Probably something wrong inside the governor of my 3GM30FC

[trikola]

Hello everybody!

This is my first post here - but I've been around reading for a year or so. I'm located in southern Norway and sail a 1997 X-Yacht X332.

I'm currently concerned that the engine - Yanmar 3GM30FC - has a problem - can't check it out easily because the boat is still winterized on dry land, so starting is not an option without rigging cooling water. I performed a search here on the forum but did not succeed.

What happened about 2 weeks ago is that I drew the engine stop wire (in connection with fitting a new engine control panel) and realized that it did not come out as far as before. This was of cause not the case when hauling out in october - so something had happend while the engine wasn't in use. It pointed out that the stop lever at the engine would not pivot far enough. I turned the crankshaft a bit but it did not make any difference. I am now afraid that I will not be able to stop the engine (if it even could be started).

I had another effect last summer which possibly is connected to this: Coming back into the marina and going into neutral made the engine stop. I found out that the idle RPM from now on was considerably lower. It wasn't a fuel issue and in the end I just turned the idle adjustment screw one turn and life went on - no problem.

Until this engine stop lever issue comes up. Anybody any idea what this could be?

Thanks in advance.

Andreas

[roverhi]

Facing the engine from the front, the engine stop device is on the left hand side about midway down the forward side of the engine. It's a lever attached to a shaft that runs into the engine, probably the high pressure injection pump. Don't have the engine in front of me to verify. It should have the end of the cable from the shut off pull knob from the cockpit or wherever attached. Once located see if you can rotate the stop control by hand, may need to disconnect or loosen the cable clamp to do this. The stop cable has a habit of freezing up from corrosion and may need to be replaced.

If you can't rotate the stop mechanism, it may be frozen by corrosion. Have seen this happen. Spray liberally with penetrating oil and GENTLY tap on the shaft and try to rotate it by hand. It should come free and rotate with light pressure to shut off the engine.

If you cannot get the shutoff on the engine to rotate you'll have to block off air to the engine to stop it or otherwise shut off the fuel. If you go with the former, don't use your hand to cover the air intact. Remove the air filter and find a piece of wood or something to block the air intake. A stiff piece of canvas might work but wouldn't use any light fabric. DON"T USE YOUR HAND. Don't know the suction power of a diesel but wouldn't want to find out the hard way.

[sailorchic34]

The fuel cutoff is not connected to the governor. It simply cuts off the fuel supply at the injector pump. Probably a stiff cable or a cable with a broken strand. You should still be able to move the fuel cut off lever on the front left side of the engine by hand. You can also open the decompression levers on the top of the engine to stop it.

[trikola]

Thanks so far.

Good to know some alternatives to stop the engine in case I get her on the water without a solution of the problem.

I attach a picture. The brown tubing is the stop wire to the engine stop lever. The wire is NOT blocked - it is the lever which no longer covers the same pivoting angle as before. If I push the lever the wire flexes until the lever comes to its stop.

Right above the lever is the idle rpm adjustment screw which I had to use last summer. According to my copy of the Yanmar shop manual (which btw explicitely states that it does NOT cover the "FC" version of the engine) there must be some mechanical cooperation between these two elements: stop lever and rpm adjustment.

Is it easy to remove the cover for inspection and reinstall it again in working condition? The manual appears to describe some different details compared to my engine.

Thanks again.

[roverhi]

The shut off lever may not be going full swing. My 2GM had it's shut off frozen and wouldn't function at all. If the valve or whatever that the lever controls is partially frozen it may be restricting the idle fuel. Might want to operate that lever full swing a number of times and spray with penetrating oil to free up whatever is at the end of that shaft.

[trikola]

Just to close this issue: The defect disappeared as it came: suddenly everything was fine again.

Thank you for your attention and help.

[boatpoker]

it didn't disappear ..... its' laying in wait.