I know someone who has a 115 4s Yammy and he says he almost ruined this motor because he idles about 50% of the time. He fishes some rocky flats in N Fla gulf.
I thought the 4 strokes were tailor made for idling??
If he almost ruined his engine it wasn't because he was idling 50% of the time. There must be other factors, including the possibility that some wrench, or wannabe wrench, had to sound knowledgable and didn't have anything sensible to say.
I got more info. The motor was not getting hot enuff. The pistons weren't expanding enuff, and allowing gas into the crankcase.
"Making oil". He was running less than a 1000 rpms a lot!
there is a tech bulliten out for some of the F115 motors. sometime in 01 or 02 I believe.
engine temp is critical, its mandatory to periodically check the T-stat.
after extended idle times you really need to spend at least 30 min above 4000 RPM and the engine MUST be capeable of 5800 or so at any given load.
unlike carburated engines fuel is injected reguardless of if it can be burned.
excessive combustion pressures due to engine lugging will cause blowby fuel to pass the rings.
periodic leakdown tests are needed as occasionally the ring gaps will line up. I have seen it twice. when they line up the main symptom is making oil.
other than that my F150 can spend hours idling
Yamaha 4 strokes not to idle?
Linear Mode
