F225 dies whenever and boat bogs down qt 3500

[Justmeagain]

I have a 2004 Yamaha F225TXRC. There are 330 hours on the engine. After spending $3500 at a Cocoa, Fl. place, my issue remains the same. I'm not the type to return to the scene of a crime, or if a Dr. cut off my left arm instead of left leg. Why would you expect better results?

Symptoms: I used the boat infrequently, mostly run the engine monthly. The fuel tank was drained and cleaned. The engine ran well at idle at the dock for a time, now it will struggle and die. My son noticed that the fuel filter bowl in the engine drops below the filter element about half way down the bowl just before it dies. I can turn the key off and it will restart and run immediately. When it first starts to struggle, pumping the fuel primer bulb helps.

Actions: The shop did a full annual service. Injectors were removed and ultrasonic cleaned, one was replaced with a new Yamaha injector. Plugs are new (I did that) and good. Removed the VST and cleaned it. The fuel pumps were tested on the bench. They did run the boat on open water tests. During the open water test, the engine bogged down at 3500 RPM. Fuel pressure fluctuated, drops to 35PSI under load. High pressure fuel pump was replaced and the VST, screens cleaned.

The fuel filter is new. It has a bowl and drained several oz. and it was clear. New fuel is non-ethanol. I do have a Yamaha fuel flow sending unit installed just after the fuel filter. I removed it, I'm wondering now if the paddle wheel is sticking. That could account for the sudden stall after traveling 1/2 mile but not the 3500 RPM limit. I also noted when the engine wants to die, pushing up the throttle up only worsens the situation.

Any insight would be appreciated.

Also, any experience with the diagnostic sets (pigtail and SW) available from E-bay vendors? Seems they are all out of the country.

[gunz@pc]

have you tried this

Isolate the problem from the boat or engine side. Get a portable tank and hook it up to the engine fuel filter. Go run it if you get the same problem its engine side if it runs WOT its Boat side. At least you will start narrowing your search. I've seen fuel filters missing o rings, water sep filters not tight, primer bulbs on wrong, hose clamps/tie straps loose, restrictions in pickups.

Good luck,
Gunz

[rodbolt17]

sounds to me like your simply running out of gas.
that hull has at least 2 tanks.
at least 1 on or in the hull.
the other is called a VST.
if the low pressure pump fuse blows it wont run.
if the relief valve tie strapped on the side of the vst leaks it will typically run only if you can keep it above 1200 RPM.
it is a simple 12v pump that has 12v + anytime the key is on.
the black pump wire is the ground.
the ground is ECU con*****ed.
below 1200 RPM it cycles 10 sec on 20 sec off.
by pumping the primer your simply refilling the tank on the engine.

[Justmeagain]

Engine quits whenever and bogs down at 3500RPM.

Thanks for the input, I need to provide more info.
The maintenance log states that it was run on a separate tank. I also ran it on a portable tank of fresh fuel, same problem but the heat here in August convinced me to throw in the towel and let the pro's do it.
The fuel tank was drained (90 gal) and cleaned. Issue is the fuel sending unit does not seem to be disturbed. How else would it be "cleaned" if not through that hole?
Starting and running the motor at idle is not an issue, unless it decides to quit after a few or 15-20 minutes or whenever. I made a quick attempt at full throttle in a "slow speed" zone and felt it bog down. Didn't continue.
The high pressure pump was replaced. The VST was cleaned twice to include any screens to include VST and all injectors. I do not see a reference where the low pressure pump was replaced. I read somewhere that O'Riley's auto stores has a low pressure pump that can be used with little modification.
All of the electrical connectors were inspected and reconnected.
I removed the Fuel Management sending unit from the fuel feed, wondering if the vane is sticking. Engine started well, ran at the lift with RPM raging from idle to 1200RPM increasing the RPMs and letting it run at that speed. No open water trial.

Thanks again.

[99yam40]

I would think someone would have monitored the lift/low pressure fuel pump output to make sure it stayed in spec along with the high pressure before replacing the HP pump to figure out if the LP pump was running as it should while the HP dropped its pressure.

good chance the HP pump was not the problem if the VST was running low on fuel

[rodbolt17]

drop the gearcase in the water.
remove the hood.
use the primer to insure the VST and engine filter are full.
start the engine and observe the filter.
you should see the level rise and fall as the lift pump cycles.
if you have an AL water separator head remove the filter and check for corrosion on the gasket surface as well.
if you see the filter cup fuel level fall then the lift pump is trying.
you will/or should, see the fuel in the cup rise and fall as the lift pump cycles 10 sec on 20 sec off.

[99yam40]

Rod I kind of sounds like it will run OK at low RPM but not at high, more like a restriction or sucking air maybe

[ECGOERES]

i saw this in a brand x motor i used the fuel bulb to pump fuel to the different hose ends starting at fuel bulb and observing flow . restriction in my case was in fuel line where it entered motor housing was corroded closed , I changed all filters and pumps first , In the end the fuel bulb was the best tool to find this problem

[scofflaw]

Had a similar issue, decided to replace the fuel bulb first...Bingo

[boscoe99]

Being the gauge enthusiast that I am (there can be no such thing as too many gauges) my outboard motors in the past have been retrofit with both a fuel supply vacuum gauge and a fuel pressure gauge. If I had a problem it would have been easy to spot. In fact, when I first got my boat the Mercury motor would stall and die. From time to time. An intermittent problem. Installed a fuel system vacuum gauge and then one day the motor quit. Looked at the vacuum gauge and it was indicating well over 10" Hg. Told me the fuel supply was the problem. Finally found a fuel hose to be failing internally.

Now I will admit that I get as much pleasure out of adding "systems" to my boat and motors, and watching what is going on in action, as I do in using the boat. If I did not like working on boats and motors as much as I do I doubt that I would own one. Too much trouble otherwise.

[Justmeagain]

F225 bogs down. Forgot about this

Thank you all for your help.
8-9 years ago I bought a Yamaha Fuel Management System. Yesterday I removed the sending unit from the fuel system (they need to make bigger access hatches for mature people). It is hard plumbed into the filter. The engine started well and sounded better. I have a second sending unit but did not put it in (yet).

Still on the lift but with the engine in the water worked the throttle incrementally up to 5400 RPM and left it there for 10 minutes without a hickup. RPM did vary 100 RPM.

Open water trials tomorrow with son and we'll see how this goes. Sitting in the boat while it ran, I started to wonder if it was smart to tie off the boat to dock pilings or cleats, pull against them to give it a 'load'. It's several miles to where I can open up the throttle.

One other observation. When I shut down in the past, I heard 4-6 clicking noises like a relay. I don't hear it now. Any ideas?

Happy New Year!

[pstephens46]

Not a big fan of revving engine in idle much. Better to have a load under normal conditions IMO. Don't tie off to dock to create a load...
You could easily break something! Including cleats, docks, other boats or your own head......

[TownsendsFJR1300]

Running with no load really isn't going to tell you much.

If your on a 4 post lift (cradle, not davits) where the boat is fairly secure, and your issue starts at 3,500 RPM's, you can probably lower the boat / engine enough in the water so the prop has load (and plenty of water).

Lower just enough so the hull is NOT FLOATING (far from it), stick it in gear and then throttle up slowly in gear. You can trim the engine up some for more RPM's if necessary.

It certainly wouldn't hurt to tie off the cradle to the posts(that will want to move forward) as well as the transom lift hooks also to the posts.

Again, go slow, I wouldn't go full throttle W/O the boat underway, but should give you an idea with some load...

[99yam40]

they make test wheels to run motors with a load without the boat moving.

running a boat/motor at high load/RPM in gear with your normal prop on it not moving, is overloading the motor.( not normal)

I guess the clicking would be from the IAC, if you are not hearing the IAC resetting at shut down anymore I would look into that, as it could take out the ECU if it is stuck
Should not have anything to do with the problem at higher RPMs thou.
Hopefully someone with more knowledge on that will chime in on that

[Justmeagain]

engine stalls

Thanks again to all.
Family here tomorrow and we'll do the trials. Just annoying having to put-put for 45 minutes because of Manatees. Oh well.

The boat is on a lift sitting on bunks. I have pilings at the 4 corners. Most secure would be tying on the bow ring, going to 2 pilings (V configuration) and loading in reverse. I could also go from the bow ring to the pilings at the stern. Not too worried about cracking my head, problem will be fixed (for me).

One favor please. I worked for the Army (Civil Service) for 38 years most in field support and Project Management and we have a bunch of acronyms. When I start talking in acronyms at home, my wife starts in acronym of medical terms and the conversation stops. Some habits are tough to stop.