Yanmar 2GM20 Vibration Problem

[Cunuvar]

Hello ,

i hope someone can advise about my problem.

I have a Yanmar 2GM20 on Tacar Boat 6.60 since i got the boat 3 years ago, It is almost 15 years old. My engine problem is about vibration. I changed engine mounts one month ago, We made carefull line adjustment. But my engine vibration problem is not solved completly.

Please check my video.

As you see on this video , there are highly vibration some rpm. It scare of me .

Do you have any idea about the problem ?

Thank you for your advise.

Best Regards
Cenk

 

[RichardS]

Presumably the video is shot with the engine in neutral so the alignment issue can be ignored? If it is not in neutral, what does the vibration look like when it is in neutral?

These engines do wobble quite a bit at idle speeds so I don't think there is anything terrible going on. Perhaps try adding some good quality injector cleaner to the fuel and see if that improves things.

It seems to smooth out at higher revs, as you would expect.

Richard

 

[Daverw]

Looks about the same as ours does, as I expected for a two cylinder. as others said, it settles down a lot under power.

 

[Cunuvar]

Presumably the video is shot with the engine in neutral so the alignment issue can be ignored? If it is not in neutral, what does the vibration look like when it is in neutral?

These engines do wobble quite a bit at idle speeds so I don't think there is anything terrible going on. Perhaps try adding some good quality injector cleaner to the fuel and see if that improves things.

It seems to smooth out at higher revs, as you would expect.

Richard

Thank you for your reply.

The engine was in neutral.I just want to show, vibration is rising instantly at some rpm.

I know that, my engine is 2 cylinder , and not stably like 3 or 4 cylinders .But i think it is not normal . It did not wobble last years.

You are right about rv. Espiecially , it is very stably 2500 rpm or 1900 rpm or 1100 rpm.

I believe that , the problem is about injection , because so much fuel is coming back to fuel tank from injection.

How can i clean the injection ?

 

[Cunuvar]

Looks about the same as ours does, as I expected for a two cylinder. as others said, it settles down a lot under power.

Yeah you are right, but i dont believe , the guilty is two cylinder

 

[Channel Sailor]

Looks normal to me. Tick over looks normal, as does the mid speed increase in vibes that stabilises above 2500.

 

[michael_w]

I'd say its idle speed is too low. What does the manual say?

 

[Channel Sailor]

I vaguely recall the idle speed in the manual says is 800 or 850, so maybe it is too fast ( if counter is accurate). However I think mine is set very slightly fast because it reduces the rattles from the galley.

 

[RichardS]

I believe that , the problem is about injection , because so much fuel is coming back to fuel tank from injection.

How can i clean the injection ?

Don't worry about the diesel return to the tank. Different engines return a different amount of fuel and some return half the fuel, so that doesn't tell you anything.

Try some diesel injector cleaner. It's a liquid which you add to your fuel tank and then run the engines. After a few hours it might improve the running at low revs. I don't know what brands of injector cleaner are available in your market but I would expect to pay something like 10 - 15 Euro for a single-treatment bottle. You can get cheaper versions but, as a generalisation, I'm not sure that the cheap ones are so effective.

You can remove the injectors if you have the experience and the tools, and clean them, or have them professionally cleaned and tested, out of the engine. However, I would try the additive first and see if it makes an improvement.

Richard

 

[peteK]

Looks ok to me, the only time I had irregular tickover was when I had water in the fuel.