Punsen Govenor arm

[Fiddler]

Hi Guys,
I removed the cable, control arm and springs from the govenor arm of my Punsen whilst I mounted it in the frame.
For those familiar it looks identical to the 10hp yanclone govenors posted on the yahoo pictures.
Now that the engines in, I want to start work on a throttle cable but think I've got a problem.
The govenor arm will now only twist a couple of mm's left to right. It appears almost stuck in stall/low idle position. It will not turn anywhere near the stop/buffer by hand.
What have I done?
Should I be able to turn it to the buffer by hand?
As there appears nothing that can impede its movement on the outside, does this mean I have to have the side of the engine off?
If I need to have the engine side off will I need a new gasket before reassembly?
What am I looking for when in there?
Many thanks in advance.

[Diesel Dave]

Fiddler,

Are you attempting to do away with the spring controls? 'cos you can't.

The outer spring arm should have a cable mounting, all this arm does is to provide spring pull pressure against the regulator arm.

The regulator has a centrifugal element (inside the casing) to control the motor speed, the amount of pull you place against the centrifugal element controls the speed.

Think of your throttle as a ships telegraph, you are sendning a request for revolutions to the engine where the regulator is the ships engineer who is in control of the engine.

Hope this helps
Dave

[Anorak_ian]

Dave, this sounds very odd, please tell me this doesn't go for all type of engines Maybe a mod could be made for this?

[Diesel Dave]

Pretty much all diesel govenors work on the principal of spring tension against centrifigal forces.

If you were to attempt direct control of the 'rack' (injection volume) you would find the motor pretty uncontrollable, a minor movement will result in the motor attempting to race away.

However nothings impossible, if you pull the injector pump you will see the control arm. You will need to rig up a cable control inside the casings - but ah! you have two so a bit more complication...... Be careful of the gearing ratio from the twistgrip or you will be riding a bucking bronco.

Best of luck.
Dave

[Fiddler]

Sorry dont think I made myself very clear.
I pulled the assembly and springs apart for two reasons. Firstly to see how a new throttle cable attached. Secondly because they appeared vunerable with the cover off, which I wanted out of the way whilst i wrestled it in and out of the frame making measurements ect.
I fully understand that its essential to put it all back as was. Yahoo's archives were invaluable in researching how it worked.
Whilst replacing the springs and control arm though I noticed that the bottom arm(regulator) appeared stuck. It has about 2mm of movement left to right. I imagined that it ought to move a lot further before coming to rest on the buffer, possible moving 15mm or so before doing so.
Either I have a problem and it is stuck or my understanding of its operation isnt as good as I'd hoped.
Help in clearing this up most appreciated.
Thanks

[Diesel Dave]

Ahh.

Yup the arm won't move without the motor running, the internal spring/bob weights will stop this happening.

Dave

[Fiddler]

Thanks mate, thought that was a possibility but clearly got confused somewhere.
Help most appreciated.