Tech Tuesday: 7 things to check on your kart

Kart prep is an ongoing thing but to get your season off to the best start you can’t beat a pre-season garage session. We’ve spoken to industry experts to get the last word in kart preparation after a winter lay-up.

1 Check for regulation changes

Every year drivers get caught out by what seem like petty rule changes and the worst case scenario is that it happens at the first round of a championship where you have to count any zero scores due to technical exclusions. So read through the MSA general karting regulations, your class regulations, and any club or championship supplementary regulations. Don’t let it be you who is chucked out for having your tyres rotating in the wrong direction!

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Most teams and kart shops are able to check your kart is straight on a jig

2 Check your chassis is straight

For better or worse, most modern frames are less stff than they used to be and more prone to bending from bouncing off kerbs or other karts, let alone more solid obstacles. This is why flat tables are a common sight outside team awnings. Many teams will check and straighten your frame for a reasonable fee, just ask!

3 Strip down and clean the kart and engine

You will want to do this more often than once a year, but a spring cleaning session is an ideal opportunity. Strip the whole kart down, including the removal of the rear axle assembly. Use a cleaning spray and make sure you get into the awkward corners, and if you’re using a pressure washer only do it after you have removed the parts with bearings. As you go along, check for cracks, worn cables and bolts and broken springs, and clean the brake discs with brake cleaner.

Laury Curran of Maranello Karts UK says “Clean the engine; the more you clean, the more you will find. Clean sprockets and chains in petrol or diesel and check they aren’t worn out then put the sprockets in order.”

A worn out chain will twist sideways and teeth on sprockets will become hooked.

Jamie Rush of R&S Motorsport says “Part of the clean that is important is to grease up the bearings, we usually use a product called Tri-Flow. It’s usually something a lot of people forget.”

At least once a year it us recommended to go over the entire kart replacing nuts and bolts, you can buy them in bulk from a local fastenings wholesaler.

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4 Check all accessible engine parts

Even if you can’t rebuild your own engine, for example in Rotax, there is plenty you can do to keep it in good condition. After you have cleaned it, take the engine apart as much as possible, using the manual that you can usually download or buy from the engine manufacturer. Many of the following need to be done as often as after each race or practice session, but get them all done in your pre-season prep session then you know where you’re starting from.

11-POINT ENGINE CHECKLIST

1 Clean and check the air filter, then clean after each wet race or practice. Clean with soap and water or brake cleaner.

2 Replace sump oil if using a four-stroke engine. You may need to do this as often as every meeting.

3 Check the starter cable if your engine has one.

4 Replace balance gear oil in engines such as the Rotax Max, and thereafter do after about five hours running.

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5 Replace gearbox oil and check it for metal particles by filtering through a clean white cloth. The drain plug should have a magnet that attracts metal swarf from normal gear wear and tear, but if you see an excessive amount get it checked by a specialist.

6 Check the clutch for wear, you’ll need special tools to loosen it and pull it off the shaft.

7 If you have a power valve it needs to be kept clean. Use something like Scotchbrite with carb or brake cleaner but not emery cloth as it will polish the valve too smooth and potentially make it illegal. Check it is fitted centrally and that it slides in and out easily.

8 Check the reed petals for chips at the edges or breaking up.

9 Check and replace starter motor brushes.

10 Check all electrical components are in good condition, including the earth wire from the ignition coil to the engine.

11 Check and replace exhaust wadding when it is burnt and brittle.

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5 Strip and service the brakes

Dean Golba of top TKM team DSG Racing says “Last time they were used chances are it was probably wet. Brakes don’t like moisture or dirt, they seize up and drag or bind on the disc. New pads, seals, fluid and a full bleed will make sure there are no issues and they are ready to go for the new season. Check which type of brake fluid your system should use, don’t mix DOT 5 Silicone based with DOT 5.1 Glycol Ether based.”

Using the wrong type of fluid can cause the seals to perish and lead to leakage and failure.

Laury adds “Learn how it comes apart and goes back together in case you need to do it in a hurry, and check brake discs for wear and cracks.”

And illustrating how important karting professionals think keeping your brakes in order is, Jamie had yet more tips “Always good to give the brakes a bleed, maybe re-kit and also de-glaze the pads and discs (especially gearbox and front brake classes).”

To de-glaze, rub the pads and discs with an emery cloth.

6 Check your datalogger or dash

“Something else is to clear the memory on the data logger and check all the sensors are functioning. Sometimes with the low temps and damp it can cause some problems,” says Jamie.

Also keep the cables and connectors in good condition and check that they aren’t pulled tight or chafing anywhere as this will eventually cause failures.

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7 Weigh your kart

Have you been munching mince pies or been on a new year health kick? Either way you may have some adjustments to make to your kart. If you are overweight, apart from the obvious solution, there are plenty of lightweight components to invest in such as floor trays, magnesium wheels if not already used, a seat or nuts and bolts.

You can also save weight by running a very small fuel tank. If you have the opposite problem, you should put some thought into where you put your lead, so try to use some corner weight scales and try to get the weight balance right.  If your corner weights vary on each side them you might be dealing with a twisted chassis which brings us back to point two. Driver-only weight also comes into it – several classes have minimum driver weights so if you’re a parent with a Cadet moving up to Juniors check they are eligible. If they’re underweight, you have two options; a steak-and-chips only diest for 3 months or a lead vest!

Learn from 40 years of experience

George Robinson, or Robinson Sport, who specialise in Rotax engines, has these great tips focused on Rotax engines in particular but they apply for anyone preparing a kart to go racing:

1)      A worn front sprocket is so often overlooked, as soon as the teeth start to look sharp or hooked, you are losing horsepower, the most efficient chain transmission is when all items are new or as good as new, that’s both sprockets and the chain.

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2)      If the in-line fuel filter shows any sign of dirt in the paper gauze—change it, it will have lost some of its efficiency and could be gradually starving the engine of fuel.

3)      Earth of the Ignition pack or Coil must be in good clean condition and the earth strap must not be too close to the High Tension Plug lead, these will arc across quite wide gaps particularly if wet and will cause misfires and possible damage to the ignition pack.

4)      Make sure that the engine mounting clamps are in good condition and grip the chassis tubes evenly and securely. Also the engine bolts that secure the mount. Vibration in this area will cause carburetion problems and probably crack the chassis as well…expensive !

5)      Throttle cables are ignored until either they snap or seize up. The Pedal stop should be adjusted so there is still a small amount of movement in the cable without it being tight as a Guitar string. Too tight and it breaks.

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Like this article? Then read more Tech Tuesday here:

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