Before you haul the carb off and start playing inside do the simple things first. Is there any kind of play in the throttle shaft at the bushings? Is the throttle butterfly valve properly round inside the carb throat or are there square ding marks on the outer edges where the valve meets the throttle shaft? Do you see any sort of fluid leak or seepage around the throttle shaft seals? If yes to any of these you need a throttle shaft rebuild kit. If the ski ran well any time in the past but has suddenly started doing this possible lean running condition, start with checking for loose or sloppy moveable hardware first. Just remember, all the air must come in through the top of the carb only, if there are any leaks anywhere, you will never tune that engine or tune it well.
You say it's a 94 61x engine, do you know how old the gaskets, crank seals and bearings are? If it's an original 61x engine then it would be a 27 year old original engine, crank seals are a wear item and have a shelf life...27 years is really pushing it on a 2-stroke. Those seals could be spent and/or the crank bearings. With worn crank bearings the crank will be allowed to travel up and down inside the bearings opening up an air gap between the crank seals and the crank. This will also make for a lean running condition that will never be tuned out.
