Hard starting when warm

[Soundslikefun]

My 1964 merc 650 starts instantly the first time each day and last year ran great. This year, after running a while, it will not start when warm. Never fails to fire up when cold. Where should I begin? This has happened 3 of 3 times this year.

 

[Soundslikefun]

Re: Hard starting when warm

Ok, thanks!