Honda's F1 engine chief Yusuke Hasegawa has admitted the mechanical problems that hit McLaren-Honda on the second day of the first pre-season test are a "worry" for the opening race in Melbourne in just a few weeks time.
McLaren were forced to cut short their test day on both Monday and Tuesday following pow.er unit problems. Although Monday's issue was a straight-forward fix to the shape of the oil tank, Honda have yet to understand why their second power unit failed completely on Tuesday.
That unit was immediately flown back to Honda's facility in Sakura, Japan, where it is undergoing a detailed investigation to understand the cause.
But with Honda due to bring an upgraded unit to the second test – also the unit it hopes to race with in Melbourne – Hasegawa has admitted concerns and says it could compromise their start to the season if they can't discover the cause of the fault and correct it in time.
"The first day we had an oil system issue, the oil tank. Normally the oil tank has to manage the oil level but this year we had some bad oil management so that is why we need to modify the oil tank system," he told Spanish TV station Movistar.
"The second day we had a mechanical issue and still we don't know the root cause of the problem. This is more fundamental and more serious I think. We need to find out what was causing the issue."
When asked if it could impact the first race of the season, he replied: "The oil tank definitely not. [The] mechanical issue, I don't know. We're yet to be confident about that, but of course I worry about that."
It's one of just a handful of concerns for McLaren with speculation that Honda is unable to run its new power unit at full power due to reliability fears, with suggestions it is less powerful than their 2016-unit in its current state.
