sbtm
XS650 Enthusiast
I have an 80 xs650 thats been mostly sitting for at least 15 years. When I bought it 5 years ago, it started and smoked out of the right side. Recently a friend and I have been trying to piece it together for him to ride.
I did a compression test today, the left was 140 cold, 120 hot. The right (the smoker) was 130 cold and 120 hot. I am suspecting valve seals at this point. I went ahead and pulled the engine and head and jugs.
The right piston skirt had some scoring, the cylinder is smooth. The right jug (outside) and piston arm look like they have been cooked... they are pretty dark. I also gapped the piston/cyl clearance... its at least .007in on each cyl. I suppose I could check the rings to see if theyre oversized or not (they looked in really good shape), i believe the pistons are stock.
So, since I have decent compression does that eliminate bad rings/pistons? I am going to replace the valve stem seals since there is just so much oil.
Any thoughts?
I did a compression test today, the left was 140 cold, 120 hot. The right (the smoker) was 130 cold and 120 hot. I am suspecting valve seals at this point. I went ahead and pulled the engine and head and jugs.
The right piston skirt had some scoring, the cylinder is smooth. The right jug (outside) and piston arm look like they have been cooked... they are pretty dark. I also gapped the piston/cyl clearance... its at least .007in on each cyl. I suppose I could check the rings to see if theyre oversized or not (they looked in really good shape), i believe the pistons are stock.
So, since I have decent compression does that eliminate bad rings/pistons? I am going to replace the valve stem seals since there is just so much oil.
Any thoughts?