Okay, so personal watercraft aren’t cars, and they don’t go on roads. But they’re still hoontastic, internal combustion fun. Unfortunately, “standups,” the smallest, purest and most demanding type of personal watercraft are hearing voices telling them to walk toward the light. There are a number of riflemen standing before them in their firing squad:

• “Couches” — Standups were the original PWC and still have a uniquely intense army of rabid fanbois, but they lost the sales war to their easier to master, more versatile sit-down brethren. Today the two remaining standups in production (Kawasaki’s SXR800 and the Yamaha Super Jet) make up only a tiny fraction of PWC sales and have not seen major updates in years.
• The EPA — the two-stroke engines stand-ups rely on for their light weight and instant throttle response belch lots very eco-hostile hydrocarbons and greenhouse gasses and soot.
• The Economy — Yes, you can build a fatter, more complicated standup around a four-stroke engine. The European Hydrospace concern sold one for a few years, but their ski was big and expensive, sold in small numbers, and recently went belly-up. Boat and PWC sales have been some of the hardest hit during the current economic downturn, making a poor business case for enhanced new standup designs. Neither Yamaha nor Kawasaki have any current plans to develop four-stroke standups.
• Current Standup Riders— Two-strokes have a nifty feature: unlike four-strokes, they don’t seize if you turn them upside down while they’re running. Because of this, and two-strokes’ superior power-to-weight ratio, the freestyle PWC crowd who spend their time mastering all sorts of inverted tricks (which is the overwhelming majority of riders still sold on standups) don’t want a four-stroke standup. Most of them mod the heck out of their skis, and wouldn’t want the expense and complexity of a poppet-valve engine, either.