Belt slipping. Wack gear ratio?

[Redneckarts]

I have a kart I built fresh. Got it all put together and if I go slow it catches and can drive it fast. But if I mash the gas or even start normally the belt gets caught in the driven pulley (not engine) which fails to bring the belt back up. Here’s some pics. I imagine my gear ratio is off or my pulleys aren’t the right distance apart. (Belt is off to move it around) (it’s correct belt because I used same setup on another kart with different gear ratio; 14t:52t)

Inner: 12 tooth
Live Axle: 36 tooth
40 series tc with 22hp 440cc (modded)
6in wide 8in tall slicks

 

[Redneckarts]

here’s what it looks like after it catches and I turn it off

 

[BaconBitRacing]

Your gear ratio is not good. I will say that’s a very nice looking kart! Slicks on a big suspension kart isn’t something I’ve seen before. Ideal ratio is 6:1, six like 10t driver and 60t driven. I’d also check the belt alignment while I’m at it.

 

[ezcome-ezgo]

I'd like to sell you some washers.

 

[BaconBitRacing]

I'd like to sell you some washers.

Saw-Glu for anti seize as well.

@Redneckarts, what my mildly insane friend here is trying to say is the torque converter issue is your belt alignment, so some washers and a good straight edge will do the trick for part of it. Spending a few minutes and a few bucks for washers and getting the alignment absolutely perfect will make your belt last a heck of a lot longer and mostly fix your issue. But the gear ratio needs attention as well.

 

[Snaker]

View attachment 137545
here’s what it looks like after it catches and I turn it off

Yeah, alignment is critical
Also, the second photo shows the driven pulley pucks on the wrong side of the cam ramps.
Pucks need to be on the other ramps so the movable sheave rotates against the belt rotation on upshifts.

The driven pulley contra spring has to have the correct wind as well.
It should wind tighter as the movable sheave rotates open

 

[Redneckarts]

Yeah, alignment is critical
Also, the second photo shows the driven pulley pucks on the wrong side of the cam ramps.
Pucks need to be on the other ramps so the movable sheave rotates against the belt rotation on upshifts.

The driven pulley contra spring has to have the correct wind as well.
It should wind tighter as the movable sheave rotates open

Ok please explain as if I don’t know what any of those big words mean haha

 

[Redneckarts]

I'd like to sell you some washers.

Haha it’s temporary until I get the right length spacers and bolts. Just made from whatever I had laying around. It was also to clear the frame with the gas tank

 

[Snaker]

Saw-Glu for anti seize as well.

@Redneckarts, what my mildly insane friend here is trying to say is the torque converter issue is your belt alignment, so some washers and a good straight edge will do the trick for part of it. Spending a few minutes and a few bucks for washers and getting the alignment absolutely perfect will make your belt last a heck of a lot longer and mostly fix your issue. But the gear ratio needs attention as well.

I'm thinking it was more of a shot at the engine mounts.
Am I right?

 

[BaconBitRacing]

I'm thinking it was more of a shot at the engine mounts.
Am I right?

Haha I think you may be right! EZ always knows how to find customers for anything.

 

[Snaker]

Ok please explain as if I don’t know what any of those big words mean haha

The driven pulley movable sheave cam has ramps in both directions.
The set of ramps to use is based on the mounting orientation of the pulley set.
If that pulley were mounted flipped around from what you have, then you would use the set of ramps your presently on.
But again, follow the rule of:
The driven pulley movable sheave has to rotate against the belt rotation during upshift.
And it rotates with the belt rotation during downshift.

 

[Snaker]

Also, with that long jackshaft at the driven, I think you would have a good candidate for flipping the drive pulley (you said its a 40 series, right?)
That would really help the belt work as intended with that driven pulley orientation.

 

[Denny]

Your secondary is on backwards is what everyone is saying. Second, your gear ratio is way too high. With those tiny tires back there the you might get away with a 5:1 ratio but no higher. If you fix those 2 things then you’ll be golden.

 

[panchothedog]

Your driven clutch is messed up. In the picture it is open. In its relaxed position it should be completely closed, and open up like it is in the photo only once top speed is achieved. The points of the cam, or ramps are centered between the plastic tabs. This is wrong. They should be pulled back hard sitting against, and
in front of the tabs. I don't think you have any spring pressure. It looks like you have a bushing on the end of the clutch. It is supposed to be held together with a snap ring. Lots of videos on how to change springs on a 40 series torque converter. You don't need to change the spring, just need to wind and install it correctly. Take yours apart, find a video you can understand and proceed from there. BTW, nice kart. Should really haul once you get it dialed in. Your gearing is probably too high, but with 10" tires you don't need to go all the way down to
6 to 1. Get your driven clutch straightened out, put on a 10 tooth instead of the
12, and get ready to haul.

 

[redflash]

THE next problem you will run into is.......you need a 60 tooth sprocket on the axle ( you've been told that already)......but to begin with that is not a racing Kart in spite of the huge and powerful motor......that Kart never had slicks on it in it's life......here's the problem .....pay attention....
when you put a 60 tooth sprocket on the axle....that sprocket and chain may hit the ground because of the tiny tire diameter. a 60 tooth sprocket is about 10 inches in diameter.......then ( as always there's a THEN) because of the power of that engine and the correct gearing, you SHOULD put 16-18 inch tires for a correct ride height. so rework the torque converter, buy the sprocket, buys the rims and tires, and enjoy off-roading which is what that Kart was made for !

Da redflash

 

[BaconBitRacing]

THE next problem you will run into is.......you need a 60 tooth sprocket on the axle ( you've been told that already)......but to begin with that is not a racing Kart in spite of the huge and powerful motor......that Kart never had slicks on it in it's life......here's the problem .....pay attention....
when you put a 60 tooth sprocket on the axle....that sprocket and chain may hit the ground because of the tiny tire diameter. a 60 tooth sprocket is about 10 inches in diameter.......then ( as always there's a THEN) because of the power of that engine and the correct gearing, you SHOULD put 16-18 inch tires for a correct ride height. so rework the torque converter, buy the sprocket, buys the rims and tires, and enjoy off-roading which is what that Kart was made for !

Da redflash

Red, he may not need off road capabilities, and with small tires he can run a higher ratio. Definitely not this high, though. I say let he can roll how he likes, even if it's repurposed. I'm pretty sure he doesn't want a back-breaker so suspension, but he doesn't want to ride off road, so slicks. Though personally I would go with stock style tires and wheels.

 

[BrownStainRacing]

I kinda like the small tires, it's definitely different then most I see around this area.

That big block is gonna make a ton more torque then any small block, no need in big gearing with those short tires.

Jus my .02 cents worth.

 

[redflash]

the size, diameter of those slicks will NOT allow him to put a bigger sprocket on the axle ! He will drag the sprocket !
If he wants to drag race that thing OK, but it would be totally unsafe on a road, so where the heck can he air it out........set it up for off-road is my .03 cents worth.

that chassis will not corner at those speeds.....unsafe !

Da redflash

 

[BrownStainRacing]

Also, with that long jackshaft at the driven, I think you would have a good candidate for flipping the drive pulley (you said its a 40 series, right?)
That would really help the belt work as intended with that driven pulley orientation.

I say flip the driven over the way is was designed, line belt up with driver.

What size belt is that???
It don't look wide enough on the driver.

8" tall tire, 3:1 gear, under a gov'ed engine..... will be lucky to hit 30 mph.

 

[redflash]

we'll see .