- Joined
- Dec 11, 2008
- Messages
- 198
Last night I removed my cylinders and head to bore to .020. The head I removed is a replacement for the original that had the exhaust thread inserts pull out. I had gotten this head of Ebay, sent it to a friend that pronounced it good to go, so reused my rockers, etc, and just lapped new valves in it.
When I replaced the head, I had also pulled the cylinders to inspect, and found the standard pistons had to much clearance between the rings and groove, about .010 or more. The bores were close to the wear limit, but I went back with standard pistons just to get a few more miles before a rebore. Last summer, it would smoke on start up, and following riders would tell me it would smoke some on deceleration.as part of my prep for the INOA national, I thought I'd rebore and fix a few other small items.
However, when I pulled the head, the colour in the combustion chambers looks ok, but looking down the exhaust ports, things don't look so good. The left side has a brown dry lining in it, but the right side looks like it has been ceramic coated, black and glossy.
Left port;
Right port;
Terrible pics, I know.
The head of both valves look ok, dusty brown in appearance, but the port on the right is glossy. Oil leaking around the guide perhaps?
When I replaced the head, I had also pulled the cylinders to inspect, and found the standard pistons had to much clearance between the rings and groove, about .010 or more. The bores were close to the wear limit, but I went back with standard pistons just to get a few more miles before a rebore. Last summer, it would smoke on start up, and following riders would tell me it would smoke some on deceleration.as part of my prep for the INOA national, I thought I'd rebore and fix a few other small items.
However, when I pulled the head, the colour in the combustion chambers looks ok, but looking down the exhaust ports, things don't look so good. The left side has a brown dry lining in it, but the right side looks like it has been ceramic coated, black and glossy.
Left port;
Right port;
Terrible pics, I know.
The head of both valves look ok, dusty brown in appearance, but the port on the right is glossy. Oil leaking around the guide perhaps?