2004 f150 yamaha rough idle

[boatinbob]

i have a 150 4 stroke, starts good, rough idle when in gear, some hesitation on hole shot. used 1 bottle of heet for possible moisture in gas, no fix. should i try fuel injecter cleaner next ? plugs look good

[boats.net]

Try a new set of spark plugs, may need to idle control valve checked to see if working properly.

[boatinbob]

2004 f150 rough idle

installed new plugs, and ethenal free high octane gas , also tried fuel injector cleaner . no change in performance, talked to two local yamaha dealers , said to try yamalube ring free fuel additive , runs worse now , seems like it is starving for fuel , slugish take off , slow top end. cleaned moisture separator bowl and filter , not dirty.what about vst filter? where is it located? running out of summer , like to get problem fixed soon any advice greatly appreciated

[Konaboy808]

did you try changing out your fuel water seperator and check your gas line,had the same problem and found that my water seperator was clogged i mean the whole water seperator assym. was clogged and gas lines caused it.

[200090tlry]

I bet it is fuel related

Check quick connect does it have oring. Does fuel drip anywhere?

[boatinbob]

f150

what quick connects do you mean ,no drips anywhere. think i will try portable fuel tank, lots of talk of ethenal gas eating inside of gas line , starving engine for fuel at acceleration and full throttle. thanks for response

[jb123]

if you think you have an issue with ethanol separation, do yourself a big favor and drain tank and start fresh, then clean the rest of your system

[TownsendsFJR1300]

F150

My F150 had the fuel line between the exterior fuel filter and the engine fuel filter literally have the inside come apart (was installed new when I re-powered the boat in 2007) from the ethonol fuel. The line was replaced. I was using a product called "Gas Shok" which seemed to help with the ethonol fuel but didn't fully address any water in the system. I did find what appeared to be water droplets when I drained the fuel filters or FI pump housing.

I found a product that actually works in keeping the water in the tank in suspension, its called K100. The boat is an 1997 Angler 204 with the original gas tank. Since using the product, (and began using ethonol free fuel) the droplets are gone (actually in suspension getting burned out).... The engine runs better now than new.

It should also be noted that the ethonol swelled the plastic engine fuel filter and wouldn't allow it to fully seat causing air to get into the system. It had expanded approx .030" from the ethonol and would not go into the plastic engine mount. A slight amount of fuel would also leak if you pumped up the primer valve hard from the fuel filter.

Check the o-ring and make sure the plastic lower housing is seated and NOT LEAKING.