So, the compression on my bike has been gradually deteriorating form about 140psi down to 125psi. Also the top end started leaking oil and gradually the motor just became nasty. I decided to take the motor apart and rebuild it over the winter. Took the top end apart. Cylinder walls seem ok, no scoring or scratches. I can still see the previous cross hone on the cylinder walls.
Measured the cylinder bore and pistons. Here are the results:
Cylinder bore: 52.01-52.02 Manual calls for: 52.00 - 52.01 (recommends rebuild if 52.10)
Piston width: 51.60 Manual calls for: 51.55 - 51.60
I feel like I am just barely within spec. Is it worth it to go for a piston and ring kit? take it to a machinist to bore it out? maybe + 0.25?
Or should I just go with stock ring set, clean everything, hone the cylinders and put it all back together?
I do plan on servicing the head, cleaning everything, all ports, cleaning and lapping valves, replacing the springs...etc.
Hopefully this should bring my compression back up.
Your thoughts and recommendations are appreciated!
Here are some pics of the really dirty cylinder and head.
Measured the cylinder bore and pistons. Here are the results:
Cylinder bore: 52.01-52.02 Manual calls for: 52.00 - 52.01 (recommends rebuild if 52.10)
Piston width: 51.60 Manual calls for: 51.55 - 51.60
I feel like I am just barely within spec. Is it worth it to go for a piston and ring kit? take it to a machinist to bore it out? maybe + 0.25?
Or should I just go with stock ring set, clean everything, hone the cylinders and put it all back together?
I do plan on servicing the head, cleaning everything, all ports, cleaning and lapping valves, replacing the springs...etc.
Hopefully this should bring my compression back up.
Your thoughts and recommendations are appreciated!
Here are some pics of the really dirty cylinder and head.