By the time the New Zealand Grand Prix rolled around again the Velocette was going very well indeed. Burt and Duncan decided to make an all out assault on the Rangiora Handicap. Duncan insisted Burt buy a new race spark plug for the occasion and although Burt grumbled he finally gave way and did so. The race started splendidly with Burt well to the fore and he was able to run in the top three or four places, lap after lap. As the end of the race approached it looked like Burt would manage a podium finish at the very least. But all such hopes were dashed when the Velocette suddenly gave up and coasted to a halt.
Once the dead bike had been retrieved Duncan set about performing his usual post mortem back at the pits. The first thing he found was that an old spark plug had been fitted. Seething with silent rage he replaced it with the new one and the bike ran faultlessly. He switched the machine off and turned to Burt, who suddenly remembered he had urgent business elsewhere. He had not gone five paces before he found Duncan barring the way, eyes flashing with genuine anger.
All over the pits, riders, mechanics, wives, girlfriends and assorted rubberneckers stopped to hear Duncan Meikle tell Burt Munro exactly what he thought of his stupid, idiotic, thick-headed, time- wasting, plain bloody perverse, mean as sin attitude, and to learn just what Burt Munro could, in Duncan's opinion, do with it. This seemed to involve inserting a motorcycle inside himself, after first wrapping it in barbed wire and dunking it in battery acid.
Having made his point Duncan stormed off, leaving Burt to find his own way home. His old friend had once again stopped playing speaks. This went on for some months, by which time Burt was ready to catch a ship back to America. The day before he was due to leave, Duncan turned up and had a cup of tea and a gingernut as if nothing had happened. He wished Burt a good trip and quietly left. Burt was much relieved. It was bad enough when Duncan went off his head, but it was worse when he just went off.
One Good Run Tim Hanna p 198-9