Yamaha 115 HP 2005 4 stroke

by Bryant B
(Pensacola, FL)

Starts great, idles great, runs at low throttle setting great, when advance the throttle it will sputter a bit but get up to roughly 2/3-3/4 throttle and run ok, at full throttle it sputters and only gets to full power in short spurts.I changed the spark plugs (installed new ones), first run right after changing plugs worked great idle speed to and through full throttle. Yeah, thought the problem was fixed. Next run about 30-40 minutes later nope same issue. Next day changed the fuel/water separator filter. Drained gas in old filter into a clear container no signs of water but it was an old filter and there was a fair amount of fine rush particles. First run that morning was great idle to and through full throttle. Yeah thought the problem was corrected, came back to the dock picked up my daughter and sure enough same issue. I have take off the new fuel/water filter twice and emptied the residual gas from the filter into a clear container each time (each time in a new clear container) - 3 containers in all, 1st time for the old filter residual fuel which was fairly dirty with fine particles, the 2 times I removed the new filter and emptied after running the motor the fuel was clean but did have some very minor fine particulate. Any thoughts or suggestions would be appreciated!! Could it be the igniters or fuel pump? Again the problem is getting up to speed when throttle is roughly 3/4 to full advanced and once at cruise speed with throttle at 2/3 - 3/4 advanced it is ok but seems like it is on the edge of sputtering (but not sputtering or stalling at roughly 2/3 throttle) once you advance past roughly 3/4 to full it will sputter intermittently and never maintaining full speed at full throttle. Thanks Much!

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