See the scorecard from the game here
The Napier Tech veteran, who has played for the club since 1990, completely shattered the club's highest individual score of 249.
With a previous highest score of 213 not out, Findlay was hearing calls from the sideline to push on to 400 or even 500 in the 45 over per side match.
"My hammies started to tighten up, I hadn't really run much but I ended up retiring in the 33rd over."
St Johns used 10 bowlers in a vain attempt to stop the parade of fours and sixes with no bowler going for less than eight runs per over.
Napier Tech went on to score 578 from 45 overs at a run rate of 12.84 before St Johns were skittled for 177 in reply, losing by a mammoth 401 runs.
Findlay, a former Central Districts Stags and Hawke's Bay representative, said he stopped playing premier club cricket a couple of years ago and doesn't attend trainings any more, preferring to play just a few games a season.
He said the St Johns bowling probably wasn't up to senior grade standard and said the boys from the Hastings college will probably struggle in the association's senior men's club competition.