Yanmar 1GM10 not firing?

[conks01]

Hi

I've serviced my Yanmar 1GM10 on the Westerley Pageant this week.

The history is that I bought the boat in February. It wasn't until April that I fired up the engine. At that time is was working with the original diesel that the previous owner had left in (approx 2 years).

The engine fired up but it was not pumping water too cleverly.

I sucked out the original diesel and it has sat like that until today when I filled the tank with fresh diesel.

I have also replaced the impeller (previous was very badly worn so I think this was probably the problem with the poor water pumping situation), the anode and then the fuel filter attached to the engine.

When I replaced the fuel filter I sat the new one in the bowl full of fresh diesel. I then released the bleed screws, stage by stage albeit that I noticed that when using the fuel pump lift no diesel or bubbles were evident from the bleed screws (?).

Today the plan was to start the engine to warm up the oil before siphoning the oil out but the engine wouldn't fire. It turned over but no start.

I then proceeded to try and crank the engine by lifting the decompression lever. What I noticed was that the handle went from 12 o'clock position to say 7 o'clock position but then stopped. It took a lot of effort then to get it from 7 position all the way round. When it did this again it got stuck at 7 o'clock position.

My first question is why this would be. My understanding is that the crank should rotate freely, which it didn't.

The second question and as aforementioned, why I couldn't draw any fuel, or bubbles, from the bleed screws.

I've included below a video of the start up.

https://www.youtube.com/watch?v=82LsZmEFYCM

All help & advice greatly appreciated.

Thanks.

 

[greggron]

Link does not appear to work

 

[conks01]

Thanks - I've since uploaded to Youtube instead.:encouragement:

 

[neil_s]

No fuel at the bleed screws - a quick comment. The fuel lift pump on my Bukh engine needs a good hard press to pump. It taunts you by moving easily at first under your finger, but to get it to really pump you need to press hard!

 

[earlybird]

Couple of quick thoughts. It seems as if your decompression lever isn't operating on the exhaust valve. You'll need to remove the rocker cover to see if that's so. The handle rotates the engine at 2x speed, so a compression stroke will be felt at each revolution.
I'd guess that you havn't bled the fuel filter, and the rest of the system fully. Takes a lot of pump waggling, try with a different crankshaft position as well.

 

[VicS]

Hi

I've serviced my Yanmar 1GM10 on the Westerley Pageant this week.

The history is that I bought the boat in February. It wasn't until April that I fired up the engine. At that time is was working with the original diesel that the previous owner had left in (approx 2 years).

The engine fired up but it was not pumping water too cleverly.

I sucked out the original diesel and it has sat like that until today when I filled the tank with fresh diesel.

I have also replaced the impeller (previous was very badly worn so I think this was probably the problem with the poor water pumping situation), the anode and then the fuel filter attached to the engine.

When I replaced the fuel filter I sat the new one in the bowl full of fresh diesel. I then released the bleed screws, stage by stage albeit that I noticed that when using the fuel pump lift no diesel or bubbles were evident from the bleed screws (?).

Today the plan was to start the engine to warm up the oil before siphoning the oil out but the engine wouldn't fire. It turned over but no start.

I then proceeded to try and crank the engine by lifting the decompression lever. What I noticed was that the handle went from 12 o'clock position to say 7 o'clock position but then stopped. It took a lot of effort then to get it from 7 position all the way round. When it did this again it got stuck at 7 o'clock position.

My first question is why this would be. My understanding is that the crank should rotate freely, which it didn't.

The second question and as aforementioned, why I couldn't draw any fuel, or bubbles, from the bleed screws.

I've included below a video of the start up.

https://www.youtube.com/watch?v=82LsZmEFYCM

All help & advice greatly appreciated.

Thanks.

All the video shows is an engine being cranked but not starting !

You may not be bleeding the fuel system because the lift pump is already on the toe of the cam. Turn the engine through one complete revolution of the crankshaft, in its normal direction, and try again but note what neil says about requiring some effort to operate the pump after taking up any free movement.

The decompression lever is in the "no compression" position when vertical and in the running position when horizontal ( see the diagram in the owners manual). It should only turn through 90°

 

[Topcat47]

1. If the lift pump is on the cam you can waggle the lever as much as you like but it won't pump fuel up to the fine filter. Turning the engine by hand will rotate the cam and allow you to operate the lift pump through its range of movement. This should result in fuel reaching the bleed screw of the fine filter. Then continue to pump until fuel emerges from the bleed screw of the fuel pump. After this turning the engine over on the starter motor will eventually get fuel up to the injector. I usually turn the engine over by hand with the olive on the injector cracked until fuel spills out here.

2. Unless you hold the decompressor open as you turn the engine, it will close and you will get compression. It's spring loaded and automatically returns to the off position when you release it.

 

[tillergirl]

Frankly, having listened to the video and having (inter alia) a 1GM my first reaction is that it is decompressing. Diagnosis by sounds isn't the best but that's how it sounds to me. Given how far you pushed the lever over, it might have stuck down.

 

[Tranona]

Nothing seems wrong with starting except that you have no fuel. Do as Topcat suggests and bleed it by turning the engine over with first the pump bleed open and then the injector cracked open. once fuel is coming out of the injector it will start.

Just one other thing to look at. If you have changed the filter on the engine make sure the sealing ring is properly seated. This is a common thing to get wrong and will result in air getting in.

 

[conks01]

All - Many thanks. Yes it was air. Managed to (eventually) bleed all 3 positions and it then fired. The lift lever valve was actually stuck so manager to take the lift pump off and clear it. Then the laborious task of pumping the lever until (after almost 15 mins) fuel spilt out of the first bleed screw. It ran for about 5 mins before giving up. That's because I inadvertently turned off the fuel stopcock! Doh! Thanks.

 

[Topcat47]

All - Many thanks. Yes it was air. Managed to (eventually) bleed all 3 positions and it then fired. The lift lever valve was actually stuck so manager to take the lift pump off and clear it. Then the laborious task of pumping the lever until (after almost 15 mins) fuel spilt out of the first bleed screw. It ran for about 5 mins before giving up. That's because I inadvertently turned off the fuel stopcock! Doh! Thanks.

Easily done. I've had many a "Doh!" moment myself.

 

[JumbleDuck]

All - Many thanks. Yes it was air. Managed to (eventually) bleed all 3 positions and it then fired. The lift lever valve was actually stuck so manager to take the lift pump off and clear it. Then the laborious task of pumping the lever until (after almost 15 mins) fuel spilt out of the first bleed screw. It ran for about 5 mins before giving up. That's because I inadvertently turned off the fuel stopcock! Doh! Thanks.

Congratulations!

 

[Major_Clanger]

Make sure you check the integrity of the oil line which runs beneath the water pump housing to the sump. They are known to corrode badly and can write-off the engine if they fail. Thankfully quite cheap to replace though.

 

[agurney]

Make sure you check the integrity of the oil line which runs beneath the water pump housing to the sump. They are known to corrode badly and can write-off the engine if they fail. Thankfully quite cheap to replace though.

.. but don't replace them with Yanmar steel ones, find a local hydraulic shop and have them made from hose.

 

[JumbleDuck]

.. but don't replace them with Yanmar steel ones, find a local hydraulic shop and have them made from hose.

Pirtek made both for me while I waited for about £35. That included longer banjo bolts, needed because their end fittings were thicker than the Yanmar ones.