jayhendo77
New member
Hi everyone, I run a boat rental and tour guide company down here in the Florida keys and mechanic work is hard to come by here. I've become fairly good working on these motors VSTs, stators, starters, fuel injectors, fuel rails, but I am stumped on the 06 yammy I'm working on right now. I need to get back out on the water asap for our customers. first symptoms: easy start, rough idle with a small shake, needs harmonic balancer which will be getting done this week. boat will not plane out at full throttle (no we don't have a tach on the boat yet, but one is coming). Seems like its not firing on all cylinders, but i pulled each wire during idle and each cylinder had rpm drop audibly. I shot a can of powertune through it and replaced the plugs and the only change was a smoother idle. So i cleaned the vst replaced the vst filter and test ran it with no change but back to a rougher idle. I'm stuck at this point. I definitely think its a fuel issue. If anyone can point me in a better direction until we find another mechanic it would be greatly appreciated. 248 hours on the motor and was professionally serviced one month ago. Coil packs replaced last week and 4 new fuel injectors 2 weeks ago. I did notice some residue at the bottom of the fuel filter which i cleaned out. Spark plugs were all white tips with black residue on the threads. top plug was clean.
