It's Comic Sans. Best typeface ever.
Serious answer; it's drawn from scratch just like all other Yamaha and Kawasaki model logos. Very few manufacturers use box-stock typefaces. If they do then they modify some part of them to make them custom.
You'll either need to reproduce it or find someone who has already reproduced it. Unfortunately there won't be a downloadable font file that you can type the word 'SuperJet' and crank out a 1:1 logo.
Edit: Below is a somewhat clean version from the 2007 (same logo as the 2004) that your graphics shop should be able to reproduce in 30 minutes or less. Right-click and save it to get the full size version.