MF 6485 stuck on full revs

[gooseman]

Hi Everyone, hope you are all well. Recently purchased a 2009 MF6485 2500hrs. Friend used tractor for an hour, on returning the engine was at full revs and whatever we do we cant slow it down. Engine is running fine and sounds sweet. When we actuate the A/B switch it is indicated on the screen but makes no difference to the revs. +/- switch also makes no difference. When engine is stopped and restarted the engine continues to fully rev. Could it be a potentiometer issue? Any help would be appreciated. Keep safe everyone.

 

[Lofty1984]

Not a stone or something jamming the foot throttle open in the cab ?

 

[gooseman]

Can't see anything, although it is dark. Not sure maybe needs a calibration. Not sure exactly how this fault first started as I cant get hold of the lad that was using it. Maybe needs calibration, but not sure what has happened to make it need one.

 

[daveydiesel1]

Have u tried to recalibrate the throttle. Hold the diff lock button for a few seconds til she beeps and a cog appears on ur screen then put the throttle down fully and release it again and let go of the diff lock button. Worth a try

 

[Nearly]

@masseybreaker

 

[gooseman]

Have u tried to recalibrate the throttle. Hold the diff lock button for a few seconds til she beeps and a cog appears on ur screen then put the throttle down fully and release it again and let go of the diff lock button. Worth a try

Just tried this... No difference. Give me my 699 anyday

 

[RmfJ]

Pull the hand throttle back!

 

[gooseman]

Pull the hand throttle back!

Ha ha Cheers mate... !!!
unfortunately tried that

 

[Db990]

Check the plastic linkage hasn’t fallen off the foot throttle potentiometer

 

[gooseman]

Check the plastic linkage hasn’t fallen off the foot throttle potentiometer

Will have a look tomorrow. Thank you.

 

[jh.]

Used to use a 58plate 6480 that sometimes went mental after washing for a few hours . It wouldn't run flat out all the time but revs would jump about with presets flashing on and off and changing them itself . Once it dried itself out it was fine until the next pressure washing

 

[gooseman]

Used to use a 58plate 6480 that sometimes went mental after washing for a few hours . It wouldn't run flat out all the time but revs would jump about with presets flashing on and off and changing them itself . Once it dried itself out it was fine until the next pressure washing

Thanks for that. This hasn't had a wash in a while to be honest.

 

[bobajob]

I know your trying to get it fixed - I don't like to think of a cold engine going straight to flat out, especially in this cold weather and cold oils etc.

 

[Rob Holmes]

Our 6480 does the same,
It’s the pin in potentiometer in foot throttle that comes out, take cover off pedal and will be there, 5 min job

 

[gooseman]

I know your trying to get it fixed - I don't like to think of a cold engine going straight to flat out, especially in this cold weather and cold oils etc.

Yes I know what you mean. I must admit when I finished yesterday the last thing I thought of was just that point. We are always very careful not to over rev cold engines. Thanks for you concern. Keep safe buddy.

 

[gooseman]

Our 6480 does the same,
It’s the pin in potentiometer in foot throttle that comes out, take cover off pedal and will be there, 5 min job

Thanks mate. Going straight to that once I've shuvved me Sunday morning toast down my throat Your reply is much appreciated. Will post straight back when I've looked. Keep safe

 

[bobajob]

Yes I know what you mean. I must admit when I finished yesterday the last thing I thought of was just that point. We are always very careful not to over rev cold engines. Thanks for you concern. Keep safe buddy.

Yeah I know, not trying to be a smart arse here. Things are never ideal are they . Hope you can get it fixed.

 

[gooseman]

Yeah I know, not trying to be a smart arse here. Things are never ideal are they . Hope you can get it fixed.

Never thought that for a second mate. Thank you.

 

[gooseman]

Our 6480 does the same,
It’s the pin in potentiometer in foot throttle that comes out, take cover off pedal and will be there, 5 min job

Our 6480 does the same,
It’s the pin in potentiometer in foot throttle that comes out, take cover off pedal and will be there, 5 min job

Yep you were 100% correct little "R" clip fell out or was pushed out by little stone and potentiometer actuator lever slipped off all going now. Thanks to everyone and Keep safe.