How to clean IAC of 4-stroke Yamaha Outboard

[pstephens46]

How does the IAC get hot.

I have a Yamaha F60 outboard that is very difficult and sometimes impossible to start after only 10 minutes of half throttle running.

Leave it 10 minutes and no problem.

IAC does get much warmer than the surrounding intake. It moves to adjust idle rpm. I don't know what the threshold of too hot might be for that motor. That would be an indication of an issue with IAC.

Hard starts after running may be the rich fuel/air mixture situation. By waiting 10 minutes I am betting this is enough time for the vapor to exit the intake. The engine will start normally then. My F150 does this.

Next time try opening the throttle slightly using the neutral button on your control. Hopefully you are aware of how this works. This lets in more air to intake. Then try cranking once or twice. Close throttle back to idle and try again.
This process works for me. If this doesn't work, more troubleshooting

And you are still boating in CA in November?

[boscoe99]

Where the hell is fairdeal?

We need the current flow to the IAC to be measured. Knowing the amount of current can indirectly tell us if it runs on the hot side or not.

Maybe measure your IAC with a temperature gun as the motor idles and let us know the highest temperature reading that you see.

My next Yamaha will be a model that does not use an IAC valve.

[pstephens46]

Where the hell is fairdeal?

We need the current flow to the IAC to be measured. Knowing the amount of current can indirectly tell us if it runs on the hot side or not.

Maybe measure your IAC with a temperature gun as the motor idles and let us know the highest temperature reading that you see.

My next Yamaha will be a model that does not use an IAC valve.

Then you will have the actuator that will fail and cost $2441.00

[fairdeal]

I will check my post history - thought I did some work with measuring the power operating the F225 ISC.

Although "muddying the water" is that, I believe, it operates with "pulses" - not continuous DC.

Boscoe posted an interesting link where a guy explained how to "manually" operate it with a 12V AC source and a capacitor.

I tried it - and it works. I assume the capacitor shifts the "phasing" (perhaps not the right word) between the two windings to make the rotor move.

[boscoe99]

Then you will have the actuator that will fail and cost $2441.00

Nope. Don't want one of these either.

[bbakernbay]

I will check my post history - thought I did some work with measuring the power operating the F225 ISC.

Although "muddying the water" is that, I believe, it operates with "pulses" - not continuous DC.

Boscoe posted an interesting link where a guy explained how to "manually" operate it with a 12V AC source and a capacitor.

I tried it - and it works. I assume the capacitor shifts the "phasing" (perhaps not the right word) between the two windings to make the rotor move.

Were you successful in cleaning your ISC using carb or combustion chamber cleaner as suggested by rodbolt? What was cost of your replacement? Yamaha wants10X cost of regular ISC's. Do you have link to operating it manually?

[fairdeal]

Were you successful in cleaning your ISC using carb or combustion chamber cleaner as suggested by rodbolt? What was cost of your replacement? Yamaha wants10X cost of regular ISC's. Do you have link to operating it manually?

I've been fortunate, neither the ISC on my F225 nor the one on the F90 (in the photo above) have needed to be cleaned - or replaced.

Many posts here and elsewhere have suggested that with free access to rummage through the valves at a "foreign auto parts" store, one would eventually turn up a match for Yamaha

The easiest way to operate the valve manually is with the YDIS software.

Otherwise, as stated above, simply determine which are the coil winding contact pairs -
there are two or three coils, depending on model.
Then power each coil with ~12V ac, using an inline capacitor on one pair to shift its phase from the others.

[bbakernbay]

I have the YDS software so will try that once the winter is over.

I would still like to clean the pintle portion using cleaner and air as recommended by rodbolt.

I just bought a used one on eBay for $56 and bought a can of Idle Air Control Cleaner so want to clean it up before I swap it out.

Prefer to do that at the home workshop first but don't understand the electronics of using 12V AC and the inline capacitor.

Would welcome further advice on the components used. Thanks.

[bbakernbay]

Finally Some Good News

Well we have opened the cottage and the Yamaha F60 is back in the water and it looks after 3 weeks usage that the major problem is starting to disappear.

Late last season I started using the Yamaha Ring Free Plus in the fuel tank and continued again this season. I double the recommended dosage.

I have made at least 10 return trips to the Marina dock which requires some very low speed which resulted in frequent high rev situations last season. This year has been very good so far, only once did the problem return and I just turned off the ignition and immediately turned the key on again and the problem was gone.

It still will not continue to run after the first turn of the key on a cold start but always runs perfectly on the second turn. I can easily live with this minor issue.

I just bought a 12 pack of the small 3 oz bottles of Ring Free Plus and I plan to give it the heavy dose at end of season to de-carbonized the engine prior to an oil change.

I still have the used IAC/ISC valve as a backup.

Any thoughts by others would be appreciated.

[bbakernbay]

IAC does get much warmer than the surrounding intake. It moves to adjust idle rpm. I don't know what the threshold of too hot might be for that motor. That would be an indication of an issue with IAC.

Hard starts after running may be the rich fuel/air mixture situation. By waiting 10 minutes I am betting this is enough time for the vapor to exit the intake. The engine will start normally then. My F150 does this.

Next time try opening the throttle slightly using the neutral button on your control. Hopefully you are aware of how this works. This lets in more air to intake. Then try cranking once or twice. Close throttle back to idle and try again.
This process works for me. If this doesn't work, more troubleshooting

And you are still boating in CA in November?

How do you access the Idle Speed Control Valve. It is not easily visible, I have the Service Manual and it looks like it is located behind the Intake Manifold.

[TownsendsFJR1300]

How do you access the Idle Speed Control Valve. It is not easily visible, I have the Service Manual and it looks like it is located behind the Intake Manifold.

A year, HP and model # would help....

[bbakernbay]

A year, HP and model # would help....

2009 Yamaha F60LRH 104DBDCF-9BD4-436A-B27A-77586C84C1EE.jpegA7F9107B-86AA-4EA6-B1EF-517F782275F3.jpeg

[bbakernbay]

1E9C0713-AC56-4277-B4A2-176C40DDCE4D.jpeg Here is the 2009 Yamaha F60 - How do I access Idle Speed Control Valve?

[TownsendsFJR1300]

Looks like you got it out..


.

[bbakernbay]

Looks like you got it out..


.

No I didn’t get it removed. Based on the Service Manual it appears that the IAC is located behind the Intake Manifold and I am looking for some advice on what is needed to access IAC. I am a bit reluctant to start removing the intake manifold if it involves having to replace gaskets, etc.

Has anyone replaced their IAC?