pneumatic governor diaphram

[kiwiland dexta]

After a bit of 'tractor therapy' going round in diminishing circles ahead of a mower I noticed the engine revs didn't drop much when I stopped. Did a forum search and as a result checked the diaphram: holes. The old one is stuck in, for now it can stay there until I find a replacement.

Has anyone had to buy one of these lately? As far as I can gather there's only one size (pneumatic governed Simms) Previous posts suggested they are quite costly- any tricks there?

The old one was also quite wet - I presume this is a result of the holes?

Interesting to hear your thoughts.

Regards, Derek.

[justjamiefarming]

I have just replaced mine a couple of weeks ago.

I changed the Diaphragm :- £34, along with the diaphragm spring :- £25.

Both from Forge Services in the uk.

Very easy fix and solved all earratic idling problems. Ticks over as sweet as a nut now!

[Chris Ivin]

Did you take the pump off to change the diaphragm? I have opened up the governor housing but the split pin looks difficult to get at.

[PghBill]

Chris,
I changed mine without removing the pump. A slight bit tedious but much easier than removing the pump.

[Chris Ivin]

I'll have another look tomorrow.

I picked up some new spectacles yesterday so I might be able to see what is going on now!!!!

[kiwiland dexta]

Did the job without removing the pump too, got mine from Dunlop's, local dealers tried to help but looked at me sideways when I mentioned what I wanted! The job was a fiddle, was most worried I'd puncture the diaphram trying to fit it but inthe end it worked out fine, just make sure the small protrusion on the diaphram outer is lined up with the recess in the housing before you tighten things!

[Chris Ivin]

Just got back from a few days away with my good lady and had another look at the governor diaphragm.

I only have about 3/8 inch gap through which to look for the diaphragm split pin. It has just struck me that perhaps it is supposed to pull out further than that. I do not know much about injector pumps but I am guessing that the diaphragm is attached the injector pump rack, could mine be sticking Should it be coming out further than this

[Chris Ivin]

I have managed to crack it at last A bit like key hole surgery though.

For those who have not changed a governor diaphragm before:

There is only a very small gap between the diaphragm(when pulled out of its seat) and the injector pump housing to access the split pin. I found I had to remove the exhaust manifold to be able to get access to the split pin that secures the diaphragm in place (the split pin is on the cylinder block side of the mounting shaft). Long nosed pliers were essential, bent long nosed pliers would have been better. Good eyesight or a decent pair of spectacles are essential!!!