skookum
Excellent, impressive.
Big, strong, durable, reliable, trustworthy, doughty.
The electrics were fine (amazing considering Joseph Lucas, the Prince of Darkness made 'em), although they were positive ground - admittedly not a serious problem unless you wanted to add electrical accessories - and mostly we didn't in those days unless you had a Hardly Dangerous "garbage wagon". (This was probably cuz the Harley was the only bike with a skookum enough electrical system for the load.)
Where it comes from
First attested in 1825–35. Borrowed from Chinook Jargon, from Lower Chehalis.
Adapted from the Wiktionary entry skookum (CC BY-SA 4.0).