Hunt, IRC 2WD Cup champion in 2010, was 100 metres into the Vleteren-Krombeke test when his car lost power and stopped. At the time, he was holding a provisional third place in the two-wheel drive standings.
The 23-year-old now shares the title lead with Honda Civic Type R driver Martin Kangur heading to round seven, Rally San Marino.
“It was a real pity as we were in a very good position in Ypres and we still had some speed left in reserve,” said Hunt. “We’d experienced some electrical problems earlier and changed a lot of parts in service, but that still didn't solve the issue. We’re obviously disappointed but we have enough events left on our programme to try and get the deficit back.”