F225 TXRC bogging down - fuel rail pressure question

[pstephens46]

In most Yams the VST is vented to the atmosphere via the charcoal cannister in the vapor recovery system.

I seem to recall some early models not using the vapor recovery system simply vented the VST directly to the atmosphere.

Where is the F filter located in this diagram?

[fairdeal]

it would be the filter immediately before the float chamber

although given the box surrounding several parts,
that schematic may represent a later version where filter, check valve, etc are actually "in the VST"

[boscoe99]

Where is the F filter located in this diagram?

With respect to TOS, a moderator sent me a PM and thanked me for not responding to some apparent insults posted by another forum member. I did not see the insulting posts. Appears the moderator might have removed them.

It is a zoo over there. I kind of enjoy it is a perverse sort of way. I like stirring some of those folks up. Seems that you take a bit of pleasure as well.

fairdeal stays above the fray.

[walleye1]

The Hull Truth?

[pstephens46]

With respect to TOS, a moderator sent me a PM and thanked me for not responding to some apparent insults posted by another forum member. I did not see the insulting posts. Appears the moderator might have removed them.

It is a zoo over there. I kind of enjoy it is a perverse sort of way. I like stirring some of those folks up. Seems that you take a bit of pleasure as well.

fairdeal stays above the fray.

I get so confused with all the tubes around the VST. I couldn't remember if the "F filter" was after or before the HP pump. If after, I liked the idea of a clear replaceable filter. If it could handle pressure I suppose.

The Hull Truth. The simplest questions by OPs become just a muckfest. "My Seastar seals are leaking". Then we are off and running....

Yes it's fun to poke sometimes.

[Crazy Train]

One potential source (I read about this on another forum) is the HP pump itself. Moisture contained within the hygroscopic ethanol rusts the internal metal components of the Hi PSI pump. As I understand it, you don't need suspended, free water in the fuel, just moisture contained within the E10. That moisture corrodes the pumps internals which then get pumped out to the injectors. The fuel returned to the VST from the fuel injector supply loop - (wrong nomenclature I'm sure, but you get the idea) contains these ruts bits along with the little bits of crap sloughed off by the internal degradation of the fuel hose. There is a vendor who sells a replacement pump which contains zero metal. Supposedly its got ceramic guts. I cannot vouch for it.

One guy actually cut an old HP pump open and discovered it rusting out internally. So, you can change all the filters short of the VST all you want, but you still can't prevent detritus from gumming up the VST fuel pump filter or the injector screens. At least, this is how it appears to me.

On my boat, the external Racor was completely clean. The first stage YAM filter was fine. Yet there was crap in the VST screen. I did not cut open the F filter, I just tossed and replaced it. Another 30 dollar bill.

I am giving consideration to adding a simple glass see-through in place of the F filter. If I can relocate it to a more sensible location I will.

I have finally found the time to pull out the VST and the HP pump filter. The bottom of the VST had a small accumulation of reddish-sandy colored particles with a few black specs. The HP pump filter was about 50 percent clogged with the same type of particles. Wish I could figure out how to post photos, but that filter is now clean. I also pulled the fuel injectors and had them cleaned. The injectors ranged from zero to about 10 percent flow rate degradation (58 out of 64). The old injector screens had some particulate matter build-up, but nothing of what I would call significant. Of note, there are some screws on the inside portion of the VST lid that have some corrosion; that corrosion seems to match the particulate matter at the bottom of the VST and the HP pump. As in the OLDMAKO quote above, my RACOR was clean, the on-engine filter was clean, but the VST was clogged - meaning the VST eroding/corroding and clogging itself. So, I am racking my engine bogging issue up to a clogged HP pump filter. Time to put it all back together and test run it.

[pstephens46]

I have finally found the time to pull out the VST and the HP pump filter. The bottom of the VST had a small accumulation of reddish-sandy colored particles with a few black specs. The HP pump filter was about 50 percent clogged with the same type of particles. Wish I could figure out how to post photos, but that filter is now clean. I also pulled the fuel injectors and had them cleaned. The injectors ranged from zero to about 10 percent flow rate degradation (58 out of 64). The old injector screens had some particulate matter build-up, but nothing of what I would call significant. Of note, there are some screws on the inside portion of the VST lid that have some corrosion; that corrosion seems to match the particulate matter at the bottom of the VST and the HP pump. As in the OLDMAKO quote above, my RACOR was clean, the on-engine filter was clean, but the VST was clogged - meaning the VST eroding/corroding and clogging itself. So, I am racking my engine bogging issue up to a clogged HP pump filter. Time to put it all back together and test run it.

Did anyone ever ask what fuel you are using? Ethanol? With extended storage periods?

[TownsendsFJR1300]

Per RB, that debris is from the brushes of the HP pump

[99yam40]

Per RB, that debris is from the brushes of the HP pump

redish color may be rust

[pstephens46]

redish color may be rust

Which made me wonder what fuel sitting how long?

[Crazy Train]

Did anyone ever ask what fuel you are using? Ethanol? With extended storage periods?

I am using ethanol fuel (10 percent ethanol) treated with sta-bil marine (the blue stuff). Tough to find non-ethanol fuel here (Maryland). The fuel has been in the tank since last spring. I am in the process of recycling the fuel out of the boat and into my truck. Since the truck is running fine, I don't attribute the issue to old fuel.

[pstephens46]

I am using ethanol fuel (10 percent ethanol) treated with sta-bil marine (the blue stuff). Tough to find non-ethanol fuel here (Maryland). The fuel has been in the tank since last spring. I am in the process of recycling the fuel out of the boat and into my truck. Since the truck is running fine, I don't attribute the issue to old fuel.

I might attribute HP pump corrosion to ethanol. How many hours on your motor?

I say this offhand based on my experience. May have some relevance or not. I disassembled my 11 year old VST for the first time and found nothing. 540 hours at the time. Only use non-ethanol. Fairdeal runs ethanol with no issues. But typically runs his boat 300+ hours a year. Not much sitting around.

You may be doing all you can with ethanol being the only fuel available. Gets cold up there. Hard to do much in January or February to cycle the fuel.

[Crazy Train]

redish color may be rust

I cleaned off the two screws I mention above that are on the inside of the lid of the VST. Those two screws were covered with a reddish-white substance - the same sand-like substance that was in my HP pump filter. Of note, those two screws are steel (magnetic) that hold two stainless steel plates on to the cast-aluminum VST lid. Very possible it is rust. Another theory: based upon the appearance of the reddish-white substance (almost granular), and the dissimilar metals, maybe galvanic action is causing the reddish white substance to form. Regardless of how it is formed, the substance is falling down into the bottom of the VST and clogging the HP pump filter.

[Crazy Train]

Photos of the two screws.

[Crazy Train]

I might attribute HP pump corrosion to ethanol. How many hours on your motor?

I say this offhand based on my experience. May have some relevance or not. I disassembled my 11 year old VST for the first time and found nothing. 540 hours at the time. Only use non-ethanol. Fairdeal runs ethanol with no issues. But typically runs his boat 300+ hours a year. Not much sitting around.

You may be doing all you can with ethanol being the only fuel available. Gets cold up there. Hard to do much in January or February to cycle the fuel.

Thanks 46: 704 hours on the motor. I cannot rule out fuel contamination due to particles from inside the HP pump, but it is highly, highly likely that those two screws are shedding particles into the VST. Attached is a photo of one of the screws after a moderately-light scrubbing with a brass brush. Thanks!