Background:
The engine is a Yanmar 2GMF20 with about 2500 hours. During a 26 month re-fit on the boat (150 engine hours ago) the following was done: All new fuel system, filters, and lines, tank boiled out, new filler hose and vent.
The engine ran perfectly for 150 hours before displaying stalling symptoms. All filters were changed and the system bled as per the manual.
I still have a problem.
From a cold engine the following happens:
Fires up easily and idles smoothly.
In gear and up to cruising rpm ... smooth and lots of power.
After 5 to 7 minutes engine starts to loose rpm and then stalls.
After immediate re-starting will not idle without some additional throttle, and needs full throttle to push the prop.
Leave it for an hour or two and the whole process repeats, but only runs about 5 minutes.
It feels like a fuel starvation problem. The only hose that has never been replaced is the one between the engine filter and the injector pump. I´ve ordered a new one and also a new lift pump, although the existing lift pump seems to work perfectly.
Other checks I´ve made are:
Fuel tank pickup and line: clear.
Fuel return line: clear and plumbed into top of tank.
Tank vent and hose: clear
Lift pump primer lever: working well.
As it runs so well at first I don´t suspect the injector pump, but I´ve run out of ideas.
Any and all help greatly appreciated!
Peter.
The engine is a Yanmar 2GMF20 with about 2500 hours. During a 26 month re-fit on the boat (150 engine hours ago) the following was done: All new fuel system, filters, and lines, tank boiled out, new filler hose and vent.
The engine ran perfectly for 150 hours before displaying stalling symptoms. All filters were changed and the system bled as per the manual.
I still have a problem.
From a cold engine the following happens:
Fires up easily and idles smoothly.
In gear and up to cruising rpm ... smooth and lots of power.
After 5 to 7 minutes engine starts to loose rpm and then stalls.
After immediate re-starting will not idle without some additional throttle, and needs full throttle to push the prop.
Leave it for an hour or two and the whole process repeats, but only runs about 5 minutes.
It feels like a fuel starvation problem. The only hose that has never been replaced is the one between the engine filter and the injector pump. I´ve ordered a new one and also a new lift pump, although the existing lift pump seems to work perfectly.
Other checks I´ve made are:
Fuel tank pickup and line: clear.
Fuel return line: clear and plumbed into top of tank.
Tank vent and hose: clear
Lift pump primer lever: working well.
As it runs so well at first I don´t suspect the injector pump, but I´ve run out of ideas.
Any and all help greatly appreciated!
Peter.