Full Power

[ejmouhot]

2004 Yamaha Outboard 90HP
Took boat out 2 weeks ago, engine started right up but sounded like one cylinder not firing, cleared it self up in about 20 seconds did not have a problem the rest of the day.

Took it out last week did the same thing but did not clear up. would not get on plane. Starts up with no problem just not getting full power.

Thanks for your help.

[99yam40]

check:
compression
spark
timing
Plugs and wires

if all is well with those then:
fuel pressure/vacuum
fuel pump for hole in diaphragm
clean carbs and adjust as manual calls for