Belt slipping

[Nemy]

I have a xw2300-60. When I go through tall grass, which is what I am mowing most of the time, it seems like the belt is slipping. What happens is the blades stop turning but the engine does not slow down. I thought at one time the engine would slow down when I went through tall grass. I have tightened the tension spring several times and that seem to help a little. Just wondering if this is a sign that I need new belts or is it another problem. The belts do not look that worn.

Also, how do I know which belt to replace, or should I replace them all. I probably have about 300 hours on the belts

Any help would be appreciated

[DC Service]

There is a belt adjustment for your engine-to-deck belt.There is a threaded linkage rod under the floor pan.The spring should measure 1 3/4 " when the deck is engaged.The deck belt is self adjusting(spring loaded idler).Just make sure you lube all the fittings,so the parts won't bind.This should cure your problem.Your local dealer can also do this for you. Good luck. :)