You should be able to pull out the largest bass boat no problem. I have used my Teryx to move my 26' Pontoon boat and I had to move it up a hill. Sounds like your belt has to much deflection. Mine was out of spec by the 20 hour service and my dealership did not check it even though I told them it was slipping. I know they did not because I put clear scotch magic tape on one of the bolts hoding down the inspection cover. So... I talked to Todd at Hunterworks who told me the CLutch Puller nad Spring compressor you need to adjust it myself. Also, Stakk who used to be here on TeryxHQ, not sure if he still is or not for sure but he gave me what has proven to be true for over 50 hours advice. He told me when I adjust it, that I should take out the thin shim on the driven pulley from the getgo. The belt will be a little tight at first but after the first 20 or so hours, it would be great and it has been. I run my Teryx HARD as it will go and race everyone I can find to race on the trails.
It is not that hard to do, I will be doing a video on installing a Dalton Clutch Kit and Cap very soon, but until then you can go to the link below and see some photos I took. If you don't have air tools it would be a little harder as you will need the special drive and driven pulley holders to remove the bolts from them. With an impact gun, you can hold them with your hand. Maybe hard to understand but I will show in the video.
Hope this helps.
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Teryx How-To and mountain riding Videos
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2008 Teryx LE - Muzzy's Exhaust - Dalton Clutch and OD Cover - FST Std Bore Kit - Dynatek Programmable CDI and Coils - Hunterworks Carb Kit - Walker Evans Shocks - PRP Seats and Crow Harnesses - UNI Filter with HW TPI Valves in Airbox - Bighorns - Unisteer PS - Baja 540C GPS - Coming soon, SDR 4 Seat Cage and Front Bumper