Model# 927988 Serial# 06071482
I will grease the arm and check the other pulleys. If that doesn't work I will replace the spring I guess. I have put that belt on numerous times now with it coming off while mowing, so I can take it off and inspect in no time. Everything sure is hot under there, burnt my forearm a few times putting belt back on..........
The spring does pulsate like you are saying, very bad. I always were ear plugs and it's loud.