cr 80 gearing for sprint tracks

randy ricklefs · Joined: 17 Feb 2011 Posts: 35

could someone tell me a good gearing combo to start off with, this is my first kart the motor has been all rebuilt. i'll be going to local tracks here in so-cal cal-speed / adams / grange ,ect i have a 15 &16t drive & 24 axle

Randy Mckee · Posted: Sun Dec 16, 2012 3:50 pm Post subject:

Grange, adams, perris, calspeed are about the same top speed. I think you can throw the 16/24 on there and should be fine. If this is your first kart, you'll probably be somewhat slow and pickup pace in bunches as you get laps under your belt. So just put a gear on that's tall enough for the straight and worry about the finer shift points after you've learned the tracks, your kart and your driving style. Have fun!
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Randy
#123 TonyKart - S4 Stock Honda

randy ricklefs · Joined: 17 Feb 2011 Posts: 35

thanks randy yah just been to busy putting this thing together and i dont want anything to go wrong like gear it to low i would think that would not be good for the motor so is 16/24 considered high ?

Randy Mckee · Posted: Sun Dec 16, 2012 10:05 pm Post subject:

It depends how fast you want to go. Laughing

16/24 is good for about 80 mph at 13K rpm on a cr80. I have no idea if your motor will rev that high. Regardless, a stock honda 125 will reach about 80 to 85 at most of those tracks, so your 16/24 should be plenty of gear for a cr80.

You'll probably switch to a shorter gear after you've done some laps and want to try different gears to see what feels comfortable. Don't worry too much about that at first. Go drive.

And let us know what jetting you've got in there. Some of those tracks you mentioned will differ greatly for jetting requirements. Better to be safe and not kill your new toy.
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Randy
#123 TonyKart - S4 Stock Honda

Gary M Smith · Posted: Mon Dec 17, 2012 5:32 pm Post subject:

Hi Randy,
I've been running 80cc shifter for about 4yrs now. I started out with 15/24(1.6) and now run 17/27 (1.588). I run the same tracks in the So Cal area that you will be running. I tried 16/24 (1.5) and the motor seemed slugish.
Are you running a Mikuni or the stock Keihin carb? The Mikuni carb with pump around is the way to go on these cr80 shifters.
Gary
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#55 Honda CR-80

randy ricklefs · Joined: 17 Feb 2011 Posts: 35

HI Gary this is the info i've been looking for someone running an 80 from around here you are the second guy from around here running 17-27 so i'll be buying them, all ready have a new chain motor is stock except for the mikuni with pump around and a vortex x10 ignition i got to see what jetting ive got in it now and post it here to see what you guys think