2008 F60 Stall

[kaliann1]

I replaced the electric fuel pump because I thought it was the problem.
Scenario: I was cruising at about 4,500 RPM. When I throttled back to begin docking the motor stalled. When I tried to restart it would only crank. The gas gauge was showing 1/4 tank about 5 gal. I fiddled with it for a while and it started. I thought that a circuit breaker was the problem. When I went to return to my trailer, it went about 1/4 Mi. and stalled again. This time it was not while throttling back. The next day, after towing, and all that goes with it, I hit the starter and it fired up like nothing was wrong. So I replaced the electric fuel pump.To test it, I put the lower unit in water and ran it for 15 or so minutes, all seemed well. I goosed it a few times,still OK.Then I took it up to 4,500 RPM for a couple minutes and throttled back and it stalled again and would not start.I tried it again today it runs for about 1/2 second and will not keep running. The test was under no load in neutral. Any ideas as to what the cause of this problem is?
Thanks in advance

.

[panasonic]

Hello,

Please provide the exact engine model and serial number information found on the data plate on the transom bracket.

In your description of the problem you say it is stalling. Is it shutting down slowly, like running out of fuel, or just suddenly shutting down?

Why do you think it was a fuse problem?

You have to do some basic trouble shooting such as:
Are the spark plugs firing, is there fuel pressure at the fuel injector rail, have you inspected the wiring for loose and corroded connections.

Until you can supply some of this information then the members here can only guess what may be wrong.

[rejesterd]

The fact that it's hard to start once it stalls.. that points to the vapor solenoid valve. It could be sticking open and letting fuel vapors re-enter through the air intake when it shouldn't be. There's a vacuum test you can perform on the solenoid valve which is described in the service manual. Also a resistance test. It's not an easy test to perform, unfortunately because the measurements have to be taken at the same time.. so you need to make some kind of adapter to allow the solenoid valve to remain plugged while taking the resistance measurement.

However you have multiple symptoms, as you said that lately it can't even stay running. So obviously you need to work on that issue before the stalling issue. Check that your fuel tank is venting properly. Inspect the mechanical fuel pump to make sure it's valves & diaphragm are ok. Remove the fuel filter cup and empty the contents into a clear container. Replace the fuel filter if you haven't done so recently. Do a simple spark test with a spark tester and replace the current spark plugs. Then take a look at the condition of the old ones after you replace them.

Basically, try to rule out spark/ignition first, then go through the fuel system. That means the fuel tank fitting, the primer bulb, the main fuel joint, the fuel filter, the mechanical pump, the fuel strainer, the VST internal filter, and the injectors themselves (which can get clogged). You can measure the fuel pressure as well (the service manual has specs for that), which, if it's low, is pretty much a smoking gun that tells you something is wrong in the fuel system somewhere.

[rejesterd]

Also, if you can get it to idle in neutral again, it would probably be worth doing a de-carb treatment through the air intake. It's possible that carbon buildup is playing a significant role here. You just need to remove the intake silencer (2 bolts) to expose the throttle plate. Yamaha makes something called just "Combustion Chamber Cleaner", but there are tons of these products out there. I used CRC Marine tuner, as an example. I doubt carbon is your only enemy right now, but this is an inexpensive thing to do and it could help. You can also take some electrical parts cleaner (often called MAF sensor cleaner at auto parts stores) and spray into the ISC valve inlet (which you cannot see, but you can feel with your finger if you reach behind the intake manifold).

[kaliann1]

Hello to you also, This is what's on the data plate 6C5 F607 L RL1030155 H. It shuts down instantly, like it would if the key was switched off. The reason I checked the breakers was because I was grabbing at straws at that time, and I know one of the first things to do when trouble shooting is to check electrical connections. I don't have a fuel pressure gauge, but I would think with a new electric fuel pump that should be good. I am thinking about looking at the lift pump today.
Thanks for your interest

[kaliann1]

Today 10/20/19 I went through the fuel system. From the gas tank cap on. When I got to the fuel pressure regulator valve, part # 9 on the vapor canister blowup view, it is mounted on top of the vapor canister, it has a #1200-13F40 on it. I discovered it was open, I could blow air through the in side and it would pass through. I thought that it should be closed when no vacuum is present. I spread some WD40 in the or-faces and used compressed air to free it up. The motor started. I might be on to something. Rain is holding me up for now. A friend has a fuel pressure gauge. My next step will be running it With the gauge attached. Has anyone else had a problem with the fuel pressure regulator valve?
Thanks again

[rejesterd]

Yes, you should be able to blow through it at 10 psi or more. Once you hook up the pressure gauge, you can apply a vacuum pressure to the regulator. If it's working correctly, the fuel pressure should drop. You can also try disconnecting the accelerator line while idling and see if the pressure increases by about 5 psi.

[pstephens46]

Man, I really have some serious concerns about the future of this forum.

[99yam40]

Yes, you should be able to blow through it at 10 psi or more. Once you hook up the pressure gauge, you can apply a vacuum pressure to the regulator. If it's working correctly, the fuel pressure should drop. You can also try disconnecting the accelerator line while idling and see if the pressure increases by about 5 psi.

That confused me, so I am guessing it looks confusing to a lot of others

[rejesterd]

That confused me, so I am guessing it looks confusing to a lot of others

Once the pressure reaches 10 psi, fuel can start flowing through the regulator. The accelerator line (attached to the air intake) keeps the pressure about 5 psi less than it would normally get to. This is to allow for greater fuel pressure when the throttle is opened quickly (so that you have better acceleration).

[99yam40]

Well if the OP was using compressed air above 10 psi and not his mouth to blow thru, it would let air thru.
He did not say, so it could be either way I guess.

also where did you get the term accelerator line, I have not seen that in a Yamaha manual or parts break down, but that does not mean you did not see it somewhere

[pstephens46]

Whatever happened to testing a “failing” motor? What would Rodbolt write here? Where are all the questions for the OP? What an incredible waste of time as Rejesturd vomits forth whatever the F50 service manual states. Absurd....

[panasonic]

Today 10/20/19 I went through the fuel system. From the gas tank cap on. When I got to the fuel pressure regulator valve, part # 9 on the vapor canister blowup view, it is mounted on top of the vapor canister, it has a #1200-13F40 on it. I discovered it was open, I could blow air through the in side and it would pass through. I thought that it should be closed when no vacuum is present. I spread some WD40 in the or-faces and used compressed air to free it up. The motor started. I might be on to something. Rain is holding me up for now. A friend has a fuel pressure gauge. My next step will be running it With the gauge attached. Has anyone else had a problem with the fuel pressure regulator valve?
Thanks again

You say it shuts down instantly "like turning off the key" To me that sounds like a lost of ignition....not fuel.

I would proceed with checking the fuel rail pressure with your friends gage, now that the engine starts again.... just to rule that out. Then move on from there.

Do you have the proper service manual for your engine?

[rejesterd]

Well if the OP was using compressed air above 10 psi and not his mouth to blow thru, it would let air thru.
He did not say, so it could be either way I guess.

also where did you get the term accelerator line, I have not seen that in a Yamaha manual or parts break down, but that does not mean you did not see it somewhere

I don't know what Yamaha's term for it is, but that's what that line is for: acceleration.. it ensures that fuel flow can increase along with the increase in air when you quickly open the throttle.

[99yam40]

Just saying making up names of parts will confuse people,
especially new people to motors and then they start looking for the part you made up