Alternately you can get an ungraduated set of internal measuring sticks that you remove and measure with vernier calipers/external micrometer.

Actually called a telescoping bore guage.
Heres one
http://www.ebay.com.au/itm/6PCE-5-1...ar_Parts_Accessories&hash=item3f0e131e95


Its what i bought. Not overly accurate but you can get an idea from it.
As was mentioned above, fresh rings in a worn bore will give service. I got the above measuring sticks and they were useful for a rough check of diamter, run out and tapering on the bore in my bike motor. Ring a ding ding. Yeah it was a little bit worn and ridden hard and put away wet.

It smoked, its mant too its a two stroke.



I think with all those mowers your going to have there Jeffery you will need to host a monthy mower start up day. Imagine that, a backyard with 20 plus Victas ring dinging away. Music to my ears. Beer is your shout.


Heres a cheap version of the real deal if your feeling rich.
http://www.ebay.com.au/itm/CYLINDER...ar_Parts_Accessories&hash=item45fd169b4e

And a set in the US that are not cheaper but look to be a bit better quality
http://www.ebay.com.au/itm/dial-bor...ck_Parts_Accessories&hash=item45fd0e1e28

Sometimes you can get good stuff like this for a good price slightly used from an army surplus disposals store.