Japan's core machinery orders rose for a second straight month in August, handily beating market expectations, signaling a pickup in capital expenditure that should encourage Prime Minister Shinzo Abe ahead of a general election this month.

The premier hopes to convince voters in the Oct. 22 elections that his "Abenomics" recipe of aggressive monetary stimulus, fiscal spending and reform plans has improved the economy enough to stoke a sustainable recovery.

Cabinet Office data showed on Wednesday that core orders, a highly volatile data series regarded as an indicator of capital spending in the coming six to nine months, rose 3.4 percent in August from July.