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Old 02-19-2020, 10:37 AM
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Default TAV destruction

So a thing happened while I was out riding my Murray today. Somehow I sheared the welds on the stationary sheave and had to push my kart about a 1/4 mile back to my shop to replace it. Luckily I had a new spare from GPS.

I only have a stage 1 kit with 18lb springs and the belt is still new. The governor is still in it too until i get my "go fast parts".

Has anyone else had this happen or is it just my bad luck?
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Old 02-19-2020, 11:39 AM
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suboptimal weld..
driven lock (say it jumped exactly ON the buttons for some reason [worn button mostly])
the belt cannot rise up the driver and pushes against the sheaves.
but that shouldn't pop the weld tbh, that should stall the engine. *shrugs*

Was that a chinese replica driver?
(I can't imagine Comet to have bad welds like that *shrugs*)

'sid

strange..very strange indeed.
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Old 02-19-2020, 12:27 PM
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Yes it was a cheap replica driver. Should I upgrade to a true comet driver? I'm sure they're made better.

It happened when I turned around and was going slow, then jumped on the throttle and I heard the weld snap
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Old 02-19-2020, 04:59 PM
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the problem cannot be the driver alone..
check the driven too
if it snapped onto the buttons any new driver will fail as well (not fatally, but eating belts)

That's the first failure I remember seeing from a well maintained chinese driver *shrugs*
but no weld can be bad enough to do such without cause IMHO
a sharp impact maybe (can't see any marks though)
just the moveable sheave creating the pressure to snap a weld bead?
*shrugs* hard to imagine..

You can buy just the fixed sheave though (original comet)
it's available on mfgsupply.com (karts, clutches etc.. you'll find your way it's fairly straight forward)

'sid

PS Oh, keep in mind that you have the bronze idler bushing installed if you run a 3/4" driver
otherwise the belt will sit a hair too low on the shaft to actually get onto the ramp all that well.
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Old 02-20-2020, 07:31 AM
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What do you mean by a sharp impact and snapping onto the buttons? Like going from a slow coasting speed to sudden full throttle?

The bronze idle bushing is brand new but has a mark or two now from the sheave welds shearing and the belt has some wear now as well
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Old 02-20-2020, 09:29 AM
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what I meant with sharp impact
is "mounted with a hammer"
or "giant bolder got slung up and hit the driver pulley"
or "belt got stuck, I removed it with a prybar and a mallet"
thinks alike.. nothing you can do with just a throttle cable and a footcontrol

Now to snapping onto the buttons...
the driven unit has rubber buttons on the moveable sheaves cam.
(where the fixed cam rests against when the pulley opens or closes fully.)

When those buttons wear out the fixed cam can move past them.
onto the ridge between the two adjacent buttons or past both into the next valley.

both will render the driven unit useless.
ON the ridge and the driven pulley will be fixed at max size.

In the next valley and it either is so heavily preloaded that it can't adjust properly but is in the upper third at all times
or lacks all preload and the belt runs in the lower third at all times.

None of that has anything to do with
(other than in case of already worn buttons maybe being a direct result of)
you kicking the pedal hard into the floor board

'sid
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