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drbgd · 01-09-2019, 14:21

Dear forum,

I'm troubleshooting some fuel leakage problems with my Yanmar 2GM and in the process I've noticed a screw came loose - found it in the tray under the engine. Anyone has any idea where it belongs and - hopefully - it has something to do with the fuel system?

Cheers,
Andy

**skipperpete** · 02-09-2019, 18:04

Quote:

Originally Posted by drbgd

Dear forum,

I'm troubleshooting some fuel leakage problems with my Yanmar 2GM and in the process I've noticed a screw came loose - found it in the tray under the engine. Anyone has any idea where it belongs and - hopefully - it has something to do with the fuel system?

Cheers,

Andy

It looks like a damper plate retaining screw but how it got out of the flywheel housing is difficult to explain. Happily, if you have a KM2 gearbox, the damper plate and retaining screws can be viewed through the aperture on the gearbox mounting flange.

**Wotname** · 02-09-2019, 18:17

It doesn't look to be part of the 2GM Yanmar fuel system to me and it looks like the internal hex is worn - perhaps it was dropped by a PO and replaced with a good one.

Maybe Skipperpete is correct and it was left in the engine tray during a previous repair.

**sailorchic34** · 02-09-2019, 20:14

if it came from the engine, the only two possible locations would be the water pump">raw water pump impeller cover, or perhaps a securing screw for the throttle or engine stop cables. it's not something you would normally see on a Yanmar GM series engine.

dennismenace111 · 03-09-2019, 08:24

Ive found lots of loose screws since I started working on my boat... Usually theyre mine.

Martkimwat · 03-09-2019, 10:53

They look like small cap screws and I cannot think of any cap screws on the 2GM, and I've had mine largely stripped down before I installed it (second hand). Even the cable pinch screws are normal bolts as are the cable clamps that hold the gear and throttle cables to their respective brackets. The fuel pump is held on with I think 10mm headed bolts which means M6 threads and they look like M4 or M5 threads on the ones he is holding. The fuel pump itself has I think three small screws (M4?)that hold the two parts of the diaphragm together, but they are Phillips headed as I recall. It's possible that a PO had it apart and lost or replaced a screw with a cap screw and that is where it has come from. Would explain a fuel leak.

Compass790 · 03-09-2019, 16:49

No idea about yr loose screw but I found wrapping all the joints in dunny paper & pressurising system with outboard squeeze bulb was a good way to find leaks.
When we bought the boat about 75% of the joints were leaking.