Column

                                    by George Robinson

 British drivers at the Rotax World Finals gave a very good account of themselves with Jack Hawksworth coming home 2nd in Juniors as did Michael Simpson in the DD2 class. Martin Pierce did well to bring an almost undriveable kart to the flag in 10th place after an early incident in the Senior MAX Final.These positions were good enough to net the Nations Cup so well done guys! We are still waiting for that top step on the podium though, we’ll have to make a good fist of it next year when the World Finals are due to be held in the United Arab Emirates. There are definite plans to run a MAX Challenge qualifier in the UK again next year. The venue and date are being finalised at the moment.

Next year’s ‘O’ Plate meeting at Whilton Mill, scheduled for the end of September, has been moved to a date in mid August. The September date clashed with the final round of the Euro Challenge so this is a good solution all round. Whilton Mill Kart Club announced plans to extensively alter the circuit a little while ago and this is soon to become a reality. The circuit will have a faster mid section with more overtaking opportunities and less serious kerbs to worry about. These upgrades are set to put Whilton up there among the best in the country. The circuit is centrally situated near the M1 and A5 trunk roads and a stone’s throw from the conurbations of Northampton, Daventry and Milton Keynes. From the plans I have seen the new track looks as though it will suit the Rotax MAX and the DD2 extremely well.
2006 was a very good year for Rotax MAX and the engines have been superbly reliable. Their speed has gradually improved as well as more people, I believe, have learnt to achieve the best set-up. In 2005 at the Le Mans 24 hour race we used 12/84 gearing, this year it was 12/79 and could possibly have gone down another tooth. This is because the engines are now using more of the mid range where the horsepower is. This is better from all points of view. Engines are working much more efficiently, however it can be difficult to train drivers to be smooth and carry speed and some throttle through the corners.

This year I have run several teams in the Euro Endurance Championships that incorporate the French Championships and the Endurance Challenge. Rotax MAX engines have been more reliable and competitive than ever, the 100cc Formula A engines are still the ones to beat but the MAX gets ever closer, in fact winning the Endurance Challenge outright. The Challenge was perhaps not as competitive at the start of the season but really hotted up at the end with a good core of top drivers contesting the last round at Soucy on the 5th November.

The engines under my control covered a total of 220 hours of racing and not one starter motor, plastic gear or clutch back plate gave any trouble at all. That is not to say that we had a lot of other faults at all but these are the areas that traditionally were a cause for concern. Since it is now permitted to apply silicone to the carbon brush wire, fraying of the live wire is a thing of the past. The starter is also now a very reliable item. The body will sometimes crack, in spite of the protective ring that was introduced a couple of years ago. The ring does stop the risk of the body breaking away completely and of course it is still permitted to braze or weld up the crack. This is then a permanent repair and the starter should last almost indefinitely.

The clutch backplate is not in itself unreliable, however if the fulcrum bores of the clutch shoes are allowed to wear they will apply a bending moment on the fulcrum pin when they engage. Add in engine and trackvibration and this can be enough to break the pins off the backplate. If a careful watch is kept on the condition of the clutch shoes and some lubricant put onto the pins, breakages will be a thing of the past.

The plastic gear cluster is also very reliable if checked and maintained well. I always drain the oil and replenish after each day’s use. I also remove the gear cover to check the condition of the gears. Wear, if any, is usually in the teeth of the two large gears that drive the balance shaft. Any sign of scuffing or too much backlash indicates an immediate replacement of the balance gears. Having said that, these boys should last for at least 25 hours of racing if not more. While the gear cover is off it is worth checking the other gears as well. The drive gear very seldom gives any cause for concern, the idler should run freely on its shaft and the pump pinion should equally be in perfect condition. Rotate the pump pinion to check that it doesn’t feel notchy, it will probably be quite stiff to turn but it should be smooth. Check the gasket and copper washers on the fill and level screws and reassemble, replenishing with fresh oil, 50cc is the recommended quantity, I know that many people are using less but on your head be it if there is insufficient oil and a gear failure is the result.

The new airbox will be adopted as an alternative from January 1st. Unfortunately our tests have been spoilt by bad weather so I have nothing to report personally. However, at least two of the big teams have tried them and report no change in performance and I know this concurs with the Rotax factory view. The new airbox is much neater with a better bracket and the only items that need to be changed are the top and bottom housings as well as the bracket. Not an expensive exercise and available now.

If anyone has any subject matter that they would like to see covered in The MAX Column, I would be delighted to hear from them. After so many years of writing this every month I am aware that it could easily become stale. That is the last thing I want to happen and have offered to stop in the past and, although I am only aware of two readers, there was an outcry! I am not allowed to talk about sex, drugs or rock and roll although I have to admit to allowing a few glasses of red to slip down my throat to assist the little grey cells when writing.

Next year the Rotax MAX will have been around for 10 years, I wonder what would have happened to karting if it had never existed!