Tight TC belt?

[Denny]

The alignment is way off! Fix it! Take the clutch apart and see what is stuck and lube it with graphite.

 

[Skort]

I'm happy to try to fix it but what is supposed to align with what here? The two sides of each pulley need to be parallel, and the driver pulley needs to align with the driven pulley somehow, but is it the centers that should match up, or the inner edges, or what?
Thanks!

 

[Skort]

I got some spacer washers for the driver, and the alignment of the inner plates with each other is much better. Still not perfect (1 washer leaves it slightly too close, 2 slightly too far). This didn't help at all. The moving parts on both the driver and driven are moving as RPM increases, but it's not engaging the wheels with any force at all (they spin up on jacks but everything is slipping when there's any resistance).

 

[bob58o]

How is the sprocket attached to the jackshaft?
key built into sprocket?
Separate key?
Set screws?

Is the sprocket spinning in the jackshaft?

 

[Skort]

Not exactly sure how to answer that (I've never seen that part disassembled) but here's as good a picture as I can get and a video of the chains spinning. Basically, it looks like the chain is spinning at full speed on the clutch side, but the axle side is not really engaging. Also when you walk the card forward on the ground, it's not trying to turn the clutch side at all.

 

[bob58o]

I’m confused as to how the drive train is set up. A belt from engine to jackshaft #1, then a chain to jackshaft #2, then a chain to the axle?

does this sprocket/chain hit the shaft here?

 

[Skort]

I’m confused as to how the drive train is set up. A belt from engine to jackshaft #1, then a chain to jackshaft #2, then a chain to the axle?

does this sprocket/chain hit the shaft here?

That’s what it looks like, yes.

 

[Skort]

That’s what it looks like, yes.

Here’sa view from the bottom. Brass color is the axle and you can see the lower jack shaft clearly, and then the upper one a bit on the top right of the picture.

 

[bob58o]

This is a more complex drive train than I assumed.

My assumption is that one of 6 pulleys/sprockets involved in the drive train is freely spinning on its shaft.

I could be very wrong.
I’ve had keys break in the sprocket hub on the axle. They could break on any shaft.
Could be Driven Unit or the sprocket on that shaft. Could be either sprocket on next jackshaft. Could be sprocket hub on axle.

I could be wrong and all those could be ok. But my first guess is one of those is spinning freely (as in key or set screws came out)

 

[bob58o]

Maybe put it up on stands and turn the wheels by hand and apply resistance to various spots along the drive train and see if you can find a spot where it seems to be “disconnected”

 

[Skort]

The lower jack shaft definitely seems disconnected on the engine side. If you roll the cart, it clearly turns the sprocket on the right and you can see the left one “twitch” but not turn. Like the shaft itself is severed, but they seems unlikely.

 

[bob58o]

Perhaps investigate this sprocket.

It’s hiding like it’s been up to no good. That chain looks much dirtier and more beat up than the one next to it. The master link looks kinkier than (insert joke).

 

[bob58o]

I can’t tell how the sprocket hubs are connected to the jackshaft.

often a hub will be attached to a shaft with a key or set screw or a bolt that clamps… then the sprocket attached to the hub.

I can see where your sprockets bolt to the hubs, but can’t see how the hubs connect to the shaft. The axle hub looks welded on.

How is the sprocket flange connected to the shaft? I’m not sure.

 

[bob58o]

When you spin the wheels, everything should be spinning in sync back up to the driven pulley. A broken in belt (hopefully) slips when you push the kart, but everything from the driven pulley to the wheels should spin in sync. So if one sprocket on that jackshaft can turn without the other spinning, either the shaft or the hubs/flanges, or keys/screws holding the hub/flange to the shaft… is broken.

I think.

 

[Skort]

When you spin the wheels, everything should be spinning in sync back up to the driven pulley. A broken in belt (hopefully) slips when you push the kart, but everything from the driven pulley to the wheels should spin in sync. So if one sprocket on that jackshaft can turn without the other spinning, either the shaft or the hubs/flanges, or keys/screws holding the hub/flange to the shaft… is broken.

I think.

Yeah that’s what I would assume as well, it’s just very strange that after replacing the driver it drove great for like 30 seconds, I stopped, and then this seemingly unrelated thing happens.

 

[bob58o]

Maybe it was a poor design and the stress (torque) from the TC was known to cause issues so they put a bearing inside the driver unit to prevent the belt from pulling too hard?

now I’m just spitting ideas.

 

[Denny]

Sounds like you either broke a key or it fell out. Time to start taking stuff apart.

 

[Skort]

Turned out the bolt and washer holding in the sprocket on the axle side has fallen out. Nothing at all to do with my fix! All good now, thanks everyone for the pointers.

 

[Snaker]

Perhaps investigate this sprocket.

It’s hiding like it’s been up to no good. That chain looks much dirtier and more beat up than the one next to it. The master link looks kinkier than (insert joke).

Ah yes, that has the look of a pressed on Master Link that was pressed on too far.
If the rest of that chain looks good, I would get the chain tool and pull that link plate out a bit. Or just replace it?

 

[Skort]

And by the way, the increase in power since having replaced the driver is noticeable. It’s a little crazy how bad the quality control on the assembly of the powertrain was for a new product. As far as I can tell, the parts have all been good but were bolted together at the factory by someone who didn’t GAF.