I just bought a Rotax FR125 kart from Shockwave in October and because of the variable weather in Colorado this time of year I haven't gotten very much seat time yet so my experience is pretty limited. At The Track last Saturday however, I couldn't get my kart going due to a broken clutch spring and a weak battery. It got me thinking of how to best prepare for racing once the 2010 season starts so I am working on building up my spare parts inventory.

What tend to be the most common parts that fail on karts during race weekends?
Does anyone have a list of recommended replacment parts to keep on hand?

Thanks for your help, see you on the track.

If you keep one of these in the trailer you should have it covered:

HA! Blink has it covered.

Chains: They break, keep at least one new spare.
Sprockets: They wear out, old chains will chew them up, and new ones will too if you don't keep an eye on the chain tension.
Battery: One fully charged or 'new' spare.
Throttle cable: Cheap but important.
Brake cleaner-
WD40 (use as a cleaner, not as a lube)
Credit Card--get an extra one.

Talk to the shockwave guys, too. Pay one of them to go to the track with you.

No matter how many spares you carry with you, it'll be the one thing you didn't pack that will break. Get to know others and don't hesitate to ask for help or parts--and of course do the same for others. We once won a state championship race with a motor borrowed from a competitor. That's what makes the karting community so great, and this sport so rewarding.

Meanwhile, what I'd add to Kirk's list:
- spark plugs (if it won't start, one of the first things to swap)
- brake pads
- a box of miscellaneous nuts and bolts (metric of course)
- extra lead (if you need it). Scales are not consistent across tracks (or days), so you may need to add some at the last moment
- not really a "spare" part, but a range of jets (150 - 162 should suffice)
- duct tape!!

Ain't that the truth!

Joe, Kirk, and Brad (lol) all have good suggestions. As far as Rotax specific spares to pack....

- Clutch parts. Decent idea to keep a spare, complete clutch with you because you can snap the posts on the flywheel (happened to me twice this past season) and that makes for a bad day fast. At bare minimum i would keep a clutch rebuild kit on hand for when you do break springs, etc. Ideally...both.
- in-line Fuel filters
- Gaskets for the powervalve
- o-rings for the powervalve
- Exhaust springs
- clips for the carb needle (these are easy to lose...ask me how i know!)
- front (clutch drum) gears (these can get chewed up fast if your alignment is off)
- exhaust packing & stinger (every 10 hours...usually sooner)

The RTax is an amazingly reliable engine, but it does have chinks in its armor.

I also carry extra fuel hose and inline fuel filter as well as lots of zip-ties and Nylock nuts.

With Rotax, always carry a spare battery, and keep both it and your primary on a trickle charger (can get them cheap from Harbor Freight) when not in use. An online search (ekartingnews.com) will give you several battery models that work with Rotax and are OK for TAG, but not RMax Challenge, races.

All these guys had good lists. Heres my list:

Nuts and Bolts, most important IMO. I can give you a list of the more important ones for your kart if you want. A few items are:
M4x10 SHCS, M6x25 SHCS, M6x35 SHCS, M6x25 FHCS, M6 Nylock nuts, M6 Flat Washers, M8x25 SHCS, M8x30 SHCS, M8x65 SHCS, M8 Nylock nuts, M8 Metal Lock nuts, M8 Flat Washers, M10x35 SHCS, M14 Fine Thread Nut.

Battery, 2 chains, sprockets (front/rear), Clutch springs, Powervalve Gasket, Needle Clips, Gas Cap, Pedal Bearings, exhaust springs, pedal springs, zip ties, throttle cable, nose cone clamps, brake pads, motor mount clamp (for exhaust mount also), Rotax Clutch Nut (M12x1 Nut), King Pin Bolt, Tie Rod Ends.

Anything you don't have we will have on board the truck at most races. We have a few schedule conflicts this year and won't be able to make it to every race but we will try to be at most. If you plan on doing RMAX Challenge stuff that is where we will be for sure.

As a soon to be newbie here, recently bought a CRG w/ Leopard, let me say this is the best thread I've seen...needs to be a stickie...thanks in advance for the help you're giving

This is great information and will definitely help me get started. Just a few months into karting and I am impressed by the camaraderie. More sports should be like this.

Thanks everyone for their replies and suggestions.

If you race at IMI all you need is your credit card. Brad has everything you might need in his shop

Edited for accuracy, Greg. :

Extra Carb parts, and carb rebuild kits, lol my leopard ran liek crap last week, replaced some stuff, at the track thanks to Schermahorn, and then elbow on the carb broke off and we had to get one of those, so keep extra carb parts!

Safety wire.