Riding Rob Flores triple cylinder SX-R is a unique experience. The ex-factory rider has been researching the ultimate set up for years and has perfected it for racing use.

Over the years we have seen many changes to the IJSBA rule book. The most interesting one came up in the beginning of this decade with the prohibition of the modified class. The main idea behind the particular decision was to lower the overall cost of the race craft and to give the opportunity to lower budget teams and privateers to build fast race craft. On the other hand this rule meant bad news for the aftermarket companies that perfected special parts for race use. By the middle of the decade the cost of a Superstock race craft rose substantially and its reliability was a serious issue. In the last two years the rules have once again been altered a lot and this year the Open Class is actually “wide” Open, enabling race craft builders to use aftermarket hulls, bigger engines etc.

I guess that ex-factory rider Rob Flores and owner of Raceski.com probably had foreseen all these changes coming and had been working for years on this triple cylinder equipped Kawasaki Jet Ski. Initially he placed the STX engine inside the engine compartment of the SXi Pro and then he installed it in the more stable and race oriented SX-R hull. There are many issues with such a project although fitting the engine and the right drive shaft was much easier than it sounds. The philosophy behind using the triple cylinder engine was that you actually start with a larger in displacement engine that, with a mild tune, would be able to produce more than 160hp without being stressed and also have a wider power band.

Flores had focused his attention on the weight distribution, since the heavier engine tends to alter the handling a lot and the overall performance of a small craft. Therefore, he decided to relocate the electric box at the right front side, between the hull and the fuel tank. This allowed him to place the engine further back by using a shorter drive shaft. Actually the magneto cover rests the same distance from the tank as on the SX-R’s twin engine.

Setting up the whole balance of the craft required additional touches on the hull. Rob spent countless hours testing sponsons and ride plates in order to find the best overall balance and to achieve the sharp handling characteristics. Bearing in mind that the later will not be affected by the extra weight of the triple engine.

The front sponsons were a must in order to create a larger patch on the water surface though the tricky parts are the handmade aluminium rear sponsons. Those are not simply a set of blades as everyone would have thought. They have an L-Shape design and Rob has placed them in a particular angle.

The concept behind this design is similar to the plastic rear sponsons that Kawasaki used on the SXi Pro during the late nineties.

The particular triple SX-R engine unleashes 140hp in its stock format. The engine was not heavily modified. The cylinder and case porting was done by Tim Judge, though the compression ratio was kept at a reasonable level and the cranking compression rose to 125psi in order to keep using pump gas and not race gas.

The stock carbs were replaced by a set of Novi’s, the first generation ones, which featured an aftermarket air filter on the top. Additionally, the induction was equipped with a triple set of R&D M16 reed reeds.

The most interesting part of this triple engine is the ECU and it is not something you can buy off the shelf. It is a programmable Mitsubishi ECU that comes straight from Factory Kawasaki Jet Ski Team.

As far as I know there are not many people capable of getting things out of this Team unless of course they buy a complete race craft. Rob informed me that this ECU plays a key role in the linear performance of this engine.

The exhaust set up is also very interesting. Flores kept the stock chamber, but modified it by altering the cooling system routine. Also, he did not use the SX-R’s waterbox and through hull silencer. Instead he added a small muffler and fitted a new through hull silencer on the left hand side of the hull. In order to fully control the exhaust temperature he used two water outlets with spring valves and an electronic water injection system. All these parameters play a key role to the overall performance of the engine as well as the linear horsepower propagation.

The fact is that the pump set up is not easy-come-easy-go on this project. There are many things that have to be taken into account especially if you want to be able to race this craft for the whole distance.

Therefore, he tested different nozzle set ups in order to achieve the best compromise between good acceleration and top speed.

Show Time

Most people would think that if you grab the throttle of this SX-R you will fly like Superman. Well, this was not the initial intention of Rob Flores when he arranged this particular set up. He simply wanted to make a fast and reliable race craft to run on pump fuel. So if you bear in mind the performance of an STX you will realise that this one performes like a regular tune up. As soon as I was on board, I flicked the throttle a couple of times in order to feel the engine response and how crisp it was at low rpm before I would ride it in race mode. The funny think was that this engine was actually accelerating so smoothly that I could hardly believe that I was riding a tuned up triple two-stroke engine, this was the magic thing about this race craft. The triple SX-R was accelerating strongly but at the same time in a very linear manner and the power band was full from idle to the rev limit. There is no hesitation from off to full throttle. The engine was crisp enough without any black spots of hesitation. There was enough power to get you out of the buoy without losing time and without wearing you out. I had two sessions on this race craft and felt I could practise all day long.

Handling wise the set up was extremely good and I am sure that it required lots of testing to perfect it. The first thing I noticed was how well balanced this triple SX-R was. The craft was not hoping around or feeling heavy while I was flicking from one side to the other. Also, it was not getting heavy on the nose when I was decelerating in order to go round the buoy. Additionally, it had shown no tendency to sub while steering aggressively. Personally I believe this is the best part of the work Flores had done on this triple SX-R. The pump hooked up very well no matter how hard I was on the gas.

I tested the craft with a Craftsman’s Movement ride plate, the Takenosita replica, which provides a peculiar feeling when you prepare to lean over and go round the buoy.

For rough water conditions, as at the World Finals Pro day, Flores uses a modified stock SX-R plate. For my personal choice I would have preferred a shorter pole, stiffer on the bottom and with a looser steering system.

On the other hand I could not criticize some else’s preferences, especially if he is an ex-factory rider.

I think Flores is the only Pro rider who still uses a stock pole with a stock steering system and Kawasaki’s trigger throttle lever.

I have been watching Rob Flores for the past four years running this triple cylinder ski and every year he said that when he got it right I could ride it. It was worth the anticipation because the result was so good. I couldn’t have been more impressed if it was a mean, very fast, machine especially as the crucial thing is to be able to ride it. Rob Flores is a very experienced rider and I respect his knowledge and craftsmanship behind this entire project. I am sure that getting more power out of this engine is not very difficult and I believe that next year we will be allowed to use aftermarket fuel tanks, it will be a challenge to update this project. Fuel consumption is an issue with this triple engine and, in line with 2010 rules, you would probably run out of gas with a faster.