TOKYO—Toyota Motor and Honda Motor were upbeat about their full-year profit prospects on Wednesday as tight vehicle supplies caused by a chip shortage allowed Japan’s two biggest automakers to charge their customers more. The Japanese carmakers are also benefiting from a weaker yen that raised the yen value of their overseas earnings. Toyota and Honda like other car makers are cutting output because they cannot find enough semiconductors amid COVID-related supply chain disruptions and competition for the key component from other industries, such as electronics. Lower production, however, means their customers are more willing to buy cars with fewer financial incentives that carmakers typically offer to lure them. “We are seeing a further 10 percent reduction in incentives in North America during the second half of the business year after they halved to $1,000 earlier,” said Kohei Takeuchi, Honda’s senior managing executive officer told a news briefing. Toyota stuck with …