Stuck governor?

[Bottleveg]

Hello all.
I’m after a bit of advice from those who know more than me!
I have only started my 8/1 SOM briefly a few times since I've had it and it's, I think, going up to full revs with no load on.
The governor lever by the oil pump doesn’t move. My understanding is that the engine starts on full revs and then the governor regulates it. If my thinking is correct then my Q is- is the governor stuck and, if so, how do I un-stick it?

       Mark.

[Tijean]

When engine is stopped, there is no centrifugal force and the external governor regulating spring should have the rack pulled wide open (if the shut down cam is in the lowered position) and the weights inside should be in the inward position and the transfer collar should be slid to the one extreme of travel. You should be able to move the linkage back and forth against the spring. It is possible that the flanged collar sliding on the cam shaft (which engages both the inner end of the flyball weights and the end of the external linkage finger) could be stuck and not free to slide. Have you disconnected the linkage to the injector pump fuel rack to make sure it is not seized?

It could be seized inside or a weight lever pin askew or possibly misassembled with a finger on the wrong side of a flange.

[oliver90owner]

Do you mean the engine is over-speeding?  If spoked flywheels, in particular (but not exclusively), beware of the dangers of flywheel disintegration.  Presumably your flywheels are solid on a SOM.

The engine should govern at design operating speed whether loaded or not.  Check the alternator output frequency value(Hertz) with a meter or whatever if you are not sure.

Regards, RAB

[ronmar]

Are you sure it is overspeeding?  If not familliar with a normal running sound, you may not be actually getting to full RPM.  The mechanical governor will hold the rack at full throttle till very near the governed RPM.  As RAB suggested, get a freq counter on the generator output and look for rated generation frequency.  You are not overspeeding till you get above rated frequency...

[Bottleveg]

Thanks for your replies. When the SOM solenoid activates and the engine starts, the rack on the fuel pump moves to fully open and stops there. The ‘L’ linkage on the governor doesn’t move at all (when running or by hand). Should the weights inside be movable by hand? It has been standing for ten years and the pump tappets were stuck so I wouldn’t be surprised if something else was. It may be running at normal speed but it seems like a lot faster, and noisier than those on Utube. I expected the revs to fall after starting. I don’t have a meter so can’t check the frequency.

[Tijean]

Thanks for your replies. When the SOM solenoid activates and the engine starts, the rack on the fuel pump moves to fully open and stops there. The ‘L’ linkage on the governor doesn’t move at all (when running or by hand)    . Should the weights inside be movable by hand?    It has been standing for ten years and the pump tappets were stuck so I wouldn’t be surprised if something else was. It may be running at normal speed but it seems like a lot faster, and noisier than those on Utube. I expected the revs to fall after starting. I don’t have a meter so can’t check the frequency.

Yes, free to move. The fuel rack on the injector pump also must be free to move. If not you have a problem and have to determine where the binding is

[Bottleveg]

Thanks for your replies. When the SOM solenoid activates and the engine starts, the rack on the fuel pump moves to fully open and stops there. The ‘L’ linkage on the governor doesn’t move at all (when running or by hand)    . Should the weights inside be movable by hand?    It has been standing for ten years and the pump tappets were stuck so I wouldn’t be surprised if something else was. It may be running at normal speed but it seems like a lot faster, and noisier than those on Utube. I expected the revs to fall after starting. I don’t have a meter so can’t check the frequency.

Yes, free to move. The fuel rack on the injector pump also must be free to move. If not you have a problem and have to determine where the binding is

Thank you for the info Tijean,
The fuel rack moves freely, fully closed when off and fully open when running, but the internal weights will not move and the external lever, that holds the governor spring only moves a fraction to take up the ‘slack’. So this would result in over speeding?
My guess is that it is stuck inside on the transfer collar that you mention? The pump tappet was stuck solid with dry oil. Is there an easy cure or is it time to take the flywheel and cover off?

[billypurves]

Hi Mark,  In my opinon your governer is stuck, or the linkages presuming the injector pump rack is free.Or as it has been suggested ,wrongly put back together.
  I always check to see if the governers are free before I fire up any stationary engine,amazing how heavy an engine gets it when it is bouncing on the workshop floor.

[Tijean]

The "at rest" position of the system is the external balance spring pulls the rack full wide open and pulls the fly ball weights in. That is by far the most likely position for it to be gummed or rusted in.

I think it would be a good idea to have it apart; You might manage to bang it loose from the outside but you also want to be certain that the engaging ball on the inside governor lever is free to rotate as it rides the flanges of the sliding collar.

[Bottleveg]

Hi Mark,  In my opinon your governer is stuck, or the linkages presuming the injector pump rack is free.Or as it has been suggested ,wrongly put back together.
  I always check to see if the governers are free before I fire up any stationary engine,amazing how heavy an engine gets it when it is bouncing on the workshop floor.

Hi Billypurves, yes it’s looking like a stuck governor. As far as I know, the engine hasn’t been apart, maybe since it was made in ’62. This is my first Lister so I’m on a learning kerb. Fortunately I shut it down before it went too fast!

  Mark.

[Bottleveg]

The "at rest" position of the system is the external balance spring pulls the rack full wide open and pulls the fly ball weights in. That is by far the most likely position for it to be gummed or rusted in.

I think it would be a good idea to have it apart; You might manage to bang it loose from the outside but you also want to be certain that the engaging ball on the inside governor lever is free to rotate as it rides the flanges of the sliding collar.

Yes, it’s in the ‘at rest’ position with the balls weights in. I’ll take it apart and see what’s stuck. From what I can see dismantling involves removing flywheel, fuel pipes, oil pipes, securing bolts and then the cover slides off the shaft?
I’ll see if I can find the drawing on Lister_CSOG.
              Thanks for your help.

[listeroil]

I have managed to remove the cam cover on a 8/1 engined SOM without removing the flywheel.
Remove the pin that the pump quadrant sits on and them remove the studs that hold the camcover and you should be able to remove it.
Use 2 nuts tightened together to remove the studs.

Mick

[Tijean]

From what I can see dismantling involves removing flywheel, fuel pipes, oil pipes, securing bolts and then the cover slides off the shaft?
I’ll see if I can find the drawing on Lister_CSOG.
              Thanks for your help.

You should be able to leave the oil pump and lines intact but injector pump and fuel lines will have to go. The cover on the opposite end of the cam could be removed as described without disturbing that flywheel but the one that houses the governor linkage would have to come straight out a long ways to clear the camshaft before it could be lifted so I am quite sure you will have to have the flywheel off on this end. My experience has been entirely on the Listeroid version though.

[Bottleveg]

Problem solved. I soaked the area in penetrating oil overnight and managed to free it all up from inside the engine, so all is moving freely as it should.
The engine is now running at a much lower speed, a lot quieter and regulated by the governor.
Thanks all for the advice; I’ve now learnt some more about these wonderful engines.

[Tijean]

Problem solved. I soaked the area in penetrating oil overnight and managed to free it all up from inside the engine, so all is moving freely as it should.
The engine is now running at a much lower speed, a lot quieter and regulated by the governor.
Thanks all for the advice; I’ve now learnt some more about these wonderful engines.

It is good that you got to the root of the over speed problem; That is not to be trifled with.

I have to be the Grinch here a bit though. My concern is that the roller on the inside lever will be seized. That appears to be "not broken" so why fix it, but if it is not rolling freely it will quickly flat spot where it contacts the collar and lost motion in the linkage then starts to develop prematurely.