VST Tank Issues caused by heat from Engine?

[rodbolt]

Re: VST Tank Issues caused by heat from Engine?

you still simply dont get it.
the feed pump,due to a 10 PSI check valve, feeds fuel to the VST at 10 PSI minimum.
more than enough to balance out anything.
most likly the fuel lines are contaminated.
see that quite a bit.
I maintain over 50 of these F225/F200 and own an F150.
all get E fuels none have problems.
however when it happens I replace ALL the fuel lines.
let a section of your line dry overnight then inspect it with a flash light.
any white or yellowish deposits mean the line is contaminated and a repeat failure is assured.
the VST vent is a check valve as well.
keeps the system mostly nuetral and aids in vapor control.
will allow air in and out but try to nlow through it.
its that shiney metal thing that goes into the air box on the upper port side.
your deer dog is hunting rabbits not deer.

 

[rib4charter]

Re: VST Tank Issues caused by heat from Engine?

Unfortunately it is not been my dog chasing rabbits it has been my checkbook chasing ghosts in the engine. I have replaced the following on my boat after the tank was pumped out the first time when I thought it was just bad fuel.

1. Pump inside vst tank
2. VST Tank itself
3. VST Filters
3. All fuel lines going from tank to water separator and from water separator to the gas filter inside engine. Then from the gas filter up to the vst tank.
4. Gas filters on engine
5. 4 water separator filters
6. Fuel bulb

I cut open the yamaha fuel lines the other day to check how it looked and it looked clean. same thing with a section from my black fuel hose going from the tank.

As I stated before, if someone can explain to me how the sodium sulfate particles that are large enough to feel rolling between your fingers are getting from my gas tank past 2 filters one of which is 2 micron I would like to hear it. The only part of my fuel system that was showing any sort or issues was the vst tank.

We can debate the issue of a vaccum being created in the vst tank, but there is no question the vst tank gets hot. I have felt my tank after running the boat hard and it gets hot to the touch which is an issue. My view still remains, my engine puts out enough heat to cause the ethanol to boil in the vst tank and that is what is releasing the deposits because nothing else shows up in the rest of my fuel system.

I am done running ethanol as I have spent way to much money chasing ghosts and missing boating time so I am 100% gasoline from now on.

 

[GoogieMan]

Re: VST Tank Issues caused by heat from Engine?

I am done running ethanol as I have spent way to much money chasing ghosts and missing boating time so I am 100% gasoline from now on.

i dont understand why anyone would use a second rate fuel in there outboard anyways

 

[rodbolt]

Re: VST Tank Issues caused by heat from Engine?

in my area your pretty much stuck with E fuels.
some stations claim to have E free fuels but every time I test a sample I get 5% to 10 %.
you CANNOT clean nor polish that gas tank by simply pumping it.
Ethanol s a very good and very corrosive organic solvent.
thats why its trucked and not piped.
once the crud,oookiees or what ever you wish to call it is in the tank or lines the ethanol will continue dissolving it and feeding it to the VST and engine systems.
try dissolving 3 tbl spoons of sugar in a qt of water,pour this solution through a coffee filter,tell me how much sugar got trapped.
its the same with ethanol,once it dissolves something it becomes part of the solution and is very hard to filter yet maintain the fuel flow needed to run.
once this solution starts saturating in the VST it can fall out of solution,ever make rock candy?
if the problem is severe try drainig the VST after every tank of fuel.
only way to check for fuel line contamination is allow it to dry thoroughly then inspect it.
this E scam has been a bummer for everyone.

 

[GoogieMan]

Re: VST Tank Issues caused by heat from Engine?

in my area your pretty much stuck with E fuels.
some stations claim to have E free fuels but every time I test a sample I get 5% to 10 %.

Then i feel sorry for ya! at least here we have a choice

 

[rib4charter]

Re: VST Tank Issues caused by heat from Engine?

Just a final update on this project. I have had no problems with the engine since flushing the tanks out, adding the heat shielding, and going to 100% gasoline. I am not suprised by the result and from talking with other who have emailed me if you run the F225 with ethanol and you are getting repeated problems with the vst filter, follow what I did and switch to 100% gasoline. If you can't get 100% gasoline, try the heat shielding on the vst tank and the fuel lines at a minimum and clean out the fuel cooler on the engine so it is operating effeciently and it may help keep the fuel from boiling over releasing the deposits of sodium sulfate and other debris trapped in the ethanol fuel.