Vapor lock??????My 225 HPDI had that problem when hot it would not start unless you got in the hot foot pretty good but the funny thing is you could back the motor in the shade and it would fire up with no problem at all.Dealer checked with Yamaha and they said tilt motor slightly and use NON ETHANOL FUEL.Trying to run the ethanol fuel out and use the non.Will let you know how it works.