The Yanmar 1GM

[Tracuman]

Hi folks,
First, Thanks again for all the advice over the months.
I was able to start the engine on Callipygian yesterday after a couple of hours bleeding fuel lines, etc. I got good advice from searching the posts about basic stuff. Now I need to hear from owners of this particular diesel. Tell me about how it runs at low RPM (less than 1000) and what it should sound like. I ran it for about an hour yesterday at 900 and eventually the black smoke changed to almost clear. There was also a steady "thud" which I think is what it should sound like. It didn't overheat and eventually the sound was quieter (or I just got used to it). My limited knowledge of this engine is that it's noisy, but I also read in the manual that it was "quieter operating than previous models". Since it's been at least 8 years without running, I expect to need to burn some carbon, I'm just not sure that's all I should do.
Thanks for any input.
John

[barfwinkle]

That's what mine sounds like! And yes it will even out once she warms up and the rpms go up to around 1100 she really smooths out.

When I first start mine (esp in cold weather) there is a noticeable "knock" until she warms up a bit, then it all smooths out again (of course it is a one lunger and is going to make some noise).

Merry Christmas

[Kurt]

John,
I've heard from several sources that idling a diesel for extended periods of time is not good for it. You'd be better off running it at a higher rpm if you want to run it while the boats stationary. When big trucks idle all night long while parked in rest stops in the dead of winter, they are running on a fast idle...not slow idle.
Kurt

[car1260]

Our's sounds like the African Queen! Anyway, we always idle up over 1000 rpm's after she kicks over. We also keep the rpm's over 1000 if we are going to be idling more than a couple of minutes(like when waiting for a bridge opening). I believe you live nearby in Tampa. We have an 1983 25D in Sarasota & use Runkel Deisel in Bradenton for all our parts for the Yanmar. Greg is the owner and is always willing to help over the phone with any problems. We bought Yolo and decided that since she had other deferred maintainence issues we would just go thru the engine & replace everything that could be trouble...All the old parts(except the filters) are now our spares. We replaced the injector, fuel lift pump, oil filter, air filter, thermostat, temp sensor, mixing elbow, the impellor, new racor fuel/water seperator & new altenator belt. It all cost about $300 thru Runkel not including our labor of course! Anyway she runs like a champ and we now know that we have the tools & spares onboard to fix most of the things that go wrong with the 1GM. I highly reccomend that you change the mixing elbow if nothing else. Greg says that people think they can just inspect it, but you can not see inbetween the 2 pipes in the elbow to see if there is any corrosion. That is where he sees them fail which allows water into the cylinder & ruins the engine. Send us a pm, maybe we can sail our 25D's out on Tampa Bay together sometime?

[Ray Garcia]

Our CD27 has been shored up at home since last November for a refit. I started the motor over the summer after winterizing her last year. The motor started right up on the first turn of the key. The motor in my opinion is indestructible. I ran it again periodically over the summer to keep things lubricated. Last month I winterized the motor again before the silence of snow and cold takes over. On the first start I saw black smoke and a loud knock, it was a cold day when I started the motor. Once she warmed up the motor smoothed itself out. I added a link below to how the motor sounded when I was working on winterizing.

Keep up with the maintenance (oil, filters, and fresh diesel) and it should run forever.

Note: You will need a broadband or better internet connection.

Click here for YSM8 Movie

.

[rtbates]

They are thumpers for sure and at low speed they tend to sound like the old steam engine from the African Queen. They also like to be used. One of the best things you can do for it and any diesel for that matter, is go out and run it for a good hour or so at say 2000 rpm. When I first bought Seraph her 1GM wouldn't run over 2500 rpm without lots of smoke. I cured that by motor sailing one day for four hours turning at about 1500 rpms. She'll now run up to 3500 rpms.

[Tracuman]

Thanks for the quick feedback. Now I'm feeling a bit better. Already replaced most of those parts, and will add a few. Do any of you see a problem with me running this engine while she's on the hard for extended periods as long as I'm supplying cooling water and checking things. I'm still refitting her, but it sounds like some higher RPM running might clean things out a bit and certainly wont hurt...what do you think?

[rtbates]

Thanks for the quick feedback. Now I'm feeling a bit better. Already replaced most of those parts, and will add a few. Do any of you see a problem with me running this engine while she's on the hard for extended periods as long as I'm supplying cooling water and checking things. I'm still refitting her, but it sounds like some higher RPM running might clean things out a bit and certainly wont hurt...what do you think?

A 'little bit' of running shouldn't hurt, but you don't want to let it idle for long periods w/o any load. It's a recipe for carbon build up.