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Here you can find some advices I didn’t mention in others chapters, but which are very useful when you have to prepare your kart.

Ballast

In order to run in official races, a minimum weight is needed and it’s 145 kg for 100 cc category and 165 kg for 125 cc. This weight is the sum of the pilot (completely dressed) and the kart. Generally, the kart has a weight around 63-70 kg (it depends on the chassis, on the petrol tank and on other less important factors). Considering for example a kart weight of 65 kg, we can calculate that in order of having a total weight of 145 kg, you still have 80 kg available. If your body weight is less than 80 kg, you need to add a ballast in order of reaching the minimum weight required. It’s advisable having a kilo more than the minimum, since during the race, especially if the race is a long one, you will burn petrol and you will loose some body water since you sweat (you can loose to half kilo).

Generally, in order of calculating the necessary needed weight, you have to perform the following steps:

filling the petrol tank for about half of the total capacity; that’s because on a basis of 6 litres, about 3 litres will be lost, considering a 15 – lap race (and 3 litres, it means about 2,3 - 2,5 kg);
weighing the kart (the kart ready for the race, with wheels and all things needed) and the pilot (you can do this operation separately for the kart and for the pilot, or both together if you have a big weighing machine (in the first case you have to sum 2 weights, having the pilot dressed for the race);
then you have to execute the following calculation (MIN REQUESTED WEIGHT) - (KART WEIGHT + PILOT) and you obtain the ballast which has to be put on the kart. If you are overweight, you are not going to have any problems since you can run with less petrol, instead of beginning with a full petrol tank. If you are underweight, you will be disadvantaged;
once you have obtained the ballast to be assembled on your kart, it’s better putting a kilo more (you are not going to have any “performance” difference) and you will feel more confident. Now, you have to buy it: it’s sold for the price of about 7 euro per kilo (it’s a bit expansive…) and it consists of lead blocks of 1, 2, 3, 4 kg (there are no blocks weighing more than 4 kg). If you need to assemble a total weight of 5 kilos, you can put a 4 kg block + a 1 kg block.

In order of assembling the ballast, the official regulation affirms the weight can be put wherever you want on the kart, but it has to be fixed to the chassis through some screws. And here we find a contradiction: as a first thing most of the pilots put the ballast on the seat (which is not part of the chassis) and then, for example, it’s not taken into account the screws welding, even if very strong. It’s not said the weight has to be officially approved. So you could do it by yourself and assemble it thanks to some screws. I ran a race with a 8-kilo weight (and it was even too much, because a 5-kilo was enough… and now I’ve just assembled a 4-kilo one) like “handicraft” (it was a kind of big cylinder), welded to the iron cable, which is not part of the chassis, where the lateral bumpers are attached; during checks nobody said a word about it, even if a guy looking at it he was perplexed…. He said it was dangerous (but I don’t’ believe such a thing) and could unbalance the kart (and it was likely to be…).

Coming back to the topic concerning the assembly, the advice usually given is to assemble it to the seat, on the opposite side of the engine, to counterbalance the total weights balancing. This is valid until a certain weight, and over it you should start putting a kilo on the right side and a kilo on the left side; well until 4 kilos you can assemble it on the right side, in the bottom seat part (in the corner, close to the “fanny...”), over the 4 kilos, add 1 kg on the right, 1 on the left, 1 on the right, 1 on the left and so on.

The assembly is shown in the picture: the protruding screws are external, while the flat ones are internal. That is exactly what the reason would say… since they are close to your “fanny” left side… Screws do not have to be tightened so much, since you could break the seat; you have to tighten them, but not to exaggerate. Since you do not tighten the screws too much, you need the anti-unscrewing washers, which are usually given together with the ballast and the assembly screws.

Car body and screws

Plastic parts of your kart do not usually require a specific attention, as well as the plate where you put feet, the petrol tank, etc.

Concerning the bumpers, they have to be replaced just in case of break-up or in case of important warping, generally after accidents. The same thing has to be done for the plate under your feet; what is important is that it has to be well screwed to the chassis. Vibrations could unscrew the screws and then you will have a problem: the plastic parts start trembling and they cause a certain discomfort during driving and they become potentially dangerous: they could easily fly away, if they are only attached by one screw partially unscrewed… In addition to this, in case of accident, they are not going to be reliable anymore, if they are not very well fixed. So, sometimes you really need to check the screws. In relation to the screws, they have to be the same kind of screws (and it’s not just for aesthetical purposes…), so you need only one type of wrench to tighten all screws. If you have all different screws, you will probably waist half hour to find the right wrench and to change it in relation with the screws… and you will get very nervous…, etc. So if you loose one screw, it’s better replacing it with a screw of the same type, and if you cannot find another screw of the same type, it’s advisable replacing all screws (even if because screw + bolt + washer cost about 0,5 euro). Still concerning screws: if they are rusted or ruined, it’s better replacing them. So you can avoid to have a rusted screw embedded inside, or to break because too weak… And finally it’s better having the kart with the same shining screws.

Stickers and cleaning

There are no special restrictions in using stickers on the kart, on the helmet or other, you should just use a certain care in removing these stickers from the helmet, because it could be ruined. So you can stick pretty much whatever you want in order of having an attractive kart, of sponsoring it or doing a kind of personal advertising …. I can advice you not to use normal paper or adhesive paper, because if wet it can be ruined and become very “ugly”, and even without any water it easily becomes not nice…
If you want to stick something, it’s better printing out decorations on a specific paper (maybe in a typing/ copying office); I can tell you this, after a personal experience.

To clean plastics parts, you can use specific products: I personally believe the thinner is able to make the plastic parts well shining. Unfortunately they have the problem to get dirty quite soon (in particular mine, which should be of a bright black, but few grams of dust are enough to remove all brightness). With the same product you can also clean the entire chassis, even if on the mechanical parts close to the engine area (the whole back group) it would be better using some petrol and only later some thinner. To clean by using the petrol (without any oil), a small tank can be filled with some petrol and then using a small brush, which can then be used to clean and brush.

Some parts (as the back axle) made by iron, can rust on their surface and they can be cleaned only by an iron brush and with some elbow-grease. Only later you can bright them.

Girdless, cable, pedal, accelerator spring

It could often happen the throttle valve of the accelerator cannot close in a proper way, and it could happen because the accelerator cable doesn’t run well inside the girdless. A least friction is always tolerated, but it should be reduced as much as you can. The perfect situation would be, in order of closing the throttle valve, not to have the necessity of an external spring (which is shown here on the left), or better to have the spring only for safety reasons. This problem could be caused not only by a bad cable/ girdless flowing, but even by a not proper angle between the cable and the hole of the carburetor’s iron plate (bottom left in the picture). So it has to arrive well straight. Another cause is the girdless is broken, and in that point it bows, creating an angle which allows a certain friction.

You can increase the flow, by filling the girdless with some oil and greasing the cable. Concerning this cable: you can buy it in a karting club or in a regular bikes shop (or also at the supermarket); in this last case it’s better having a spare cable, not the brake’s one (thicker and rougher). The regular price is quite cheap (around 2-2,5 euro), so you can really replace it as soon as you need. These cables have on one side a kind of lock, on the other side they don’t: so let the lock enters the part of the carburetor, let it passes in the girdless, let it goes out, passes in the pedal and then roll up the remained part, maybe rolling up it a insulator. In order of blocking the cable, you can use some small cylindrical clamps with a screw on the top to close a small hole where the cable flows. And hold tightly after cleaning the cable, removing all grease. Do not cut the additional remained cable, since it could frays!

Be very careful the “recall” spring doesn’t “jump away”, because you could be in a situation of having the accelerator all tightened during a detached. An alternative option is to put an internal spring, which is usually more resistant: it’s called internal spring because it is put between the gold coloured plate (in the picture it’s a dirty and light gold coloured) and the small carburetor “ball” (of course before let the thread pass; it has to be put later and it will act like a block). Anyhow, the external spring is generally ok. In some extreme and emergency situations, you can assemble both springs, but only in real emergency situations! For example if you don’t’ have a cable and you have to run with your kart in 5 minutes!

A last thing: the pedal block doesn’t have to be obtained by the throttle valve which doesn’t rotate anymore, but by the special screw put in front of the accelerator pedal. That’s because, in the first case, the throttle valve would be forced too much and there’s the risk of ruining the rotating block, which could become not very stable (and it would start tremble) So, screw the screw in a way of blocking the pedal just before the throttle valve finishes its turn (the throttle valve turn will stop in a position above the 180° - where there’s the max rpm – so you don’t loose anything).

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