Specifically on a VF500F engine. The service manual says to "ream" the valve guide before measuring. They have a Honda part number for the reamer but don't specify the size or type (there are many). They say that this step is to remove any carbon that may foul up the measurement. I have good Starrett micrometers already for measuring the valve stems. I was going to purchase these inexpensive telescoping bore gauges: https://www.amazon.com/gp/product/B07CSNYM13/ref=ox_sc_act_title_1?smid=A2ERI74FFBS1IL&psc=1 to measure the ID of the valve guide. Can I just clean out the carbon with a brush and some solvent, or am I wasting my time trying this without first reaming the guides? Thanks for any guidance you can provide.
I def wouldn't be reaming my guides just to check for possible wear unless I absolutely knew I had the brand new correct tool. And even then I would be cleaning with solvent and pipe brushes first before even considering any reaming operation.
guides are very unlikely to have excessive wear except on very high mileage bikes, and few VF500's last that long. u can test clearance by installing valve and have it sticking out a little from seating then pushing the head from side to side and seeing if it moves noticeably.
