Of the very many British bikes I've owned the MK2 Squariel was, and still is, one of my favourites...
I did a lot of miles on mine and have to say one big plus was the gentle power delivery at slow speeds...One of the best bikes I have ever ridden in the snow and ice for that reason...
Don't believe all the stories about over heating...The Mk 2 ran hot but it didn't really cause any problems. I fitted a Trident oil cooler to mine and that improved things somewhat at low engine revs.. (I had already fitted an oil pressure gauge before I fitted the cooler)...
Water ingress into the distributor could also be an issue in bad weather so a distributor cover was 'de rigeur' if the bike was used in all weathers...Coupling gears tended to be noisiest on the 'over run' and tended to whine a bit under load at high speed but you soon get used to it...
'10 to a 100 in top gear' wasn't a rash claim made by Ariel in their advertising...The motor has a brilliant useable power range...Ian