I have a 2010 rzr s that I bought used last year, seemed to run stronger the first couple rides then ran rough for a few minutes and cleared up but just seems to not run as strong as it did. It has a yoshi full exhaust, snorkels, and dynatek piggyback ecu that was on it when I got it so no idea how its tuned. I did a basic tune up, new plugs, clean air filter, new fluids and ran diagnostics and compression test. I got a code 26 which looks like a bs code from reading on here and the compression was at the low end of good per the factory manual. I have changed the belt thinking maybe it was slipping but no change and it has been reliable on rides but still seems down on power. will only get to about 45 or 50 mph unless you have a ton of room and slight down hill will finally creep up around 60 mph.
Where should I start now? Is there a fuel filter I can change? Anywhere I can send the dynatek to check the tune or have adjusted since I don’t have the software or cable to hook up to it.
Utah RZR Rentals

whence