If your Ski-Doo fitted with Mikuni 40mm TM flatslide carbs and the Ski-Doo DPM (Digital Performance Management) auto-adjust fuel system seems to be running rich, or does not deliver fuel economy as it should, check for broken plastic (nylon) float bowl vent fittings. These plastic elbows attach vent lines to the carbs, and when they are broken the float bowl pressure is no longer controlled by the DPM system due to their being exposed to atmospheric pressure. This almost always results in a rich running condition. These plastic vent fittings are not listed separately in Ski-Doo parts catalogs, forcing dealers to locate a complete â€œrackâ€ of carbs to rectify the problem.
Ski-Doo has smartly recognized the problem, and now offers these fittings separately. Order part # 404 128 800 to repair broken fittings and to eliminate the rich running condition it causes.