Sean O'Rourke posted:

Orizaba (18,491') is the highest peak in Mexico and 3rd highest in North America.  We're not aware of a lot of FKT activity on Orizaba, but Sean O'Rourke pointed out this interesting tidbit:

http://www.alpineexpeditions.net/about-us.html

Mt St Helens (8365') is unusual in that it is basically a "new" mountain since the 1980 eruption which removed 1312' feet from its height.  summitpost.org lists 3 main routes, Butte Camp, Worm Flows / Swift Glacier, and Monitor Ridge (shown on the map below).  The latter 2

Frank Lenihan posted the route:

Yushan, at 3,952m (12,965ft), is Taiwan's tallest mountain. I climbed it twice using the classic two-day route, ascending from the west, climbing from the trailhead to Paiyun Lodge on day 1, and from Paiyun Lodge to the summit and back to the trailhead on day 2. For single-day ascents, most climbers spend 10-12 hours going up and down the mountain. 

Tacaná is a 4060m volcano on the border between Mexico and Guatemala. Santiago Carsolio reports that there was a previous FKT by "a German guy" of 3h15m for the ascent, 5h00m-5h30m RT. He also said, "This challenge consist of running from the town of Chiquihuite (2050m) in the Mexican side, going to the main summit (4095m) and down in just 15 kilometers, this makes it a double Km vertical challenge and then down. Tacana is the second highest mountain of Central America.