Suffolk 14s mower won't idle

[paul243]

My Suffolk 14s mower(1996 model),is now running well but wont tick over ,it runs at high revs but won't "throttle down". I've stripped and cleaned the Delorto carb,new plug,adjusted and lubricated all the linkages on the throttle.The cutting cassette is removed for sharpening,will this have any influence on the idle? Not sure about the positioning of the spring connecting the cable to the carb.
Any suggestions welcome!
Thanks

 

[Mursal]

The spring will make a difference, if you disconnect the spring and cable can you control engine speed by moving the butterfly linkage by hand? There is a screw jet (usually) on the side of the carb for adjustment? And its always good to have the air filter in place while adjusting.

 

[Burnerman]

If the engine just cuts out at low speed then its a pilot jet obstruction in the carburettor......could you possibly post a pic of the carb itself?
John

 

[paul243]

The spring will make a difference, if you disconnect the spring and cable can you control engine speed by moving the butterfly linkage by hand? There is a screw jet (usually) on the side of the carb for adjustment? And its always good to have the air filter in place while adjusting.

Thanks
Only have a mixture screw and throttle screw (which I've backed off).air filter is in and new.Will run the engine without the cable link off and advise,need to get a new plug today.

 

[paul243]

If the engine just cuts out at low speed then its a pilot jet obstruction in the carburettor......could you possibly post a pic of the carb itself?
John

Thanks
The engine doesn't cut out,it just won't slow to idle from full revs.
How do I post a picture?

 

[paul243]

Mursal
Sorry
Typing error!,should read "will run the engine without the throttle link attached"

 

[Burnerman]

If the engine won't return to idle, look for bent / incorrectly fitted throttle rods from the governor or the throttle stop screw (external / spring loaded) has been turned in too far.
John

 

[paul243]

If the engine won't return to idle, look for bent / incorrectly fitted throttle rods from the governor or the throttle stop screw (external / spring loaded) has been turned in too far.
John

Thanks John
Will try all the holes on the governor,throttle screw is backed off fully. Should the linkage spring be slack?
Can anyone tell me how to upload photos to my post?

 

[paul243]

Untitled

• paul243
• 11 Feb 2013
• 1

Untitled

• paul243
• 11 Feb 2013
• 1

See if this works!
Any help?

 

[Mursal]

You could try revving hard and just pull the choke, any blockage in a jet might just get sucked clean.
Would you have an air leak in the inlet manifold, bad gasket/crack?

 

[Burnerman]

Nice pics
I have to say, that linkage looks ok, but is there any possibility of the throttle rod locating in the other hole? Purely a guess.
When the engine is stopped, the governor should hold the carb throttle on nearly full.
Have you checked the pilot jet setting? I think its in the carb casting, opposite to the fuel inlet. It should be 1 1/4 turns out from fully in.
John

 

[kbdiy]

An engine running away like this is usually the sign of an air leak in the inlet somewhere. Have you checked for leaks/secure fixing of the carb and manifold?