F300xca losing power after 100 hour service

[JimBen14]

My 2013 F300xca Yamaha with 500 hours was running fine until I had the marina mechanic provide a 100 hour service. He changed the oil, gear oil and plugs. The stern bilge fuel filter/water separator was also replaced. On the first day out, the engine lost power 3 times on a 2 hour run. While on plain between 2500-3500 rpm's the engine looses power for a brief moment. It is enough to feel a slight jar of the boat. The mechanic said he will look at the motor fuel filter as he feels I may have a slight clog.

Any advice is greatly appreciated.

[TownsendsFJR1300]

Might check part #11, make sure that seal is in place:

https://www.boats.net/catalog/yamaha...ca-0113/fuel-1


.

[JimBen14]

Stumped! Tech completed 100 service on F300XCA at 500 hours including replacing the following: primary fuel filter, VST filter, and MAR fuel filter. Used 11 hours and purchased 40 gallons of fuel. Next trip the outboard loses power beyond 2000 rpms. At the dock while in neutral, engine raced to 3800 rpms with no issues. What could be causing the outboard to bog down and stall while moving? Any comments are welcome. Thanks in advance.

[gunz@pc]

I agree with Mr. TownsendFJR1300. That little "O" can cause some problems if left out and sitting in your pan somewhere.

[99yam40]

or has a bad spot on the o ring or the surfaces it seals to.

running a motor with no load does not use much fuel, loaded it probably cannot keep up with the use if there is a air leak on the suction side of the lift pump

[TownsendsFJR1300]

Revving to 3,800 with no load is not the brightest thing to do...

I'd be finding another tech as something he did, wasn't done correctly (as the issue arose RIGHT AFTER his service).



Or ask for another tech to check his work.. Something obviously isn't right...


..

[JimBen14]

Thanks for the info.. If there was an air leak, I would assume the fuel to air mix would be incorrect and that a warning light would show up? Could it be a sensor?

[TownsendsFJR1300]

Thanks for the info.. If there was an air leak, I would assume the fuel to air mix would be incorrect and that a warning light would show up? Could it be a sensor?

A bad air leak would usually cause the engine to race mostly, and not idle down- There's no warning light for either.

You never said anything about any engine problem codes popping up. Did the tech hook up a Yamaha YDIS to check the engines parameters, anything unusual?

The primary, on engine, fuel filter assembly "O-ring" is what I referred to earlier. I don't know if he changed the filter the first time or... That cup tends to turn yellow over time and EXPAND ever so slightly.. When you try ro re-install it, it feels light it's tight(and seated) when it actually is NOT. I've personally had this occur on my F150..


**Per post #1, quote: "He changed the oil, gear oil and plugs. The stern bilge fuel filter/water separator was also replaced" End quote. I assume the stern bilge fuel water separator
is NOT the engine mounted filter, correct?

If so, I would be checking that unit (that the filter screws on to) for any corrosion, double o-rings (by accident) etc. This includes a separate see thru (if equipped) water collector on the bottom (see below pic). You could very well be sucking air thru that filter mount/assembly



Someone needs to go over and check EVERYTHING HE DID.. It ran good till he touched it, 500 hours worth of running good...




.

[JimBen14]

He did change the on engine filter the second time he came. The filters he changed were: primary fuel filter, VST filter, and MAR fuel filter. I am having a tech hook up a Yamaha YDIS to check the engine. There were no codes, alerts or warnings when this happened. If there was water in the gas, I would have expected an alert. Should I add a fuel additive?

[fairdeal]

Thanks for the info.. If there was an air leak, I would assume the fuel to air mix would be incorrect and that a warning light would show up?

No.
The engine has its own tiny fuel tank, the VST
that's what the fuel injection system runs off.

In addition there is a 'low pressure' system that sucks gas from the boat tank
to keep that VST full.

A leak on the suction side of the low pressure system
would let the VST 'run out of gas'
but that wouldn't change the stoichiometry
and the engine ECM wouldn't know what was happening.

Do you have a primer bulb in the fuel line?
by squeezing the primer bulb while running,
you should be able to keep the VST full.
(you can feel the the bulb is unable to pump any more)

If the primer bulb can't move full properly,
that points you to a problem between the primer and boat tank.

If the engine runs fine so long as you use the bulb to fill the VST,
that points to a problem between the bulb and the engine.

[99yam40]

My 2013 F300xca Yamaha with 500 hours was running fine until I had the marina mechanic provide a 100 hour service. He changed the oil, gear oil and plugs. The stern bilge fuel filter/water separator was also replaced. On the first day out, the engine lost power 3 times on a 2 hour run. While on plain between 2500-3500 rpm's the engine looses power for a brief moment. It is enough to feel a slight jar of the boat. The mechanic said he will look at the motor fuel filter as he feels I may have a slight clog.

Any advice is greatly appreciated.

Stumped! Tech completed 100 service on F300XCA at 500 hours including replacing the following: primary fuel filter, VST filter, and MAR fuel filter. Used 11 hours and purchased 40 gallons of fuel. Next trip the outboard loses power beyond 2000 rpms. At the dock while in neutral, engine raced to 3800 rpms with no issues. What could be causing the outboard to bog down and stall while moving? Any comments are welcome. Thanks in advance.

what you have written does not sound like it is the same thing that happened.

does it loose power for a second and feels like a slight jar of the boat ?
or does it bog down and stall while moving?

[JimBen14]

I am planning on checking the bulb for a test soon to see if it is full or runs while I prime it. I believe it was the same thing in that the engine would just lose power/rpm's without touching the throttle.

My daughter videoed the instruments and I was run at 3200 rpms on plane and the engine suddenly dropped to 1900 with a jar. At that point I could not get the rpms over 2400. As I tried to increase throttle and it did bog down stalling at least 2x. I did try to wide open the throttle and it would not go over 2200. Earlier that day I was able to easily run at 3900 at 35mph and burning 12 gal with 3 people and 100 gal of fuel. I would assume that is normal for this boat? I know I pushed it up to 45 mph and it seemed to run fine. Hopefully, I can get a computer read out in the next few days.

[JimBen14]

As I expected, the computer read out did not indicate any issues. Since the warning and alerts have not been on, I was not surprised. Tech now wants to run the boat in the water to see what is happening. I have a feeling it is the fuel pump. Thoughts?

[JimBen14]

While at the yard today, I started the engine and did get a low oil pressure error. I checked the oil level and it was at 85% or so. I then ran the engine up to 2500rpm's and it cut back to 1900. I have read it could be a faulty oil filter, sensor or pump. Any advice is appreciated.

[JimBen14]

Found out this was not an error, but that someone had pushed the mode button. Back to square one and thinking it may be a fuel restriction in the system. Possibly a fuel pump?