I have a 2009 xp 550 will mudlite xtp tires fit on the quad the front tires are 27/9/14 back tires are 27\11/14 some help would be greatley appreciated.
Yes they will fit, but the rear will rub on the rear sway bar and need spacers. Or you can very carefully bend the rear sway bar until you have the proper clearance, there are complete instructions on how to do the sway bar (mod) or bend on Highlifter forums. This is the same with pretty much all wider tires on the rear of the XP's unless you go with aftermarket rims.
If you get aftermarket rims with a (dish) or different offset the tires will be just fine.
Hope this helps.