Sunday, Jan 5, 2014 [25,724 miles]
After SMBC breakfast this morning I took a closer look at valves and pushrods. No pictures, but all 4 pushrods look to be straight. No wobbles noticed when rolling them along a flat surface (a granite counter top).
remove valves from left head
intake springs removed
The exhaust valve slid out of its guide once the keeper and springs were removed. The intake valve had a slight burr around the keeper channels. I dressed the top of the valve with a fine stone until it slid easily out of the guide, too. The valve looks good. I chucked it in a drill and spun it to check for any bend or wobble. It’s straight.
remove valves from right head
other exhaust valve
intake valve needs dressing
The valves in the right heaad were a mirror image of those in the left head. You can see where the intake valve stopped sliding before I dressed it with the stone. Once removed I gave it the drill test, too. Straight.
The valves and valve seats need some touch up work. Might need new valves as there isn’t much meat left for a re-grind. And the right head need the exhaust side head screw channels reamed. Next up is a closer look at the pistons.
Monday, Jan 6 2014 [25,724 miles]
remove left cylinder and piston
Loosen base nuts
Today I pulled the left cylinder and piston. No particular reason for starting on the left side.
While the piston was cooling I checked the cylinder. It is round, more or less. The top and bottom measure 73 mm top-to-bottom and front-to-back. The center of the cylinder measures a bit more than .01 mm (.0005”) wider than the top and bottom.
I gave the pistons a light cleaning to get a better look at the damage. These pistons will not go back in the bike. Too bad as other than the damage to the crown they look good and still measure at the skirts to the 72.92 mm marked on their crown.
valve spring comparison
Old left, new right
Inner spring: old left, new right
Old left, new right
For the curious; a comparison of old and new valve springs. The old outer spring is shorter than the new. Surprisingly the old inner spring is longer than the new. The test is one suggested by Duane: put the two spring sets back-to-back and compress. At this point I’m guestimating the springs were about one third compressed. The old set had compressed to 34 mm while the new set had only compressed to 36mm.