2 cylinder yanmar help

[motion30]

I need some help. With a two cylinder Yanmar that's in my buddies 30 ft Catalina. It ran okay and then he did not run it for a while maybe a month or so and it would not start. So he pulled the injectors and took them to the shop and had those serviced. Put back together no difference. He then pull the injector pump and had it serviced, still no difference. Today I got involved. I tried to bleed the fuel system starting at the fuel filter and then proceeding to the fuel injectors. It has an electric fuel pump, and the mechanical pump is disconnected. It seems I have plenty of fuel going into the fuel pump. But it barely Spitz coming out of the injector pump. We got it to the point where it will start but I cannot make any RPM and then it shuts off . But it does seem like it will start again but just will not rev up. I'm looking for some suggestions also in the front of the injector pump is a bolt I believe that is some kind of adjustment maybe someone knows what that is see picture below

[Wotname]

AFAIK, the "bolt" you are pointing at should never be touched (i.e. adjusted) in normal circumstances. I'm a bit hazy on the details but I sort of recall that is adjusts the fuel delivered at WOT or said another way, delivers the correct amount of fuel to achieve the desired hp at max rpm and as such is set by Yanmar. If this is incorrect, I'm sure wiser counsel will post accordingly.

Have you changed out the engine mounted fuel filter?

Are you getting plenty of fuel delivered to the Injector Pump (not the fuel pump) when you crack the bleed screw at the Injector Pump? If not find out why.

Have you bleed the injector fuel lines at the injector?

Is the fuel cut off lever on the Injector Pump correctly adjusted?

[motion30]

Hostname
Unfortunately I came into this project after that screw had already been full breath. When you say. The fuel shut off lever are you referring to the throttle lever? I am very mechanical and have owned an outboard shop myself but I I'm not familiar with the. Yanmars.

[motion30]

And unfortunately I do not have a shop manual. I'm trying to get this damn thing running so we can both take our boats to Key West

[Wotname]

Here is part of the manual for GM and HM engines

The bolt is the fuel injector limiter and is normally safety wired!

[Wotname]

Originally Posted by motion30

Hostname
Unfortunately I came into this project after that screw had already been full breath. When you say. The fuel shut off lever are you referring to the throttle lever? I am very mechanical and have owned an outboard shop myself but I I'm not familiar with the. Yanmars.

What model engine is it? t looks like a 2GM or a 2GM20

GMs have a seperate lever for the engine stop.

I have a few different manuals if you need one emailed.

[Seymore]

How old is the fuel? There might be sediment plugging the filters and fuel feed system.

[skipperpete]

Hi motion30, hate to state the obvious but are the decompression levers in the "run" position?

[motion30]

Yes. The decompression levers are closed

[JimsCAL]

My guess would be either plugged fuel filter(s) or air in the fuel system. With all the work that has been done, a careful bleed is necessary. The two main bleed points are on the engine fuel filter and on the injection pump. Generally that is enough, but you may have to bleed the lines going to the injectors since those were taken off.

[skipperpete]

There's another possibility .....when the injector pump was reinstalled , the fuel control pin on the pump rack must enter a small yoke that connects the pump to the governor. If the pin misses the yoke and consequently loses governor control, the engine will either run away and damage itself badly or more happily will behave as you describe, it just depends on which side of the yoke the pin happens to end up. Operating the stop control should cut off all fuel from the injector pump and is a necessary step when fitting a pump before attempting a start

[motion30]

Originally Posted by JimsCAL

My guess would be either plugged fuel filter(s) or air in the fuel system. With all the work that has been done, a careful bleed is necessary. The two main bleed points are on the engine fuel filter and on the injection pump. Generally that is enough, but you may have to bleed the lines going to the injectors since those were taken off.

Yeah I have blood it through the nuts on the injector piping but I cannot identify a screw to bleed the pump itself

[motion30]

Originally Posted by skipperpete

There's another possibility .....when the injector pump was reinstalled , the fuel control pin on the pump rack must enter a small yoke that connects the pump to the governor. If the pin misses the yoke and consequently loses governor control, the engine will either run away and damage itself badly or more happily will behave as you describe, it just depends on which side of the yoke the pin happens to end up. Operating the stop control should cut off all fuel from the injector pump and is a necessary step when fitting a pump before attempting a start

Yes. I did consider that and in fact a pulled the pump out to check I'm pretty sure I have it lined up but of course you cannot be positive with that design I don't think there is a way to verify

[JimsCAL]

Originally Posted by motion30

Yeah I have blood it through the nuts on the injector piping but I cannot identify a screw to bleed the pump itself

My 3GM30 has a bleed point on the injector pump. It's something like a 9mm hex bolt. For some reason the owners manual I have (which also covers the 2GM) does not mention it in the bleed procedure. See if you can find a drawing on the web someplace for that engine.

[NYSail]

Bleeding is important and actually unite simple on a Yanmar especially if you have an electric fuel pump..... but it you altered “that screw” on the injector pump you now have other issues that a professional should be consults with (at least that is what I have always been told).

Good luck

Greg