Spun belt on hill, with 1k tires, suggestions?

Got a 16′ 900-4. Just bolted up a set of 29" bighorn, 1k take offs. First time out, climbing a hill, from a stop I spun the belt. Hill had some ledges on it, and tires had good traction. I was trying to be easy on it and not give it to much throttle, to not spin the tires, however I heard the belt spin and smelled it. I was told they don’t have a clutch kit out for the 16’s. Anyone had any problems spinning belts on these. Anyone do much crawling or hill climbing with theres. I bought a 900 becausr of the A-arm set up so I could climb and ride trails with it. Hate that it won’t pull. Makes me think the new low gear may be a little to high. My dads ’12 xp-4 had no problems. Figured Id get yalls opinions on it.