprocket and #40 chain?

Is that hub for sprocket and brake disc welded to the axel????

 

[joshw0000]

Is that hub for sprocket and brake disc welded to the axel????

Yes

 

[BrownStainRacing]

There's not enough room behind sprocket to go to a bigger sprocket.
This is gonna take some thinkin.