2005 F150 help and advice

[TellMeWhen]

Hello all I just purchased a boat with this motor. It has just under 100 hours and sat covered mostly unused by an older gentlemen. The marina helping me is draining the tank, changing fluids and otherwise doing a full service on the motor. Everything I was told was that these were "bullet proof" so I had no concerns other than making sure the fuel system is good to go after the long sit. Then, a friend referred me to here and to research the balancer issue. I had no idea about this. I asked the marina to look into it and change the balancers out while doing the motor service. They looked at me kind of funny but said no problem they would look into it. Is there anything else I should be concerned about with this model and year? I thought I really hit a home run on a low hour bullet proof motor, but now that I read about the balancer issue and even some deal with a vapor lock kit (which I still don't understand) I am a bit concerned. I can't turn back from the sale now unless a problem arises, so I just want to make sure I cover my bases. I would appreciate anyone's input on this and thank in advance!!

[rodbolt17]

have the balancer done as well as a complete fuel system service to include cleaning the injectors and VST.
then have the cooling system serviced to include a minimum of the water pump.
then go play
if you have a stalling issue when slowly moving the throttle below about 1200 RPM that's an easy fix.

other than the balancer,that motor was pretty much bullet proof.
however with that much sitting cooling and fuel systems degrade to the point that WOT running can cause catastrophic failures.

balancer is less than 400 bucks and takes all of 45 min to replace.

[boscoe99]

I would add that it is very important IMO (in addition to all that you are already having done) to have that particular model propped correctly. With the boat loaded as you would usually use it, make a wide open throttle run or two. Select and use a propeller that has a pitch that will allow the WOT RPM to be at or near 6000.

The balancer is a very well known issue. It uses a composite gear that can fail and in so doing block oil passageways, leading to oil starvation which can damage the engine severely. Yamaha is now on their fifth design for this part. Let's hope they have finally gotten it to be a durable and reliable as it was intended to be.

$336 and some change at this website. Hopefully your dealer will price match.

Item 26 in this illustration
2006 and Later F150XA Yamaha Outboard CYLINDER CRANKCASE 1 Diagram and Parts

The fuel issue is not a vapor lock issue as that term was used with carbureted engines. It is rather a matter of excessive fuel vapors (overly rich fuel mixture) causing the motor to be hard to start after it has sat for a short period of time after being used. If you have an F150T(X/L)R D model then it might be prone to this issue. Might not be as well. Many never see this problem. At a particular point in production Yamaha implemented a system to capture the fuel vapors so they do not present a problem.

[rodbolt17]

hey zues Christ.
someone actually knows the difference of vapor lock and a simple over rich issue.

efi cannot vapor lock.


they can run a fever.

[TownsendsFJR1300]

I believe the balancer is free thru Yamaha (installed as well).

As noted, it was an known issue which Yamaha seems to be trying to make good.

Mine was replaced under warranty, no cost. Takes about 45 minutes..

Re the vapors, never had an problem (hot or cold) but did have the low idle issue(dip to 600, occassional stall in gear). Eventually got it repaired correctly, 700 RPM's once warm, NO more stalls...

If used in salt water, its strongly recommended to flush with fresh water. After your fuel system is serviced, Yamaha's "Ring Feee" is an excellent fuel aditive to keep your fuel system and top end super clean, highly recommended...A fuel stabilizer is also mandatory unless run very often...

[TellMeWhen]

Thank you gentlemen for your input - I really appreciate it. What is this low idle / stalling issue that you guys are referring to?? Is that also an issue with this model that I need to have looked at / fixed? I am totally unaware of that issue altogether.

[boscoe99]

You mentioned a "vapor lock" issue in your first post. It is not really a vapor lock issue. The misinformed have used that term, incorrectly, so often and so long, that folks believe that is what is happening. Ain't so.

What appears to be happening is that excess fuel vapor is either causing an idling motor to stall or a hot motor, that has sat for a short while, to be hard to start. In essence, the motor is flooded.

The fuel vapor issue affected a relatively fuel number of your specific models. It is quite likely that you won't have the problem. If you do, then you can either add the kit that Yamaha offers or you can find and fix the specific problem that is causing your particular model to suffer.

The engine gets hot. The fuel system gets hot. Fuel boils. Vapors from the boiling fuel get into the air intake system. System is overly rich. Won't run or start. It is not the supply of fuel being disrupted due to too many fuel vapors. It is too much vapor getting into the intake system.

[TellMeWhen]

ok, got it. Thanks for your help. I'm an idiot at this stuff. The complete service is being done and the balancers replaced, and assurances from the Yamaha tech that all is well. This "overly rich" issue sounds like something that is hit or miss depending on model, and I'm just guessing - probably intermittent even on a motor with the problem. So unless it acts up on my sea trial, I assume I probably won't discover whether this issue exits until sometime after I own it. No one here seems to be sounding the alarm that it's an expensive fix, so I guess I'll roll the dice on that one and pray I'm getting a solid motor. Thanks again for everyone's input and advice.