Hi Darryl, I used "Paint Shop Pro 8" there is an option to add text to a photo, I used the paint brush tool to draw the lines.
Most photo editing programs have these options.

Grumpy, I don't think the valves in the fuel caps on the older chainsaws were very reliable (they always seem to dribble a little fuel). A separate fuel vent line with no valves is a better system.

Here's a photo of my "Stihl 07", the tank vent is a 2" length of tube
with a grub screw in the end, simple but effective.
[Linked Image from i4.photobucket.com]