I've got a YM2200. the problem I'm having is that when I'm bush hogging after 15-20 min the temp is creeping up to 115 on the guage. I've flushed the raidator tightened the belt replaced the cap all with no luck on sloving the problem. I've have tried using a lower gear and mowing slower and it still over heats. do you think the problem could be in the water pump. should i try to rebuild?