Running 1/4” blades on a machine designed to be fitted with 1/8” blades adds extra drag on the engine as well.

If the underside of the deck is not smooth, the grass will not circulate very well. Make sure the uplift on your blades are not worn down. If they are worn down, the blades should have been discarded long ago. Keep your blades sharp and balanced.I have a 17 year old YS4500 mower. I have about 2 acres of grass to cut. I am using mulching blades. My problem is that the deck gets a buildup of grass clippings. I know that if the grass is wet this buildup will always happen. But this happens even of the grass is fairly dry.
The pix below was after cutting about one acre of slightly wet grass. But like I said this happens wet or dry.
Am I just needing to clean the deck after every time that I cut the grass?View attachment 66376View attachment 66377