My kids just got a used 2003 LT80. The previous owner installed a FMF pipe (I believe without jetting it). I just pulled the plug and it is black as coal... I don't believe any airbox mods have been made. It idles a little rough and the acceleration isn't where I think it should be. What jet would you folks recommend? Most of the riding is done at or around sea level. Also, for the first couple of months I will be using the governor... Thank you for your assistance in advance.

 

I'd go down to a 90 main jet.

 

Thank you for the info. I just pick up a 87.5 and a 90. I have read several of your posts, you know what you're talking about.