While I’m new to Hondas, I’ve been doing valve clearance measurements/adjustments on my DOHC shim-over-bucket Triumphs for years.

On my client's CBR600RR, I have the head cover removed, all holes plugged with rags, and am ready to pull the exhaust cam, as only exhaust valves need adjusting. I don't have a cam chain tension holder tool and was wondering since I am removing only one cam, if I can safely do so without having to use the tool.
I read a how-to here where a screwdriver was inserted instead of the tool but, after looking at the tensioner on my bike, found there was no way to get much of anything in there due to only 1 1/2" inches of room between the opening on the tensioner and the bike's frame. Later, I re-read the how-to and found it was for a Hurricane and not a CBR600RR.
I certainly do not want to wind up with the cam timing off, but really don't want to buy a specialty tool that I'll likely use only once. Plus, my client would like their bike back sooner than later.

Secondary question:
Weirdly, all eight exhaust valve clearances measured at .14mm, where spec is .28mm +-.03. I did three separate measurements of all valves, with three or four full engine rotations in between, and got the same numbers each time. I just find it odd how their clearances are all the same, and at half the specified clearance . Anyone ever heard of such a thing?

Thanks!
-Sparky

 

Sounds like a evenly worn motor to me nothing wrong with that.