Clutch use on shifter kart?

[Ed hodgson]

Hi. Quick question for the shifter crowd. I’ve been testing and tuning my (CR 80) shifter kart last couple days.

I only use the clutch for starting out. I upshift and downshift without the clutch, but I make sure I’m off the gas on upshifts, and I try t to match RPM’s to the gear I’m downshifting to, also off the gas, so as not to have it “red-lining” going from 4-3, etc.

Is this ok for the transmission on the engine? I’ve heard the vast majority of the shifters do not use a clutch for shifting.

Yesterday, I panic-braked hard (forgot to pull in the clutch) and the kart died in gear and slid for a bit. Hoping this didn’t do some sort of damage.

Any and all input is appreciated

[David Cole]

Yes, you only use the clutch to take off. You can only upshift off the gas, and most of the time you can quickly down shift, if it’s a hard braking corner.

Here is the best American shifterkart driver Gary Carlton driving a KZ kart. The engine has higher RPM then an 80 will, but you will see how he works the gas and hear the sound of the shifting.

David Cole - EKN Managing Editor

[Ed hodgson]

Thanks that’s a great vid!

new to shifters, don’t want to accidentally hurt something

 

[Chuck hurlbert]

if it doesn’t go in gear, hit the shifter harder!!!  :)   I don’t know about an 80 but a 125 is next to bullet proof.  im on year number three and the previous owner didn’t have a clue when the tranny was rebuilt when I bought it.

but you are right, get off the gas and back on as quick as you can going up in gear.  bang on it going down.

[Dave Holstein]

A CR80 will need a billet third gear to be virtually bullet proof.

[Gary Smith]

+1 on billet third gear, I blew stock one up and quit counting dollars at $400 to repair the damage. I bought an ebay bottom end for $130 and replaced 3rd gear with billet, works perfect and no fear of another failure.

Up shifting the transmission will not shift unless you let off the gas, down shifting, as you start slowing down, down shift, try to match your corner exit speed to your engine RPM, once you do this for a while you will find a rhythm, listen to the engine, it will tell you the RPM it wants to be.

Gary

#55 Honda CR80

[Ed hodgson]

Thanks for the replies, one and all

I’ve raced dirtbikes, and used the clutch a lot on those,  controlling the power out of corners, etc.

When I’m riding this kart, I do let off the gas to upshift, it feels very smooth.

On downshifts, I let the engine de-celerate to where i think the next lowest gear would be at, and it downshifts very smooth too, sometimes I come into the lower gear a tad “hot” and the engine revs a little, but it’s not screaming its brains out. When I panic-braked and the engine quit in gear, I slid, but the engine was off, no rotation was taking place.

Shifting through the gears while engine is off is very smooth too; no weird clunks or sticking.

I’m just trying to pay very close attention to things, due to this being the first time I’ve ridden a gearbox-equipped kart.

*as far as the billet 3rd gear, where is a source for those?*

thank you all again!

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