F150 Fuel Injection Prob.

[exttrimmer]

Hi Guys

I have a pair of 150 four strokes. I recently purchased some bad fuel at a local marina I dont usually use.
The bad fuel made 1 engine idle rough, surge in rpm while at idle. Same engine would not maintain rpms at wot. Sounded like engine was starving for fuel and sucking air. I took boat in to have issue looked at. Also had engine and gear oil changed in both engines.I was billed for replacement of all filters as well
On problem engine issue ended up being fuel injectors were clogged. I had asked them to clean both engines injectors but tech said that 2nd engine was fine.
It is now 10 days after getting boat back and after running approx 20 hrs on engines, the engine that was fine is now having same issues as 1st engine.
rpm's surge at idle, wont maintain rpms at speed. Engine that was original problem is running fine, after having injectors cleaned.

I dont have shopmanual yet(purchasing online on Monday).
Do I need to get VST cleaned, Can average DIY'r accomplish this repair. Do I need to take fuel injectors out to have cleaned professionally.
Anyhelp would be greatly appreciated

Thanks

[99yam40]

I would wait for the manual, hopefully you ordered the Yamaha service manual, but some like the aftermarket ones. Best to have both maybe.

I also think it is best to send injectors off and have them tested and cleaned.
They will send a report showing before and after

If you did pump bad gas and you keep running that gas it will continue causing problems

[Tucker]

There's a pretty good thread here complete with pics of a guy that cleaned the VST and injectors on a 150. The VST appeared to be a major PIA to remove because he had to remove the intake.