04 f-150 losing RPM and speed at full throttle

[danielreilly09]

I just got off the phone with the mechanic. The balancer is going to need to be replaced. It had always made kind of a whining noise but I thought it was just the motor and how it should sound. They also just talked to Yamaha and apparently they initially only replaced one of the fuel injectors. They are now going to replace the remaining injectors as well. Do you think this could be the fix? I am hopeful because when I was on my trip and they cleaned out the injectors, it ran normal for two days before starting with the problems again

[99yam40]

If cleaning injectors helped before and they did not clean the whole fuel system at that time, then they probably just plugged up again. It would be a good idea to clean it all up along with the injectors again.

Not sure replacement would be needed unless the tests before and after cleaning shows the need.

This info should have been given at the first of this thread, it would have helped

[rodbolt17]

myself?
I would have the injectors sent to flagship marine,just like the yamaha tech bulliten suggests, and have them cleaned and tested.
much cheaper than buying new.
while they are in transit clean the VST and all fuel lines,again.
thats the issue with older low hour motors.
fuel systems get buggy.
but personally, I would be embarrassed to call yamaha over a simple injector problem.