plugs fouling

[maxpayne@netscape.com]

I have 2003 f200txrb yamaha engines and i noticed on three cylds on same side my spark plugs
are turning black. facing flywheel left bank. did not notice any misfiring? but think this could lead to other problems right bank plugs seam normal light tan color. any body have same symptom

 

[isla]

Re: plugs fouling

I think it is not a big problem, it is possible that the throttle body left is regulated differently from normal, I do not think any problem injectors and valves.
For the motor, counsel to do so by mechanical professional inspect only yamaha
imho

 

[rodbolt]

Re: plugs fouling

ALWAYS refer to the engine as port or stbd, just like the rest of the boat.
it tends to lessen confusion .
if the are a dry sooty black its going to indicate a rich fuel mix. most likly caused by improper linkage adjustment as the ISC supplies idle air to all 6 cyl from a common passage.
first place to start is by checking the linkage with a tech mate or equivalent manometer.

 

[maxpayne@netscape.com]

Re: plugs fouling

thanks your right it was the starboard side head.and last summer had recall done on throttle linkage on both engines by the dealer. did not notice problem
before repair done.again thanks for the insite.