Issue with yanmar 3gm30f

[Ed D]

When I increase the RPM to 2600 t02800 the motor runs fine for about 5 minutes than it sounds like it is going to cut out for a second and the continues running If I reduce the RPM to around 2200 to 2500 RPM runs fina all day long

Have checked the following by a yanmar mechanic

All fuel filters on good condition

Had the fuel polished and record rebuilt

Cannot fin air lock

Does anybody have an idea of what this issue is and maybe causing it


ED

 

[woodster]

When I increase the RPM to 2600 t02800 the motor runs fine for about 5 minutes than it sounds like it is going to cut out for a second and the continues running If I reduce the RPM to around 2200 to 2500 RPM runs fina all day long

Have checked the following by a yanmar mechanic

All fuel filters on good condition

Had the fuel polished and record rebuilt

Cannot fin air lock

Does anybody have an idea of what this issue is and maybe causing it


ED

how old is the mixing elbow on the exhaust it sounds like yours is getting clogged up and may need cleaning or replaced

 

[Johnb]

Another possibility - my 3qm30 showed similar behavior that went away when I replaced the fuel pump. My conclusion is it was just marginal fuel starvation that did not manifest except at close to full power.

 

[kloudie1]

Usually not enough fuel to sustain a heavy load. Could be the lift pump, could be the fuel line(s) between the tank and the pump either collapsing or may have tiny cracks in it.. could be a few other things affecting fuel to the injector pump. I don't know if that model had a metal gauze in the fuel pick-up tube in the tank but that may be a cause.. if it plugs just a little, it will do what you are describing.. Happy hunting !

 

[Ed D]

Thank you

Mixing elbow about four years old no overheating issues

 

[Ralph Johnstone]

This Miserable Little ......................

Thank you

Mixing elbow about four years old no overheating issues

............... ^$%&*\!$ is the easiest item to check and a likely cause of your problems.

Note that the water passage on an elbow can be reasonably clear hence no overheating, but the gas passage can be plugged. The fact that this one worked without causing any engine problems whatsoever is proof of supernatural intervention .

 

[Ed D]

............... ^$%&*\!$ is the easiest item to check and a likely cause of your problems.

Note that the water passage on an elbow can be reasonably clear hence no overheating, but the gas passage can be plugged. The fact that this one worked without causing any engine problems whatsoever is proof of supernatural intervention .

Hi


Thank you sound advice

 

[Nelsonhow]

I would check for:

An air leak due to a cracked or loose fuel line

An air leak due to a poorly seated filter gasket

A dirty pick up screen in the fuel tank.

 

[Ed D]

Thanks for all suggestions

Found out have a compression problem in no 1 cylinder Was having starting issues also Solution I am re powering with a new 3ym30ae with new transmission