Set up information for carb / throttle cable.

[ipbr21054]

Where the governor arm is at present ie vertical then this must be where the butterfly is fully open. The governor arm can now only be moved to the left thus starting to rotate the quadrant arm thus closing butterfly & lowering revs.
When engine is running I can move the quadrant and bring the revs down.
This is a right pain as I see no reason at all why what’s happening is happening.
Maybe put something behind quadrant arm & it’s stop to force the butterfly closed a touch.
It’s a bodge but will stop butterfly being able to be fully open.

Does that sound like a fix or will that just create other issues.

Yesterday the lawn I did normally take just less than a tank of fuel. With the revs high & me running when using self propel I had to add more fuel before I finished.

 

[ipbr21054]

Just to also advise you.
I have another throttle lever of which is the same as what’s fitted. Looking at the length of this cable & the one fitted it’s slightly longer on the outer cable.

Does this help you at all or maybe test something.
Maybe it’s just longer as the mower it came from has a different length handle. Just putting this here to assist you.

 

[Burnerman]

I can't see how the throttle cable - which pulls a lever (third picture along) transfers this movement to the bell crank on the top of the carb?
John

 

[ipbr21054]

Do you need another photo from different angle ?

 

[ipbr21054]

With cable removed and I operate this lever I only see the choke butterfly move.
The butterfly further in doesn’t move.
Just for your info.

 

[Burnerman]

Thanks, I can see how the cable pulls the lever over a small arc, but how does that lever connect to the top part, which we are calling a bell crank or quadrant?
John

 

[ipbr21054]

The part what we call the quadrant and arrowed in photo I can see only moves when governor arm is moved.

 

[ipbr21054]

See here.
Governor arm

 

[lostinthelight]

Take the spring off and start it and see if revs drop

 

[ipbr21054]

Which spring would that be please ?

 

[Burnerman]

OK, things are a little clearer now.
Operating the throttle cable only controls the choke, correct? That's because the cable doesn't connect to anything else.
Therefore, the engine speed is purely controlled by the governor.
With the engine running, can you push the governor arm back at all.......sort of fighting you if you get my drift - and that could slow the engine up?
John

 

[ipbr21054]

OK, things are a little clearer now.
Operating the throttle cable only controls the choke, correct? That's because the cable doesn't connect to anything else.
Therefore, the engine speed is purely controlled by the governor.
With the engine running, can you push the governor arm back at all.......sort of fighting you if you get my drift - and that could slow the engine up?
John

At present the govnor arm is vertical so butterfly fully open.
It will not push to the right.
I will start the mower & see if the arm will then push to the left.

 

[Burnerman]

As you will gather, with the engine stopped, the governor system should hold the throttle open.
Once started, the governor reduces RPM to accommodate the throttle setting at the handlebar lever (but yours doesn't have this) so we need to
find out how to prevent the engine revving it's guts out.
(Many makes of mower have a fixed speed engine, and no throttle control so this isn't unique.)
John

 

[ipbr21054]

OK i agree / understand.
Just giving it a little time say 20 minutes before i wake people up.

Im happy to have it at a set rev range but at present ive lost 2 stonne running as self propell & high revs make the mower like an F1 car

I will reply back shortly.

Just a side note last night when it was running i did move that quadrant on top the carb using my finger & yes the revs come down as you would expect.

 

[lostinthelight]

Which spring would that be please ?

The only one I can see on top of the carb