I'm checking valve clearances on my '94 750F. The Honda manual refers to a timing "mark" but each 'T' mark has two scribe lines, one of which is longer for the #1 'T' mark. With this longer mark aligned with the index notch, the cam wheel marks correctly align with the cylinder head so it seems intuitive that the similarly-positioned 'T' mark for #2, #3 and #4 are the correct timing marks to refer to. The cam position difference seems insignificant at any point between the two 'T' marks so my question is, are these parameters within which the clearance may be checked or is one of the marks there for another purpose - (i.e., to confuse people), or maybe for race tuning? It's probably not important but out of curiosity, what is the purpose of the other two marks between the 'T' marks? Thanks in advance.
You would use the scribed T mark...the scribed line marked F is the ignition timing mark...and the two scribed lines that aren't marked are ignition timing full advance.
marks are not very important for checking valves as long as the cam lobe is generally pointing away from the bucket.....