What Happens with Contaminated Gasoline - Fuel pump screen clogged!

[martincom]

I sold my brother-in-law one of my 2004 Virage i the week of the Fourth of July. At the end of July, I receive a message from him that the jet ski I sold him was not running correctly. It would hesitate and die after it had been running 30 - 45 minutes.

At his vacation home, I test ran the Virage and sure enough, after about 15 minutes of running it would hesitate and die if you attempted to accelerate much beyond 3000 RPM. I returned to shore long enough to connect a fuel pressure gauge and route it out the rear seat storage compartment. It ran fine and operated well for another 5 minutes and then the issue re-occurred. The fuel pressure would drop off to 10 psi or lower when the problem occurred and would come back up again when the throttle was released. Next, I shut the engine down and floated for a minute or two. When I re-started it, it ran fine again for another 5 minutes.

I concluded he had re-filled the Virage with contaminated, dirty, gasoline and it was collecting around the filter. Shutting it down for a few minutes would result in the contaminates washing away from the filter, allowing normal operation, until they were drawn back around filter.

I reported my findings to which my brother-in-law responded the gas it was sold with must have been contaminated, as it was operating this way before he re-filled it. I could see where this was going. I told him I didn't want any hard feelings and I would buy it back. I bought it back, but the hard feelings came regardless.

I didn't have time to get to it until last week, when I was performing the end of season winterization on the others. It had about 3/4 of a tank fuel in it. I pulled the filler neck hose from the tank, expecting to see a bunch of contaminants floating around---nothing. I pumped the tank out, filtering the contents through a paper paint strainer funnel liner. The liner was clean. I removed the canister assembly and inspected the inside of the fuel tank. Very little, just some trace contaminants. I wiped out the inside of the fuel tank with paper towels, replacing the towels with each pass and inspecting them for contaminants--clean.

I inspected the filter at the bottom of the canister. There was nothing clinging to the screen or the filter element that was detectable. The filter was brown in color, but was that from contaminants or just from being saturated in gasoline?

I disassembled the canister and found traces of contamination within the canister:





I couldn't tell what it was for sure. At first, I was thinking the large piece was the stinger portion of a wasp body or a tree bud, but I can't state what it is with any certainty. The top side strainer, pictured in the photo, was not loaded with contaminants.

I continued inspecting the canister components and found the intake screen of the pump loaded with contaminants:



I cleaned the intake screen with a tooth brush and a flux brush in which I had trimmed down the bristle length. I brushed the contaminants on to a piece of paper for closer inspection and to photograph:



The large piece, in the upper right corner, is the wasp body/tree bud that was found in the canister body. This was all very minute contaminants. Once the gasoline dried, I ran my finger across the paper and I could not "feel" any of the contaminants. They were more like a slime than a particulate.

Below is a a photo of the cleaned pump intake screen. As you can see, the intake screen is a very fine mesh.



I did replace the filter at the base of the canister. It is a Carter STS-200. I sourced the replacement at the local NAPA store, which had to order it from a distant warehouse. Summit racing indicates they stock them on-hand.

Once back together, it was a few seconds of run time to clear the exhaust of water and then on to winterization. The test ride will not come until next summer, but I'm confident I resolved the problem.

The moral of this tale is to be sure to utilize clean fuel and clean storage containers.

[K447]

Hmmm. The fuel return flow on Ficht fuel pump goes directly into the inner body shell of the fuel pump.

Is it possible there was some contaminants/varnish from the old fuel hoses/injectors that paritially re-disolved and then flowed into the fuel pump?

Perhaps in a previous life the machine sat for a long time with some bad fuel that eventually clogged the pump?

Glad you found it. You may never know why/how that stuff came to be there.

[martincom]

All good possibilities K447, but not in this case. I owned that particular Virage for at least the four preceding years and operated it every season without issue.

[grumpy_steven]

I'm not an expert on gasoline, but I know from my experiences that gasoline with ethanol seems to leave a residue if left sitting too long without stabilizer. The residue forms a brownish gunk that can restrict fuel flow. Eventually, the residue will dry to a gritty, brownish-yellow substance that looks like dirty sand.

Here's a pic of the internal screen from a Yamaha carb in a ski that was left sitting with untreated fuel.

[HiPeRcO]

STICKIED!

[Myself]

I fixed one earlier this year like that, it's screen was packed with what appeared to be fibers from a deteriorating lower filter. It also would run great for 15-30 minutes then bog out and only idle. Let it sit a while and good to go for another 5 minutes.

[martincom]

I fixed one earlier this year like that, it's screen was packed with what appeared to be fibers from a deteriorating lower filter. It also would run great for 15-30 minutes then bog out and only idle. Let it sit a while and good to go for another 5 minutes.

Yes, I remembered reading about your issue and thank you for the heads up. It is why I didn't stop at just changing the filter at the bottom of the canister and disassembled to the point of inspecting the pump intake screen.

[swan]

Martincom, in our part of Australia we don't experience anything like the extreme cold that you do (we regard 40??F as 'cold'), but 'winterising' for periods of ski inactivity still makes sense down here. I understand that the 'short run prior to shut-down' process typically has two objectives: to exhaust coolant water and to distribute fogging oil.

I have wondered whether an alternate way to exhaust coolant water might be to undo the water inlet hose from the exhaust pipe, clamp the inlet hose at the forward end of the intake pipe (near the through-hull bearing) and apply compressed air to the water lines. Less convenient than running the engine briefly, I concede, but is it a viable alternative as a means to exhaust water?

Re this thread: I'm thankful that as part of my recent MSX140 rebuild I removed the fuel pump from its assembly (while securing the FPR) and cleaned the relatively inaccessible mesh screen!

[martincom]

Swan,

The purpose of briefly starting the engine, in the winterization process, when the PWC is out of the water, is to expel water from the exhaust system. Applying compressed air to the coolant lines won't do anything for us in that regard. Most of the exhaust system probably has large enough passages that any water remaining wouldn't be enough to damage anything. However, the resonator(s) are another issue and thus why the brief engine start.

The rest of the cooling system is self draining. The Direct Injection watercraft need to be stored with the bow up at least 10 degrees, as set forth in the Operator's Manual. This prevents any latent water remaining in the cooling system from collecting in the stator water jacket. If not, any water that collects in the stator water jacket may expand enough when frozen to force out the cover gasket, resulting in a water leak the following season. I've never seen a casting split as a result, but I have seen more than one gasket pushed out.

A nearby jet ski shop always blows down the cooling lines with compressed air to prevent damage claims from customers who neglect to store their watercraft with the bow up 10 degrees. I never do with mine and have never had an issue, but I've always stored my PWCs & boats with the trailer tongue jack wound all the way up to provide for draining of any water that may inadvertently collect in them during storage. One of those ounce of prevention is worth a pound of cure practices.

[swan]

Thank you for that insight, martincom. As you suggest, elevating the front of the trailer is a simple process.

[K447]

Thank you for that insight, martincom. As you suggest, elevating the front of the trailer is a simple process.

Ten degrees bow up can be more than a trailer jack alone can achieve.

I agree that elevating the trailer with the jack is a fine idea.

For my own watercraft I would slide the hull back on the bunks, just enough to bias the balance to the rear. Latch the winch strap, then raise the nose until the ride plate touches the ground (or real close). Then I would rev the engine firmly several times and confirm the water is really leaving the exhaust.

Good time to drain the hull while it is pointed at the sky

I would sometimes spray cleaner into the hull, scrub it around, then do the tilt up and rinse inside with a hose. THEN blow the exhaust out and proceed to winterize. Seat off air dry in the sun can be good, prior to storage.

When all done, a saw horse (or similar) placed under the tongue can maintain the angle and keep the footwells drained. Winch the hull forward as needed to make the trailer stable.

[martincom]

Here in MN, if I leave the seat off to air dry in the sun, the hull will be full of leaves and pine needles before it ever dries. So I fold a shop towel in to a square and place it on top of the seat & cargo latches, so they don't latch. This provides some added air flow to dry thing outs and prevent mildew while in storage.

I wash mine after winterizing and place a broom handle under the trailer tongue to keep it propped up until the water drains/dries.

[N2Motors]

Guys - all great feedback. I have a ray of optimism (albeit reserved) that it could be the fuel.

I'll check the fuel pump screens posted in the photos and let you know what I find out. Circle back post the weekend.

[nmpeter]

I put a 50 watt incandescent shop light into the hull to make sure it dries out. leaving a seat off around here for an extended length of time is a sure rattlesnake/packrat atractor