Yanmar 2GM Questions

[mikecontessa26]

Hi, i'm in the process of buying a Contessa 32 with a 1990 Yanmar 2GM engine in, I checked over the engine personally but my experience is limited to a 1GM (not to dissimilar)

The Injectors were replaced last year and I understand this is a big expense, we started the engine on the hard (with a bucket of water) and it started first time after 6 months without use and ran for 5 minutes and idled well.

However, when starting the engine the owner used full revs initially and said the engine would not start without doing this, is this normal? The engine has done 1500 hours with my 1GM it starts first time while in neutral.

Do you think it's reasonable to ask the owner to get a mechanic to do a compression test? I would pay the bill if necessary, does the compression test show up most things?

A surveyor has said that as the engine has done 1500 hours he would like it removed and the head off, the owner thinks this is extreme as the engine uses no oil all season and runs fine. I really respect the vendor and his honesty in other areas so have no reason to doubt him.

Any advice as always much appreciated

Thanks

Mike

 

[Spyro]

I believe the handook says full throttle when starting the engine, Mine usually requires this but as soon as it fires I throttle back to a fast idle. I would be more concerned about the exhaust elbow as they are known to fail. If it's a 1990 I would think it will be needing replaced if it's not already been done. Also If it's a 1990 engine it will be a 2GM20 not a 2GM that is a different engine. Taking the head of and all expense associated adds a lot to the price of a survey if you then decide against it. Getting the boat in the water for a sea trial might be money better spent.

 

[mikecontessa26]

The owner did mention the handbook said full throttle was needed, the engine is about 15hp I think so yes the discontinued 2GM engine. I'll ask about the exhaust elbow and see if I can get replacement included in the price if it's not been done.

The owner is sailing the boat from Pisa to Brindisi and i'm joining for part of the journey so should get a long sea trial which will be good.

Thanks

 

[bendyone]

The owner is sailing the boat from Pisa to Brindisi and i'm joining for part of the journey so should get a long sea trial which will be good.

Thanks

This is the best way, an extended sea trail, you will be able to see what works and what needs doing.

 

[earlybird]

[QUOTE

A surveyor has said that as the engine has done 1500 hours he would like it removed and the head off, the owner thinks this is extreme as the engine uses no oil all season and runs fine. I really respect the vendor and his honesty in other areas so have no reason to doubt him.
[/QUOTE]

I think that taking an engine out and removing the head, merely on the basis of 1500 hrs running, is ridiculous. It will show nothing. The only benefit might be an opportunity to grind in the valves. IMHO, a compression test will yield very limited information unless a cylinder is very "down". Turning on the starting handle will give an idea of any variation.
If starting is good and little oil is used, ( OK, difficult to verify in the short term ), then I'd see the engine as in reasonable condition bearing in mind it's 20 yrs old. As already said, exhaust elbow condition is important.

 

[Bilgediver]

I think that taking an engine out and removing the head, merely on the basis of 1500 hrs running, is ridiculous. It will show nothing. The only benefit might be an opportunity to grind in the valves. IMHO, a compression test will yield very limited information unless a cylinder is very "down". Turning on the starting handle will give an idea of any variation.
If starting is good and little oil is used, ( OK, difficult to verify in the short term ), then I'd see the engine as in reasonable condition bearing in mind it's 20 yrs old. As already said, exhaust elbow condition is important.

I totally go along with this and as you will be paying for the removal of the elbow etc the cost of this survey will equal the cost of an elbow so to me seems daft when you can just make a fair offer to take these things into account. The will be especially so after doing your sail on the boat when you will become familiar with it.

 

[Georgio]

Hi Mike,
I agree with the above suggestions, with 1500 hrs on the clock head removal it likely to be of limited value.

When starting my 2GM from cold it is normally necessary to use full revs, although in the warm summer months my one starts easily at 2/3rds. From warm it will start at tickover or minimal revs. I have found that it's an engine that likes to be worked hard every now and then and runs so much sweeter if it has had a good few hours at 2,800 rpm rather than pottering along at 2000rpm all the time.

As a long-standing owner/sailor of a Co32 (with a 2GM) feel free to PM me with any further questions or queries you may have. If there is anything specific I'm happy to chat on the phone.

Best of luck.

George (official Co32 bore!)

 

[cid]

2gm

Hi I have a 2gmf and it needs full trottle from cold,then back to fast idle.In hot weather 1/2 will do.It also will start with no trottle once started.It burns no oil or none you would notice.I would feel your surveyor should know the starting proceedures.If you asked me to remove the engine to remove the head I would tell you and your surveyor to take a hike.
Regards CID

 

[RobW]

The fact that the engine starts first time is a good sign. The quantity and colour of any smoke in the exhaust is another, although this test is most useful under load.

I think with any 20 year old engine a bit of pot luck is involved, and as long as the purchase price of the boat reflects the age of the engine and the probable need for replacement in the next few years, you should be fine.

Rob.

 

[robbieg]

To be frank your surveyor sounds really over the top. Standard starting procedure for a many a Yanmar 2GM or 3GM is a lot of throttle to crank her and throttle back as soon as it fires. Particularly important if it is cold or the engine has sat for a while. Once warm she should start with minimal throttle.

Unless there is something other than having use full throttle to start from cold then to be frank I would be worried about a surveyor who seems to know so little about Yanmar GM's (a very common boat engine) that he is giving you the advice to remove the head.

If you are really concerned give a Yanmar dealer a call-most in my experience are quite helpful.

 

[SAWDOC]

My 2005 yanmar 2GM starts first time every time at tickover - in my opinion a great reliable no frills engine. By the way something to watch out for : my engine no has the prefix "E" which indicates an EU made engine making it a YEU Yanmar 2GM and different part nos apply than with the non EU models.

 

[toad]

As said most Yanmars like full or 3/4 throttle to start when cold, the greatest advantage of taking the head off is being able to clean the silt out of the water jacket if raw water cooled. It is well worth taking the injection bend off as part of routine maintenance to clean the carbon out as this will increase back pressure and make it harder to start. I believe this is part of the Yannmar service schedule anyway, about £5 for the gasket and a hours work. I would not be impressed by a surveyor wanting to take an engine apart in the circumstances you have outlined.

 

[MrCramp]

My 2GM20 needed full throttle when cold and the handbook said so. Had that boat for 7 years and the engine never missed a beat. A very good engine provided it is looked after properly. If you do a voyage try 30 minutes at full throttle and if you get no problems then I would think the engine is fine.