Axle sprocket size

[Brad Rose]

What size sprocket would be recommended for a ten tooth clutch. I weight around 210. I’m running an 820. This is my first kart to run so I just need a starting point. I was thinking a 70-74 tooth.

Brad

[ted johnson]

Brad, it mostly depends on what track you're running at. A track with long straights and gentler turns might need a 10-66, whereas a tighter track with shorter straights may want a 10-72 0r 10-70. The 820 in stock tune on gasoline develops more torque and less RPM than a Mac would, thus can pull a smaller axle sprocket. It also depends on whether you run a dry clutch or an oil-filled one, and whether you run a box muffler, open header or an expansion chamber. Buy a few sprockets and experiment, or ask other guys who run 820's on the same track. Be sure the other guys are running stock engines. Ted

[Brad Rose]

Thanks Ted!
I may start with a 70 and see what happens. I’ll pick up a few different sets like you said and experiment. I will be running an 820 on gas with a box muffler.

Brad

[ted johnson]

Don't forget, Brad, NO MASTER LINKS in the chain! Use a quality chain breaker and push the pin back into the outside plate to reinstall the chain. Somebody ought to do a video of that operation for folks who're beginning. Ted

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Here is a pretty good little video on using a good chain breaker. You can buy one from Comet Kart Sales, or most other kart shops. Ted
https://www.youtube.com/watch?v=HcUH1OTjJ_s

[Jim Waltz]

Brad,

I know everyone says to not use master links........

On my race kart with 219 chain and a 14 hp KT100, that's what I do.

However, I have been running master links on my stock 820's for going on 10 years with no master link problems.  Bonbright Vintage 820's might be a different story.

I do run good quality chain, and I do make sure that the master link clip opening faces away from the direction of chain motion.

Oh, and the Coleman chain breaker is the best.  It is adjustable, as not all chain has the same dimensions.

https://www.kartoramainc.com/go-kart-par...-p66218577

[ted johnson]

Does Coleman make a No. 35 chain breaker? I didn't see one. Most vintage karters use No. 35. The No. 35 breaker in Kart O Rama is Fast Kart. Fast Kart makes a very good breaker. I've been using a similar breaker for over 10 years, though I don't remember the manufacturer. It uses 3/8-24 push screws rather than the more common 5/16-24 screws. It works smoothly and with little effort. RLV makes a great #35 breaker, though it ain't cheap. Last time I tried a master link, back in '76 or '77, it came loose and I lost the chain in the middle of a major B Limited event at the big Jacksonville kart track. LOOOONG walk back to the pits pushing my Wasp! We always put the closed end towards rotation direction, and I even tried the type that used a wire keeper. TJ