Df 50 has low power at startup

[patpat]

2008 df 50 with 150 hrs. Runs great with good power once it warms up about five minutes. For first few minutes the motor acts as if it is overranging. Revs and slows with low power. Will not exceed approx 4k rpm. Once it warms up completely it runs great for rest of day with one exception. If i use ethanol fuel it will start great (after first startup) runs at correct rpm for about a minute, then dies as if starved for fuel. Fuel bulb will be soft. I pump it up and it runs great again. No more problems unless it is shut down for an hour or so. Same problem repeats when i start again. If i pump bulb, no problem. I usually use ethanol free fuel 89 octane, and add ring free. Thank you

[patpat]

I posted this thread 13 months ago. Never any reply. Changing plugs cured low power at startup problem. Stalling problem disappeared for a while for no known reason but is back again. Starts and runs great. After sitting for awhile and starting up engine runs about 100 yds and dies. Pump bulb and it runs great. Is this the vapor lock problem I've seen in other posts? Any help would be appreciated.

[boats.net]

Vapor locking can cause this issue. Fuel pump can also cause the same problem.