If it's blue, then his saw is a Zip. Same basic saw as an EZ-6. Different starter. Single reed. 4.7ci instead of 5ci. Made a few years later than the EZ-6 (which had been replaced by the 600D). Homelite Zips are easy to find if you want one...
I know a fellow who has at least two Zips and they're both for sale...