Governor problem, help/comments welcome

[altopro]

Hello Guys,

Engine: Standard Listeroids 6/1

This is the case, adjusting the governor with a 150W load for 120V at 600RPM works fine.
Adding a 1500W load and the engine can't keep the speed, voltage drops to 100V. It's even worst when adding up to 3000W.

Adjusting the governor for 600RPM at 1500W works fine, dropping back to 150W and engine over-speeds...

My first thought is that something could be stock in the governor weights but it might be a spring issue.

Your experience and comments are welcome. Maybe someone had the same before.

Thanks,

PAT

[fuddyduddy]

Why re-invent the wheel?

Go to http://www.utterpower.com/governor_kit.htm , and buy George's fix for the governor. Dirt cheap, simple, and it works.

If $10 is too much, the free info is at http://www.utterpower.com/gov_mod.htm

Fuddy Duddy

[altopro]

Hello fuddyduddy,

Thanks for your comments. My understanding is that this specific mod will improve the accuracy of the governor, specifically the response time. In the above case, the governor has no accuracy at all. Going from 150W to 1500W and the engine can't keep the speed. I'm not talking about the usual +/- 5% play in the governor response when dropping a large load.

Would you think it could be something with the governor weights not moving freely?

Cheers,

Pat

[t19]

check for paint??

[fuddyduddy]

Try the simple stuff first; am not sure 5% is very accurate on response. Maybe up to +- 10% in some cases. Jack B, and some others can tell you FAR better than I about loads and voltage.

Some heads do better than others, also. George has postings (or info on the CD) on ST heads with AVR circuitry; they do not do very well.
Fuddy Duddy

[altopro]

t19,
Paint is not the problem.

fuddyduddy,
I don't think this has anything to do at all with the device being powered by the engine (In this case a generator head). You could be using the engine to drive a saw mill or other machine. The point is that speed it dropping by half when adding a small load on the engine and speed will double when taking the load off. Making it go faster than rated speed.

Thanks again

[albany dbd]

Id try a weaker spring. the softer spring rate will let the govener work faster although if you get to soft it will hunt when the load changes fast. its a trade of soft means more accrate but more likely to hunt.

[hotater]

Watch out now!!  Softer springs mean the weight might overpower the spring and run a way.  Govornors are a balancing act.

Governor test:  Crank the engine and let it warm a few minutes, now, using you fingers, pull the govenor arm one way and push the other.  You should feel a definite resistance and 'push back' in both directions as the weights change position with rpm.

I can't quantify the resistance but it feels 'alive' in that it increases resistance as more pressure is exerted.

Mine has just taken to occilating with each power stroke...under load, a full quarter inch total travel.  I've got it shut down to see what's going on.  Anybody else had one start 'pumping iron'?

[albany dbd]

its the spring that pulls the rack open softer spring wont not pull as hard. Ive tried lots of springs i can drop a 2500 watt load and the motor hardly rises rpm at all not enough to hear a difference in rmp just a difference in tone.

[cujet]

I have had good results with changing the original spring. The rate curve for the OEM spring is too steep to maintain control over a full load. It is not a softer spring you want. It is a more linear spring you want.

Consider this: A strong spring provides stability by quickly and positively correcting for speed fluctuations. However as the spring is asked to stretch, it has much more tension and vice versa. At some point the distance the rack must travel (to achieve rated RPM at high load) reduces spring tension and RPM droops.

Mike Montieth (Listeroid USA) posted a simple adjustment for sensitivity a while back. Try this too.

Chris

[albany dbd]

the spring is stretched the most under no load. the slower the engine is to run the softer the spring.

[Jim Mc]

Use a weaker, longer spring.  Worked fine for me.

[Doug]

On any mechanical govener the further you move the springaway from the pivat point the less spring tension you need and the more sensitive it becomes to load changes. I don't have a Lister but this is the fix for most other types of engine. The only down side is some engines will hunt at light load when you do this....

Doug

[JohnF13]

Two things come to mind - first you are running at 600 rpm instead of the standard 650 - that gives you a lot less power and may result in a wider range of voltage.  Second thing, (after you do the govenor mod upgrade) is that there MAY be a problem with the govenor weights.  I have seen several govenors working badly because the split pin holding the weight pin in place breaks (they are too thin and should be replaced on every engine!) - that results in the pin dropping sown and the weight skewing sideways.  It won't drop out, the pin can only go so far and is held in place by the casing, but it will result in very poor governor response.

One other thing you could try - set the engine up for your nominal voltage/frequency (I recommend 61hz and about 120 volts, YMMV) at no or minimal load, apply your bigger load (say 3kw) and see what the the engine does - if it slows and will not get back up to speed, try manually opening the fuel rack to see if it will pick up.  If it does, then most likely your culprit is the govenor mechanism.

[altopro]

JohnF13,

Thanks for your input. I think that you have a good point with the pin issue.

One other thing you could try - set the engine up for your nominal voltage/frequency (I recommend 61hz and about 120 volts, YMMV) at no or minimal load, apply your bigger load (say 3kw) and see what the the engine does - if it slows and will not get back up to speed, try manually opening the fuel rack to see if it will pick up.  If it does, then most likely your culprit is the governor mechanism.

This was tried already. Thanks
Manually opening the fuel rack and the engine picks up.
I know it's something with the governor, not an engine problem.
I doubt it is just a spring issue, Will check the weight pins and let you know.
Is it possible the weights are not well balanced?

Cheers!