I also have learned the hard way with regards to these mac 38's I had the self same issues with a powercraft chainsaw which is a carbon copy of the mac 38 chainsaw except they were blue in colour (see photo) I found I could only start mine with a 240v ac domestic drill with a modified starter rubber. bit of a bummer unless the local flying field has a mains supply right next to take off[&o][&o] and here is a piccy of the converted engine its dimensions are excellent but this getting to spin in excess of 1400 rpm is a bit of a bummer....well it is for us in blighty never mind I'll keep looking for engines to mod