I have a ’98 Ski-Doo Formula DLX 583. I went for a 5-mile ride last winter and was going 60 mph when the sled started to bog as if it had a fouled plug. I replaced the plugs. It ran like it was starving for fuel. For a half mile I couldn’t get over 20 mph running at 5000 rpm. Then all of a sudden, it broke loose and allowed me to go 60 again for few miles, and then started acting funny again. I’ve cleaned the carbs. Compression is 125 on each cylinder. Took the sled out again and had same problems.
Everyone has said it’s a fuel issue. This year I decided to replace the carbs and add an in-line fuel filter. I took it out last weekend and it ran awesome for 5 miles. Then it started acting up again. I checked for air leaks, but didn’t find any. Spark plugs were darker brown and a little on the wet side. I took it out again yesterday with similar issues. It ran awesome for first few miles. The sled definitely runs the best cold. Then when it gets warmer, it only can go 2-3 miles before acting funny. Any advice? – sdorn2006
If you believe it to be a fuel-related issue, then start at the source (fuel pickup in tank). Check the in-tank supply line and filter; see if it is still attached to the through fitting on the tank and that the filter on the end is clean. Next look at the fuel shut-off valve and make sure it flows correctly. Then move on to the fuel pump. Check the diaphragms and verify that the pulse line has good vacuum to actuate the pump diaphragms. Then check the carbs. Make sure they are clean and jetted correctly (on rotary valve motors there is a left and right carb; if they are backwards the jetting will be wrong). Next check the motor by testing compression and leak down, making sure the rotary valve is operating correctly and in time. Confirm both RAVE valves operate correctly and the exhaust has no weird restrictions. That should be about all there is! Good luck!
- Todd Guthrie, Dynatek Racing