Stupid question, but what is the purpose of the sight glass on the left side of the engine? I know the one on the right side is to check the oil. I could find any info on it in the useless manual. Anyone know?
Well, I find the TDC marks real helpful when I check or adjust the valves. ;D
The timing marks are pretty much for just checking it. One mark is either for static timing or no advance at idle (can't remember) and one is at full advance. If the flywheel key ever sheers or the timing gets out of whack for some other reason it will show up cheking it with a timing light. I think some adjustment is possible by moving the timing pickups, but it ain't a casual job.