The cylinder head has been off the bike for a while now to determine the reason for the loss of compression in the No. 3 cylinder. In previous posts about this issue, Valves, it was determined that the No. 3 intake valve was bent when the cam chain guide broke and the timing jumped. Now that the cylinder head has been cleaned and painted it is time to reinstall the valves with a new intake valve ready to go for the No. 3 cylinder.
The first item was to install the new valve stem seals on the eight valve guides.
I used a 10mm socket on a hex driver handle to push the seal on to each valve stem to reach down to the valve guide and not push on the seal.
From previous work cleaning the combustion chambers with the valves still installed it was confirmed that the intake valve in the No. 3 cylinder was not seating properly since the cleaning solution was leaking past the valve and coming out of the intake port. I wanted to do something similar with the install process to make sure that the valves were seating properly, but did not want to make a mess of the newly painted cylinder head. I tried shining a flash light through the intake and exhaust ports which showed very clearly if the valves were seated properly.
As a worst case scenario, this is what was seen with the bent valve in the No. 3 cylinder. The intake valve is to the top side of the picture.
Of course, I can’t show a picture of a correctly seated valve, it would just be black.
All in all, the four exhaust valves seated very well as is and the 3 existing intake valves were also pretty good. A little light was escaping on the intake valves, but light pressure on the valve corrected that. Much less pressure the the valve springs will exert to hold the valves closed. The new valve, as expected, needed a little more work to seat in the worn valve seat. A few turns of the valve with same lapping compound and lapping sticks did the trick.
To complete the valve installation it was then just the repetitive process of installing the springs, spring retainers, and compressing to install the the cotter halves.
Getting closer to putting it all back together!