Yanmar 3HM35F question/problem

[KTP]

We have a new to us 1989 PS34 powered by a Yanmar 3HM35F (same year) with about 2600 hours on it.

It seems to run fine, powering the sailboat at 6.5 knots at 2400 RPM.

I really started digging into it today to change the oil in the engine and clutch and noticed one of the injectors and the area of the engine around the injector is extremely rusty compared to the other two injectors. This makes me wonder if there is some issue there causing that or if it could be normal. The worry part of me wonders if that cylinder is getting an improper fuel supply causing it to overheat and corrode.

I have attached a pic which shows the injectors.

[Sailmonkey]

Id be more inclined to look for drips from the cockpit hatch before digging into the engine.

[Wotname]

I agree with Sailmonkey, its looks like external water has been (or still is) dripping onto the third cylinder area, especially as the third valve cover bolt is also more corroded than the other two.

or

perhaps that injector (only) was previously removed for whatever reason and suffered paint damage in it's removal which was never repainted.

Maybe it's just me, but I hate rust areas on an engine so I would clean it up and repaint where I could. I also hate dirty oily engines but at least they don't rust as much .

[NYSail]

Great engine..... had on my last boat. I would consider pulling the injector and cleaning the area.... plug the hole so no debris gets in engine of course. But of everything is running well and you’re not up to it I bet all is fine and this was just a result of water spillage. Keep an eye on it to see Amy changes.
You would know if injectors were not getting proper fuel.

Greg