fuel filter/water seperator question

fastal

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I need to fire up the motors in the next few days prior to my seasonal launch. My question is should I put the new filters on prior to doing this or fire up using last years and then change over to the new once everything checks out. Suggestions and tips much appreciated....thanks
 

seasick

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I fire up first and warm up the motor, check out everything, fluids, leaks ( hopefully none) etc.
After the motor cools, I change filters, plugs, and whatever else is on my list.
I always fog my motor before layout. As a result when it starts in the spring it generates a lot of smoke. No need to contaminate new plugs.
If the gas went to junk over the winter, the old filters will get all the crap and not new ones which would then need to replaced. I also drain the fuel out of the old filter into a jar and let it sit just to see if anything settles out.
 

Heavy Duty

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You might want to open the drain screw at the bottom of the VST tank and check the gas there first before you light her off. I serviced mine this past weekend and drained some of the VST tank fuel in to a clear bottle to look at it. The gas looked fine but smelled like varnish. So I drained the gas completely out of both tanks. I pulled the primary fuel filters and go A LOT of water out of them. So I change them as well. After doing a serious prime, had to refill the VST tanks, both engines fired up without any problems. I think from here on out when I lay mine up for the winter I’m going to drain the VST tank.
 

seasick

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Heavy Duty said:
You might want to open the drain screw at the bottom of the VST tank and check the gas there first before you light her off. I serviced mine this past weekend and drained some of the VST tank fuel in to a clear bottle to look at it. The gas looked fine but smelled like varnish. So I drained the gas completely out of both tanks. I pulled the primary fuel filters and go A LOT of water out of them. So I change them as well. After doing a serious prime, had to refill the VST tanks, both engines fired up without any problems. I think from here on out when I lay mine up for the winter I’m going to drain the VST tank.
I wouldn't for several reasons. If there is water vapor, things could corrode. At least the ethanol acts like dry gas. Secondly, gunk on the tank walls and internal parts which may be disolved now coud solidify and plug things up.
I would make sure that you have stabilizer in the VST fuel
 

Heavy Duty

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seasick said:
Heavy Duty said:
You might want to open the drain screw at the bottom of the VST tank and check the gas there first before you light her off. I serviced mine this past weekend and drained some of the VST tank fuel in to a clear bottle to look at it. The gas looked fine but smelled like varnish. So I drained the gas completely out of both tanks. I pulled the primary fuel filters and go A LOT of water out of them. So I change them as well. After doing a serious prime, had to refill the VST tanks, both engines fired up without any problems. I think from here on out when I lay mine up for the winter I’m going to drain the VST tank.
I wouldn't for several reasons. If there is water vapor, things could corrode. At least the ethanol acts like dry gas. Secondly, gunk on the tank walls and internal parts which may be disolved now coud solidify and plug things up.
I would make sure that you have stabilizer in the VST fuel


Actually, one of the master mechs were I have my engines serviced when I have the boat at Manteo, stated that 90% of the VST problems could be solved by draining the VST when you are going to lay the boat up for a period of time fuel stabilizer or no. Apparently the E-10 gas has a very short storage span before it starts to go stale. The present day fuel stabilizers are good but not worth taking the chances on after a long winter layup. He is also the one who told me to sample the fuel from the VST before you start the engines the first time to make sure you do not have water, dirt, and old gas in the VST. The gas in the VST tends to go bad much faster than the gas in the fuel tank. I guess that is because there is less of it. The guy does have a very good reputation. So just doing what he suggested and so far have not had any issues with the engines. I know that day is coming though.
I did get ½ of a 12 ounce bottle of water, and other crap, from the primary filters that were put on new last fall just before layup. So I changed them before I started the engines.


HD
 

Doc Stressor

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Re: fuel filter/water separator question

I agree with HD. Drain the VST before storage. The last thing you need is for stale, moisture laden (possible separated) fuel to get into your injectors. Fuel grade ethanol also contains trace amounts of sulfur compounds that form sulfate (sulfuric acid) in the presence of moisture. That can corrode the aluminum body of the VST and form the white powder that you see the techs cleaning out of the high pressure fuel system filters. You don't want that stuff forming downstream of your 2 primary fuel filters.

I drain the VST on all of my motors whenever they aren't going to be used for more than 2 months.

And it is a good idea to drain the fuel out of VST and to replace the fuel filter before firing up the engine after prolonged storage. It only takes one "event" to cause a major fuel system problem that can cost over a grand to repair.
 

seasick

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I don't buy those arguments. First of all, the VST is effectively sealed unlike the fuel tank. Therefore the fule would 'age' slower.
Secondly oxygen is needed for corrosion to take place and a full VST has a lot less air than an empty one. It is also impossible to remove all fuel vapors from the VST even if drained. By adding more air, you have added more moisture (depends of course on your relative humidity)
If you get phase separation in the VST you can be pretty certain that you have it in the main tank so draining the VST won't help.
I do not drain my VST and the boat sits for months at a time during the off season. 10 years on the motor and never a problem. I only add stabilizer in the winter. A lot has to do with the design of the fuel filler /vent. It does not allow water to easilly get in and it effectively 'seals' the tank from outside air.

I believe you when you say you drain and don't have issues. I am just saying that I suspect a much larger percentage of Yami owners don't drain and don't have issues either. It's kind of like cleaning that O2 sensor. Some do it every year, some never do it.
 

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I have heard both arguments re the draining/ not draining of vst tank for the winter. I had heard NOT to drain because some type of pump seal could dry out. I had heard drain it because of the reasons stated above (and Yamaha specifically recommends it). I did NOT drain mine this year before layup, but drained and refilled in the spring before launch and I did not see any contaminent's in the fuel that I drained. One thing that I had read is that you better make sure that VST is primed before you try to start it (if you drained it in the fall). Failing to do so supposedly can cause a problem by running the pump in a dry condition. I dont really know the answer as I am only going by what I have read on the subject. As of now, I'm not really sure what I will do next year but leaning toward NOT draining. I kind of equate it (right or wrong) with my gas tank. I have always kept it 90% full/ stabilized and never had a problem.
PS...engine runs great since launch
 

BobP

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The white powder material has been identified by Yamaha as sodium sulfate some time ago.

I get it on my 2 micron VST filters and the VST float and walls of VST tank, but so far no trace of it in my 2 micron racors. Meaning it occurs downstream of the racors and not from gas supply.
If aluminum was involved, what are gas tanks made of ?

I clean the VSTs and reuse them. It's a two part device that snaps together via O ring seal. This is a easy DIYer job, even on the boat on the water. Original VST filters did not snap apart, apparently changed due to offering a cleaning solution. The fileters are not cheap (i.e. relative to monster racors)so it makes sense.

Yamaha recommends to keep VST tank empty off season. I leave it empty after changing VST filter season end. Before restarting in spring, hand bulb pump it full until float shuts off fuel.

I think high heat is involved since the VST sits under cowl and motor sitting in sun all the time with no air flow, boat gas tank compartment not the same - very cool. Little time relatively speaking with motor running so doubt it from motor generated heat and also cowl is ventilated when motor is on and boat is moving. Others suggested it is high heat and vacuum, still others say powder is from perhaps stray current as tank is reported as being ungrounded.

Insides of my tanls are pristine, no corrosion at all 5 seasons gone. The white powder leaves a trace that once wiped cleaned appears as a bit more shine on surface.

Stabil and the other preservers are for intended purpose.

The VST is easy to drain so can do so before using motor, but be sure to use hand bulb to refill VST, don't let electric fuel pump run in empty tank. And visually inspect fuel being drained.
 

bayrat

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"I get it on my 2 micron VST filters and the VST float and walls of VST tank, but so far no trace of it in my 2 micron racors. Meaning it occurs downstream of the racors and not from gas supply. "

Thats probably the most interesting observation that I've read on this subject so far. Based on that you would hope that Yamaha would come up with a fix that focuses on something more than just adding layer upon layer of filter. My engine is new so I haven't really gotten into it yet but heard that removing/ cleaning the VST on an f-250 is a real chore. And here I was hoping that changing / maintaining filters, adding additives would preclude having to do that. Oh, well...time to study the manual I guess.
 

Doc Stressor

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Re: fuel filter/water separator question

Yamaha has reformulated both Ring Free and their Fuel Stabilizer and Conditioner to protect fuel system metal components, including aluminum, from the corrosive effects of sulfates.

Ring Free PLUS

We took Ring Free, the proven engine deposit package, and made it even better. Our exclusive, synthetic PLUS formula provides superior deposit control, cleaning fuel injectors, carburetors, intake valves, intake ports and combustion chambers. Featuring metal filmers, it also protects silver solder, copper, aluminum and steel in a fuel system from the corrosive effects of ethanol sulfate salt.

The ethanol industry has also been required to reduce the amount of sulfur and sodium in their fuel products. But the present limits are still high enough to cause corrosion concern.

Sodium sulfate precipitate formation and filter clogging was a much greater problem before they lowered the acceptable limit for sulfur in fuel ethanol to 4 ppm.
 

bayrat

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"Yamaha has reformulated both Ring Free and their Fuel Stabilizer and Conditioner to protect fuel system metal components, including aluminum, from the corrosive effects of sulfates."

Wasn't aware of that..thanks for the info