40hp 4 stroke tiller steer problem valve

[Bennylear]

Howdy, new to the forum, just put in my Yamaha 40hp tiller steer 2011 model to get serviced and also get the idle fixed, it won't idle and dies if no throttle on startup, dealer said he needs to replace some valve and the valve cost 900 bucks to supply and fit a new one, has anyone had this problem and does it sound right, also the motor has only done 300 hours, doesn't seem right to me any ideas suggestions cheers

[rodbolt17]

you need to find a dealership with trained techs.
yes the ISC valve can fail.
it is simple to test.

[Bennylear]

you need to find a dealership with trained techs.
yes the ISC valve can fail.
it is simple to test.

Cheers for the reply, they are trained, what is the ISC valve where is it on the outboard and what does it do ect

[rodbolt17]

it controls idle air at idle.
at speed it simply opens to 100%.
at idle it closes a bit to control idle air.
if it fails open it idles fast.
if it fails shut it may not idle.
can be tested.
the ECU does not monitor it.
if it fails open you may get an intake air code.

not difficult to test.

[boscoe99]

The F40LA/LEHA model (if this is what you have) contains a throttle body that has an integrated throttle position sensor, MAP sensor, air temperature sensor and idle speed control valve. Best guess is that this is what your dealer is talking about.

This website sells the part for $464 and change. Not difficult to replace yourself if you are so inclined. As rodbolt suggests, get a second opinion from another dealer mechanic to verify that the throttle body is definitely what you need. You can then negotiate with the dealer to get a better price, do the work yourself, or find an independent mechanic to do it for you.

I am guessing here but can't see more than an hours labour to R and R that part.

6BG-13750-00-00 THROTTLE BODY ASSY

[rodbolt17]

an hour and your milking it.

[Bennylear]

What's the problem from will it do it again ?

[boscoe99]

What's the problem from will it do it again ?

Where is flight MH370?

[Bennylear]

The only thing I can put it down to is shit fuel, or not enough use, dunno.

[boscoe99]

We all would like to know the root cause of a problem. Sometimes it is impossible to find. Sometimes stuff just ups and dies for no real reason at all.

Let 10 engineers examine a defect and you might come up with 11 causes for such defect.

The aviation industry spends millions and millions of dollars trying to find the cause of a problem. Sometimes they find it. Most times they simply close out their investigation with a "probable" cause. "probable" meaning it is their best guess. No one really knows for sure.

I suspect that if you replace whatever is broken then it won't fail again in your lifetime. But certainly using the motor often and supplying it with clean fresh gasoline will help to prevent any future problems. Related to the part or other items on the motor.

Good luck.

[rodbolt17]

as the valve never touchs fuel I would most likely rule out gas.
moisture on the otherhand can cause the rotor shaft to bind.
I have cleaned a few with combustion chamber cleaner.

[Bennylear]

Is it a component that fails in allot of yamahas, pity it is the whole bloody unit in the tiller steer not just one component, I'll let you guys know the outcome when I get the motor back cheers once again for the helpful info