Injection Pump Govenor

[Paul F]

Hi All,

Can anyone please explain how the GOVENOR part of the injection pump works, and what it does to control the engine ?

Regards, Paul

[gonzo]

It controls fuel flow to keep RPM's constant. Mechanical systems work with centrifugal weights, electronic systems work with a sensor.

[Paul F]

Thanks Gonzo, so does the " throttle " leaver increase fuel flow or does it control speed of the govenor.

[gonzo]

It controls the governor. Think of it as a cruise control in a car.

[Paul F]

That's obviously why it is easier to maintain constant RPM in a diesel engine when compared to a petrol, particularly with a carb.

[michael pierzga]

The govenor also keep a diesel engine from running out of control.

[Paul F]

Originally Posted by michael pierzga

The govenor also keep a diesel engine from running out of control.

Ah, so it controls and LIMITS the RPM, hence the name " govenor " to govern the revs.

Thanks, I'm learning more. I'm just trying to make sure that with proper use my engine will give me many hours / years service.

Regards, Paul

[FAST FRED]

There are two types of units .

One will attempt to keep the RPM the operator set.

The other limits the HP (fuel flow) to the set point and will allow the RPM to drop under load.

[michael pierzga]

Yes indeed...two types, functions for a govenor. One chokes off fuel supply, the other regulates it.

[powerabout]

Originally Posted by michael pierzga

Yes indeed...two types, functions for a govenor. One chokes off fuel supply, the other regulates it.

Not quite there are constant speed governers - gen sets etc
and variable speed like cars trucks and propulsion engines

[CatBuilder]

Where does one find a variable speed governor for a Yanmar 3YM30 engine?

That would be the type that you set at say, 1800 RPM to run a generator.

[powerabout]

gen set needs a constant speed governer
EDIT ones that holds the engine at a constant speed

[CatBuilder]

Originally Posted by powerabout

gen set needs a constant speed governer

No....

Link

"The variable speed mechanical governor is found extensively on industrial and marine applications, since it is designed for the following functions:

Controls the engine idle speed
Controls the maximum engine speed hydraulic-type governors (industrial and generator sets)
Holds the engine speed at any position between idle and maximum as desired and set by the operator."

Any idea where to buy one for a Yanmar 3YM30?

[powerabout]

ok its a terminology thing
you buy a variable speed governor to hold the engine at constant speed with very little droop

and a constant speed supplies constant fuel supply so load increases and the engine slows down

my bad

[powerabout]

Originally Posted by CatBuilder

No....

Link

"The variable speed mechanical governor is found extensively on industrial and marine applications, since it is designed for the following functions:

Controls the engine idle speed
Controls the maximum engine speed hydraulic-type governors (industrial and generator sets)
Holds the engine speed at any position between idle and maximum as desired and set by the operator."

Any idea where to buy one for a Yanmar 3YM30?

If its internal jerk pump style then it would be yanmar, its its external inline or rotary you could speak with the pump manufacturer
so how about we just say you want a governor with only a few percent droop
Looks like the Yam has en external inline pump so start with the pump manufacturer