I have a 1988 YFM225 Moto 4 that I purchased new back then. It still runs as good today as it ever did. I go everywhere the big boys go (well, around some of it) I have noticed a clicking lately that sounds like a ujoint. Has anyone ever replace the ujoint on one of these?and if so, what kind of undertaking is it? Thanks

It has an enclosed disc rear brake, and I have serviced it and adjusted it. The clicking comes from rear, if I get on a hill and coast backwards. Have not noticed it any other time.