Hi all. Thanks in advance for the tips. I’m in need of some knowledge. Always done arrive and drive, but about to jump into something more serious. Rotax max 125.
I don’t have much mechanical knowledge and I’m wondering what tips for general maintenance and performance you could give? I live in Taiwan but for the most part things are similar to the UK.
Are there any must do’s, or definitely don’ts that I should be on top of? What’s your best slice of advice?
Once again, thanks for any help.
Welcome, Charlie!
Here’s a quick list of best practices that I try to adhere to:
Cleaning- clean and inspect (cleaning allows you to efficiently inspect at the same time) the kart as often as possible. After every day at the very least, and certainly before all critical sessions if you want to be on top of it. You’ll find that you may catch little things during cleaning that you may miss in a quick visual-only inspection, e.g. loose bolts, etc.
Chain lubrication- after every session first thing when you get back to your pit.
Engine- clean and inspect key components before and after each race weekend. These could include: spark plug (make sure it’s not getting overly wet/fouled), power valve (Rotax specific- clean after each day, or before each critical sesssion), exhaust packing (Rotax/shifter specific- most teams used to always use a sticker applied to the bend side of the exhaust silencer. When the sticker starts to burn/melt away, time to change packing.), carburetor (clean after each weekend, replace gaskets and needle/seat every few weekends), clutch (inspect/clean after each weekend- hit clutch shoes with sand paper if they are glazing over), gearbox oil (where applicable- change per manufacturer recommended interval), and of course be sure to have top and bottom end parts replaced per manufacturer recommended intervals (find an engine shop that you trust and stick with them…this is a relationship you’ll be glad you’ve built!).
Front end alignment- if you’re making changes to the kart often, then it’s likely you’ll be doing this anyways, otherwise I would typically check front end alignment before or after each day (toe, camber, sweep, check kingpins for straightness, check steering shaft for straightness).
Bearings- keep these lubricated regularly with a product such as Tri-Flow. This would include axle bearings, rose joints, spindles (kingpin area, and slide area for front brake applications), steering shaft, steering column (not really a bearing, but you’ll want to ensure the steering isn’t in a bind), wheels if using direct spindle mount fronts.
Seat- regularly inspect for cracks/breaks. You shouldn’t really run into this on the underside, provided your seat is mounted flush with the frame rails, or above. If mounted below then it may wear through and require a fiberglass repair. Other areas prone to breakage would the the top of the seat in the middle (top of where it meets your spine), and lower mounting points. The seat is a very important part of the chassis dynamics, so it’s important that it’s mounted correctly (without being in a bind), and that you repair/replace if damage occurs.
Frame- inspect for cracks, usually around the welds towards the rear of the kart.
Fuel- only mix with oil based on what you’ll need for the day/weekend. Old fuel/oil isn’t ideal, so also be sure to drain from your kart’s fuel tank if it’s going to be unused for a while. What to do with old fuel, you ask? Lawn mower, snow blower, etc.
Other miscellaneous bits- you’ll find that certain parts may be prone to coming loose more often than others, the rear bumper being one example. It may be prudent to double-nut these items and/or install a strong zip tie or cable to act as a fail safe. Nothing worse than getting DQ’d due to a rear bumper bolt coming loose, causing the thing to drag behind the kart.
I’m sure others will chime in with additional ideas, but hopefully this is helpful to some degree.
Thanks for this I’m in same position as the thread started except lo206
This is fantastic advice. Thanks a lot!
Add skid plates to bottom of chassis.
Remove transponder and mychron and bring home to charge. If you are in a TAG, starter batt as well. Gopro still mounted? Don’t forget the vape/phone you left on floorpan. Go give Gary back his 10mm socket. 
Read up on the rotax here. This is everything you need to know to keep the rotax happy
cheers. This is a big help.
Does the alignment change over normal running even if the kart has not had any contact?
I find that my toe settings are usually out of whack after a race no matter what happens. Maybe I am not tightening the tie rods tight enough?
It may shift slightly if there is slop in your kingpin assemblies, but the toe generally shouldn’t change more than 0.5mm/side.
If the center point is changing slightly each time you check it, you could have a little variance.
If it changes more than that what is likely the cause? Tie rods too loose?
Something loose or bent.
When you go to readjust the toe, are the tie rods tight or loose?
That’s a good question, they are tight. I made a note to double check alignment after each session this weekend.
Check alignment and just make a note of the threads on the tie-rods so you can tell if they moved. But if they are tight when you come it, they probably didn’t move.
Slack or tension somewhere when you tighten everything down can cause the geometry to change once the kart gets loaded in a race and things settle in, so that could be it as well.