VST Maintence

[Dire Straits]

I have a 2002 SX200trra outboard.....What maintence should I be performing on the VST and how often.

[boscoe99]

Routine maintenance is not normally specified by Yamaha for the VST. Maintenance, if required, is "on condition". That is, if it ain't broke, don't fix it.

In theory, only clean filtered fuel should make its way to the VST. The quality of the fuel, and the amount of the fuel, that flows through the VST filter will affect to what extent, if any, the VST filter becomes clogged.

Now having said all of this, there is a drain plug in the VST float body. I would crack that open and drain the fuel to see what the fuel looks like and what may be in there. If the fuel is clean then I would leave well enough alone. If water and/or debris comes out then you have to decide if it is necessary to open the VST up for an inspection.

With the VST drain opened up (you don't have to remove the drain plug entirely) press the Schrader valve to allow air in which will help the fuel come out. Make sure to refill the VST before turning the key on. Not good to run the electric pump without it being submerged in gasoline.

[rodbolt17]

one of us had to many liquor drinks.

that VST filter needs cleaning every 100 hrs or so.

pump debris clogs it.

a simple thing.
drain the VST.
use a can of carb cleaner.

bend that red tube 90*.

stick it into the drain hole.
spray the filter.

[boscoe99]

This is an SX motor. What pump debris? Yes, there are three pumps but they are pretty reliable and not prone to throwing out debris.

Anyway, it is Yam that does not call for routine VST maintenance on an SX model. Not me.

Now maybe it was because my Merc 175 EFI only needed one lift pump, instead of three, but with 600 hours plus run time over 5 years, the VST filter did not need to be serviced.

By an Etec and from what BRP says there is no maintenance at all needed for many years.

[Nautical]

Excellent points.. In addition, I think that when ethanol is used and there is a lay up , the water separates in the VST.The water will interact with the aluminum in the pump casing and form a scale (corrosion). This scale will flake off and if smaller enough will get pumped to the fuel rail , then to injectors. there are filters that this scale has to go through but sometimes it can clog them. I suppose if you lay up the engine might be a good idea to drain VST of fuel and add mineral spirits to prevent corrosion.

[Kirk Gibson]

since we are talking about it

Rodbolt, would it hurt to spray the carb cleaner in the VST drain hose on my F150s before the start of my season. I don't have any problems just want to keep it that way. Thanks

[rodbolt17]

on the F150 , you cant hit the filter.

on the SX like ALL Yamaha electric pumps, they are a blow through design.

means gasoline leaves the pump rotor area, flows across the motor windings, flows across the commutator and brushs then out the outlet.

its the brush dust that can clog injector filters and be returned to the VST to clog VST filters.

don't believe me on the maint??? look at the maint sticky.

[TownsendsFJR1300]

on the F150 , you cant hit the filter.

on the SX like ALL Yamaha electric pumps, they are a blow through design.

means gasoline leaves the pump rotor area, flows across the motor windings, flows across the commutator and brushs then out the outlet.

its the brush dust that can clog injector filters and be returned to the VST to clog VST filters.

While on the subject, your opinion please.

I'll drain the VST (F150) thru the hose (maybe every 4th time out) and catch what comes out in a clean tuna fish can.

On occassion, I'll blow back (by mouth), in the hose, until I hear it bubble inside to flush any debris possibly left behind.

A pump or two of the primer for a final flush. Its been spotless for at least two years, no debris whatsoever, fuel nice and clean, clear, smells fresh.

Would you still recommend the carb cleaner to the VST tank as noted above? (Ringfree is used regualrly as well).

**Basically, no possibility of screwing up(melting/damaging o-rings, etc) anything??

Thanks ahead of time..

[Dire Straits]

Excellent points.. In addition, I think that when ethanol is used and there is a lay up , the water separates in the VST.The water will interact with the aluminum in the pump casing and form a scale (corrosion). This scale will flake off and if smaller enough will get pumped to the fuel rail , then to injectors. there are filters that this scale has to go through but sometimes it can clog them. I suppose if you lay up the engine might be a good idea to drain VST of fuel and add mineral spirits to prevent corrosion.

At the end of the season (Nov) I run a 2 gal. external gas tank with fresh gas mixed with marine St-Bal connected directly to the feed hose of the engines primary fuel filter. The lay up would be until May. Do you think that this method would surfice draining the VST and adding mineral spirits?

[boscoe99]

on the F150 , you cant hit the filter.

on the SX like ALL Yamaha electric pumps, they are a blow through design.

means gasoline leaves the pump rotor area, flows across the motor windings, flows across the commutator and brushs then out the outlet.

its the brush dust that can clog injector filters and be returned to the VST to clog VST filters.

don't believe me on the maint??? look at the maint sticky.

Where specifically in the two stroke, non-HPDI, maintenance schedule does it refer to the VST filter. Maybe I am not seeing so well.

What about the filter baskets in the fuel injectors? What about maintenance for them?

Too bad Yamaha does not know how to spell separator.

[Nautical]

At the end of the season (Nov) I run a 2 gal. external gas tank with fresh gas mixed with marine St-Bal connected directly to the feed hose of the engines primary fuel filter. The lay up would be until May. Do you think that this method would surfice draining the VST and adding mineral spirits?

I would follow your service manual for extended lay up during off season. I do think your idea would work and would avoid absorbed water normally associated in ethanol fuel from separating and corroding any aluminum.

[Christian]

I opened the VST on my FT60. The filter was black. It was a uniform colour so I almost put it back until someone more on the ball said hang on, proceeded to clean it with injector cleaner. Now its white. Found black gunk on both sides of the filter. Tested the injectors and they leaked at 40psi. Probably also gummed up with same. Had them Ultrasonically cleaned at Mr. Injector (UK).

Why doesn't Yamaha have a 3 or even a 1 micron filter inline just before the fuel rail??

[TownsendsFJR1300]

Why doesn't Yamaha have a 3 or even a 1 micron filter inline just before the fuel rail??

Job security in the service department...

That'd make too much sense...

[bajakeith]

ethanol

In the calif. market I'm seeing the VST tanks getting ate and plugging the VST filter... some where (service manual) I read a while back the filter is non serviceable...BS,,I have cleaned many with carb cleaner and works like new..just remember to spray backwards of normal direction for a good cleaning...

[TownsendsFJR1300]

In the calif. market I'm seeing the VST tanks getting ate and plugging the VST filter... some where (service manual) I read a while back the filter is non serviceable...BS,,I have cleaned many with carb cleaner and works like new..just remember to spray backwards of normal direction for a good cleaning...

Is it varnishing up inside or ?

I ask in that I never had mine apart, F150, (the shop did once under warranty but left it as it was fine years ago). The engine runs great, I do drain the VST occassionally, noted earlier, fuel is clean, clear, smells good.

Rodbolt mentioned simply spraying carb cleaner with the nozzle bent leat a 90 degree angle to clean it inside (and let it drain), while installed

Carb cleaner can be aggressive and I wanted to make sure there was NO CHANCE of me melting/damaging something with the carb cleaner, o-rings, etc.

Again as noted earlier, I use RingFree on the heavy side, K100 (excellent product IME) and marine Non-ethonol fuel.