My "best" HT23 has had a problem recently where the ignition switch was messing up mechanically, to the point that it would bend the key to get it to the start position. I guess it was not a big surprise, given that it appeared to be the original Indak switch from 1979.
Did a little research, and waded through the catalogs at my very local, and friendly, OPE dealer, and found that Oregon has the switch as part number 33-393, which is also the JD number AM103286. Both Stens and Rotary have equivalent switches, all for considerably less than $20. And my OPE guy had one in stock, so all in all a good day, and no more bent keys!