Question Answer
What is the cost of getting into a kart? You can find a basic, running, functioning 125cc shifter kart for about $3000... but you don't want that one. For a one or two year old kart in good condition, with a decent motors and some reasonable spares, expect to spend about $5000.
What about other costs? Figure less than $200 for a set of tires. $5/gallon for gas. $10 for a bottle of oil. $5 for chain lube. Under $100 for a complete top end set.
What spares and other parts will I need? Kart suit, full face helmet, neck protector, gloves & shoes. Extra gear sprockets. Tire bead breaker. Chain breaker. Extra set of rims, possibly with rain tires on them. Spare axle (different stiffness?). Extra brake pads. Spare ring, piston & gasket set. Extra cylinder for a big race? Lots of water and Gatorade. Wallet.
Where can I race a shifter kart? For autocross, all National Tours, ProSolo's, Nationals and regional events in regions that allow it. You can also run your kart at dedicated kart sprint tracks and also on standard road race courses.
How fast do they go? Faster than you need!
No really, how quick are they? Most autocrosses we gear for about 70-75mph at the top of 6th and almost never hit that. On some larger sprint tracks you'll sometimes see 80-85mph. On a road course you'll get 110-120mph. Karts don't really have great high end speed, but they get there quickly and can hold it there around the turns.
How do they compare to other autocross cars? On most courses we're faster than CM but slower than BM. On tight courses we can sometimes beat BM, on fast sweepers CM can sometimes beat us. AM is almost completely out of reach (unless they're way out of downforce and gear). We're faster than just about everything else out there.
How much do they weigh? The minimum class weight is 385. Most karts will be around 200 pounds with a little bit of gas in it.
What chassis should I purchase? There really isn't one "perfect" chassis for every driver (in every form of the sport, at every track, etc. etc.). Popular in autocross are the Italian chassis from CRG and Renspeed. Generally the softer chassis seem to work better on a variety of surfaces especially when it's bumpy. Other brand names that are good are Tony, TrackMagic, CTS, Birel, MGB, just about anything. The best chassis to get is the one that has local parts and tuning support. If there's a local kart shop near your local track, find out what they're running and buy that.
How difficult are they to drive? They're not easy! Besides the increased speed and twitchiness, you have to deal with the shifting too. About 10-20 times per lap. It's not difficult, just takes a little time to get used to. It certainly takes a good year of solid practice to run with the upper pack.
What about tuning? What about it... I don't get it either :) Seriously... it's... different... from a car... but you get used to it. Just don't believe anyone saying any particular thing will fix the problem. Try making adjustments in both directions and see which one helps.
What motor should I get? Here's the breakdown... Honda: Most popular, most knowledge about them, most engine builders can build them to be the best. Lots of high end makes them good choices for long track. Easy to find parts for at motorcycle shops. Italian TM (Moto): Great low-end, especially stock. Almost like a lightly built motor out of the box. Parts are difficult and expensive to get. Yamaha: New and slowly becoming popular as engine builders pick up on it. Kawasaki: There's still some people playing with them and they work well in motocross.
Should I get a stock or built motor? For your first kart, I definitely recommend buying a stock motor. They're easier to drive (wider power band) and easier to start and maintain and it is possible to run them on pump gas if you have to. Built motors are finicky, and usually make a lot of top end power which makes them hard to keep in the powerband (rowing the gears).
What tires can/should I run? Whatever you want. Note that most kart series will specify a spec tire, sometimes a hard (SL tire like a YBN), but for autocross you can run any 5" or 6" tire. You should probably run something near the softer side of things, but your chassis and driving style may prefer something different. Note that the softest of tires will shred themselves on a hot concrete surface with 2 drivers (Topeka).
Who are you? We, collectively are the active participants in the F125 class. The original mailing list was founded by Paul Russell from San Diego. The original website was largely his idea, but implemented by me, Darren Madams.
What is the answer to life, the universe, and everything? 42.
What is the best way to get more information Subscribe to the F125 Mailing List and ask your questions there. Or visit a local track or shop and ask them... just be aware that opinions are like... well, you know.
Got another question, or perhaps an answer? E-mail me.