Which oil for my Firestorm?

What oil would you suggest I should use in my Honda Firestorm? Fully synthetic or semi-synthetic? The bike is a 1999 model with 14,000 miles on the clock.
Martin Thomas, Salisbury
On a 14,000 mile machine, fully synthetic is good but then it’s also expensive. Semi-synthetic is perfectly adequate and cheaper. We’re told that Honda UK puts semi-synthetic in all of its company bikes..