Yanmar 2GM20F - Bag of Nails

[Stoshak]

My new boat has a Yanmar 2GM20F, and when idling it makes a loud tappety rattly sound. This disappears as speed increases and is absent at cruising speed. I've adjusted the tappet clearance to manual limit, .008 in, and it made no difference.
Is the noise inherent in the model, or have I got a problem?

 

[savageseadog]

It might be mis-timed you get more clatter if the injection is too far advanced. Only other things are clogged oil filter, wrong oil or some sort of oil circulation problem

 

[Bilgediver]

Sounds a perfect description of a cold idling Yanmar ..... and if on flexible mounts it looks like it is trying to escape from belw decks /forums/images/graemlins/laugh.gif

Yes it should go when you rev up and surely once the engine is warm it doesnt return at idle though the engine might be a little noisy.

Don t be tempted to set the tappets too tight cos it isn t these.

 

[col_shaun]

i have had the same problem as well it looks like some one from coldits trying to clime the wall as is the best description i can give but mine has stood for 4 years so things will need looking at so far iv striped doun the water pipe work as there was a limited amount of water coming out of the tail pipe, solt had blocked it up. then i found loud loud bangs and knocks so i traked it doun to the prop as the engine was chuking it self about so much that the only thing i could think of was to pump more grease in the gland that worked, less noise, try that it may work for you i put in almost 1/4 of a tub to stop that as the old grease was hardend over time.

 

[TheBoatman]

Last winter I changed from a 2GM20F to the new 3YM20 and your description of the 20 ticking over is spot on. I truly don't believe that anyone could design an engine that shook and rattled as much as a Yammy 20 but at the same time went silent and ran perfectly as soon as you give a little throttle. I used to liken mine to River dance because I reckon that if I could have fitted dancing shoes to the engine mounts I'd have a pretty good impression of all that jumping up and down whilst stomping wooden clogs on a stage.
I always got the impression that it was trying to escape ~ but it gave me years of unstinting service.

AND before you ask the only reason I upgraded it to the new YM20 was because the diesel return pipe fractured and poured neat diesel into the air intake and blew it up ~ the cost of repair didn't warrant it against a new YM.

BTW the new YM is a fantastic little engine!

Peter.

 

[davidbains]

Stoshak it might help if you increase the idling speed.
Boatman, I'm very interested to hear you're pleased with your upgrade cos I'm planning the same myself. Have you noticed a slight increase in power? Does the three cylinder model run quieter, dance around less?