Power surges and reductions, 50 hp EFI

[Rod Goodman]

My 10 yr old 50 efi owned for a year has had problems since a full service, firstly losing power at full throttle and then experiencing surges. Normal full throttle achieved only 4000 revs but on surges leaped to 5200.. Diagnosed with contaminated fuel I have had the tank flushed, new lines a new fuel pressure sensor, new plugs and new fuel. Following this work a test run of about 1 and 1/2 hours had smooth running at 4000 revs and below , but heading back to the marina had sudden surges up to 5300. Any ideas?

 

[Faztbullet]

Sounds like injectors need cleaned...

 

[Rod Goodman]

Thanks for the suggestion , cleaned and now running great.

 

[Texasmark]

Thanks for the suggestion , cleaned and now running great.

Might grab some Sea Foam and keep it in your fuel. I found about it on this site about 10 years ago. Has yet to fail me.