2009 Yamaha F60 4 Stroke Idle Air Control (IAC) Valve

[bbakernbay]

It has been suggested elsewhere that the below noted problems are possibly caused by a sticking IAC Valve on my Yamaha F60 4 stroke outboard.

Any opinions here on that recommendation?

Is it fairly straightforward to remove the IAC Valve and presumably spray it with carb cleaner or throttle body cleaner?


We bought a 5 year old 820 SunChaser Pontoon Boat with an F60 4 stroke outboard this past summer. Very few hours, less than 90 now.

I cleaned out fuel tank, drained water separator and ran Yamaha Ring Free and Stabil thereafter.

Engine runs quiet and smoothly except for 3 issues, 2 of which are minor, the 3rd is annoying.

1. On cold start, engine starts immediately on first turn of ignition key but then dies as it seems it is not getting fuel. Turn key 2nd time and fires up the way it should but never does on first key turn. I can live with this.

2. On cold start, frequently the engine starts to rev up abnormally, sometimes it returns to normal idle but most times it doesn't and I turn it off and restart and everything is fine, normal idle rpm. I can live with this but not happy about it.

3. After cold start and running 10 minutes to Marina if I turn off engine it is extremely difficult, almost impossible to get it re-fired. My practice is now to leave it idling when I am loading or unloading passengers or shopping.
The same issue if I take grandkids fishing and we anchor then when they want to change locations, I can barely get it started. Battery is 100%.

I really get frustrated with the 3rd problem, especially on an engine with less than 100 hours.

I purchased the Yamaha Diagnostic Software and cables on eBay and it is amazing but unfortunately there are no Error Codes showing, even when I do cold start and rpms go a bit crazy.

The guy who owns the Marina and looks after 120 boat engines can't find the problem.

 

[99yam40]

check to make sure water is flowing thru the fuel cooler while motor is running

Do you ever pump the primer bulb to make sure everything is primed and full of fuel before starting for the 1st time of the day?

 

[bbakernbay]

check to make sure water is flowing thru the fuel cooler while motor is running

Do you ever pump the primer bulb to make sure everything is primed and full of fuel before starting for the 1st time of the day?

No, I never check the fuel tank bulb unless it has been a week or more between starts or in the situation like Issue 3 where it is nearly impossible to start after only a 10 minute run at half throttle.

Some people suggest that the engine should be run at full throttle on a regular basis, is that correct. With the pontoon boat I rarely do that.

If the water is pissing out strongly from the discharge into the water does that necessarily mean that the water is flowing through the fuel cooler jacket?

Thank you for your assistance.

 

[99yam40]

nope , has to be checked to see if there is proper flow thru the fuel cooler.
pull a hose off of it and start the motor to see if it has flow in the correct dirrection.

check primer to see if it helps during cold starts 1st thing of the day,'if it does then you can try to find out why.

Slow trolling can cause fuel to dilute the oil in 4 strokes.
if you are not having a problem with that do not worry about it

 

[bbakernbay]

Thank you 99yam40.

It is in storage for the winter but I can easily check the fuel cooler water flow as you suggest.

 

[99yam40]

something I read about once was the line that heads back to the bottom of power head / exhaust area stopped up not letting water to flow even thou the cooler was not stopped up

 

[Capt Ken]

If the fuel cooler's water line plugs, the pee stream gets very strong. Then you get vapor lock but that takes a bit to happen. Sounds like the idle air control is not operating smoothly. Get ready to buy one. No cleaning or lubing it. Even though the diagnostics don't show a fault doesn't mean there's no problem. Many faults don't throw fault codes. You have to know how to read the numbers.