Fueling/Motor problems - would appreciace input

[mbo_1971]

Hey folks. So the last 2 times out, I have had what I believe is a fueling issue with my boat and am wondering if anyone has any thought before I put her in the shop.

Setup:
Boat - '83 SeaCraft 20' SuperFisherman (so we know thats not the problem)
Motor - 2001 Yami 200 HPDI
Fueling System - Yami 10micron fuel filter which has new 3/8" fuel supply from the filter to the fuel bulb (also brand new) and through to the motor. Fill, vent and supply hoses are brand new (alcohol-friendly). Supply from the tank is 1/4" hose
Tank is original as is the fuel pickup valve. Tank has been pressure tested and has no leaks

Symptoms
Issue does not surface until I have been running for a while - I run 3600 rpm for about 30 min to get from Harbor out to the mouth of the Patapsco. Both times I have had no issues until I hit the mouth of the river (or 30 min of somewhat hard running). Motor will choke on itself, sputter and then cut out. I can crank it back up and will start idle but under load/throttle up it will choke again. Both times as I have looked at the fuel bulb, it has been sucked flat. If I unscrew the filter, there is a great suction release but there is fuel in the filter. I would have thought that with a flat ball, there would have been no fuel in the filter. This said, it was not completely full. Filter was brand new first time and was replaced (thinking it was a clog issue) only to have the issue repeat itself. I have not dumped the contents of the filter into a jar to see if there is water in the gas.

Troubleshooting
I was thinking I would start by hooking up a remote tank past the current fuel bulb and run it directly to the tank. This should tell me if this is a motor or a fueling issue. From there, I would work my way back to the main tank by adding a piece of the fuel system each trial period to see if i can isolate the issue.

I think that the issue is either 1) too small a fuel hose from the filter the the fuel bulb and through to the motor or 2) a bad fuel pickup valve out of the main tank. That is the only piece of the fueling system that has not been R&R'd at this point.

Any thoughts/similar experiences would be helpful. Anything I could clarify, please let me know. I just put this reconditioned boat in the water and am dreadfully disappointed that I can not go fishing at this point. Thanks in advance for any assistance here.

Matt

[gofastsandman]

Read that book recently. Get a vacuum guage with a t on the end and work your way back. I replaced my tank to filter line w/ 3/8 id A1 under deck rated hose. My 30 hr filter was the culprit. Your suspects are the vent hose being kinked or vent blocked. Pickup is next on the list. I have 3/8 id alluminum tubes w notched bottoms to release any gremlins. The nylon ones w/ screens get clogged and blow motors. Change it. Use anti seize when reinstalling pick up. Permatex makes a good one. The e 10 gas we got in August cleaned out my orig tank and clogged the 30 hr Racor.

No worries, we`ll get you back on the fish in no time.
GFS

[Blue_Heron]

I would say that if the fuel bulb is being sucked flat, the problem is not in the motor. My guess would be a blockage in the tank or the fuel line upstream of the filter, but my money is on an obstruction at the tank pickup. I had a similar experience with my flats skiff recently. The filter was clear, but when I took off the line to the tank and tried to blow through it, it was blocked. I cleared it with compressed air and it's been fine since. I'm still not sure what caused the problem. The tank looked pristine when I pulled the sending unit and looked inside. If your tank has a fine screen on the pickup, it could be accumulating small flakes of crud over time until it stops up.
Dave

[eggsuckindog]

Here is the ticket - Isolate and Eliminate
Its not a motor issue period - forget that
Now with the bulb being sucked flat - its either the bulb - the tank pickup - an anti syphon valve or the vent.
Do one at a time so you isolate and eliminate each item - first when it sucks the bulb flat open the tank fill - you get gas its the vent, you just vented it.
Next - if thats not it when it sucks flat blow back through the line - that will clear the tank pickup, should be easy to blow and you should here bubbles
The anti syphon valve is in the tank fitting and yes they do cause issues, personally I would take it out and use a straight fitting but I'm a rebel.
The bulb itself can be checked by getting the motor started and warm, shut it down and remove the bulb itself and try it.
If none of that works try bypassing the filter

Its between the tank and the motor somewhere - I don't like the 1/4" line though should bigger IMHO but not the issue I don't think

That will keep you from buying anything before you find out what it is - isolate and eliminate - hope this helps

[gss036]

I recently had problems on my 23WA w/bulbs sucked flat, and turned out to be a really dirty tank. The junk from the tank was filling up the pick up or else clogged the Racor filter. I ended up replacing the tank because it was seeping gas into the foam.
Make sure the inside part of the tank is clean.

[mbo_1971]

Thanks for all the thoughts here guys. Just to clarify a few things:

Line sizes - I believe I misspoke. They are 3/8" from the tank to the filter and 5/16" from the filter to the bulb and then through to the motor.

One other thing - when this issue occurred the first time, I was concerned it was the filter so I disconnected the fuel supply to the filter, blew back through it and then connected directly to the fuel bulb. Ran no issues all the way back to port. Next time out i reconnected the line to the now new filter and after 30 min of running, same issue. That set me down the line of thinking that it had to be the filter. After calling the folks that sold me the motor, he said no way it is the filter (it is the proper size for that motor 100% guarantee). He suggested anti-siphon valve, but I really dont know what/where that is.

Not sure where the anti-siphon valve is - is it in or attached to the elbow coming out of the tank to which the supply line to running to the filter is attached? I understand these can clog due to e10. That elbow and the line that extends from it down into the tank to pick up gas were the only items that was not replaced in my fuel system.

I have not checked venting - but to that end, if i run without the fuel cap on, dont i run a pretty big risk of getting water in the fuel?

One other question - i know small outboards have a clip that helps hold the fuel line for a remote tank on. Is is likely that my motor would have one of these? Since the mechanic installed the corrugated hose that neatens things up and houses the battery, shift linkages and fuel and oil lines, I can not tell if my motor would have one. I would think not, but just wanted to bounce it off you guys.

Thanks again for the comebacks.

Matt

[ReelToy]

Go with ES Dogs suggestion anti siphon valve is just another pita. Problem lies between tank pickup and filter. The Yamaha 10 micron filter is the best on the market right now. Alcohol in gas is causing lots of problems seen quite a few hoses separating inside and closing off inside hose. Also plugging injectors.

[Fr. Frank]

Dixon (ESD) is right on.
The original tank uses a 3/8" pickup fitting, so the line to the filter should be 3/8". Any motor capable of pulling over 12 gph should be using a 3/8" fuel feed all the way to the motor, not a 5/16".

The culprit will almost certainly be the fuel pickup or anti-siphon valve. But that's not the underlying issue.
The service issue is the question of what is causing the pickup to clog or the anti-siphon valve to malfunction. You can replace the AS valve with a direct flow 90* fitting, and a new pickup line, which are fairly simple tasks.

The problem is that if you've currently got trash in the tank blocking the pickup or restricting it, it'll eventually fail again even with the new hardware. My recommendation is to go ahead and pull, clean, and test the tank AND put in the new tank hardware.

[castalot]

this may seen stupid but you are using new gas not gas that has been sitting any time when i bought my boat it came with 80 gals of old gas that would run the engines good until they fully warmed up then they would "bog" down to about 1200rpm and they would't come back until next test day refilled with new fuel and a good dose of startron and all is well good luck

[gofastsandman]

My pickup looked just like yours. It`s a welded threaded collar. I too was afraid. Use a little penetrating oil overnight. Mine backed out pretty easily after I put a little muscle to it. Don`t forget the anti-sieze. They should of used it when made and they look scary, but mine came right out. The other pickup is for twins.
VST`s are notorious on Yamis
GFS