Massey 135 engine mystery

[okiecraig]

OK, guys, help me out for i get killed! Was mowing today with Massey 135 (40 Hp Perkins diesel) when the throttle suddenly increased and would not respond. I threw in the clutch, took it out of gear, jumped off and manually decreased the throttle to idle. I waited to see what would happen and sure enough, after 5-7 seconds, it started increasing again on its own.

I am mystified. Have had this wonderful old tractor for 8 years and never had a lick of trouble.

Ideas???


Thanks...

 

[okiecraig]

ok, may have lost compensating governor spring...................anybody got a picture of one?

 

[murphy1244]

Go to this site and sign in as guest. Pick your make and model and your in.AGCO Parts Books

 

[okiecraig]

thanks, Murph

 

[okiecraig]

Mystery deepens......start tractor this morning, throttle lever worked fine. Guess i have more diagnostic work to do to get it to repeat. So, I will operate with bush hog going like yesterday and see if it starts over-revving when it gets hot..........

 

[The kid]

Debris could have gotten the linkage if it doesn't happen again. Throttle and Governor linkage are connected to each other.

 

[shona13]

G'day okiecraig.
Just check this simple thing first .
Standing on the left hand side of the tractor engine stopped operate the hand throttle both directions, fully open and returned to idle ,do this a few times and make sure that when the throttle lever is returned to the idle position that it does actually hit the idle stop screw on the pump.
If the throttle linkage is adjusted properly it will work as intended but over the years of use things wear ,adjusting nuts loosen of and eventually the throttle does not work properly,the most common FIX is to fit a return spring from the throttle arm to the timing case at the front of the engine ,your engine may have one of these springs fitted and it has broken or has come adrift ,easy check and fix.
happy Days.
Hutch.

 

[okiecraig]

Grrrrrrr.....Thought I had figured it out but no! Bushhogged yesterday for 6 hours and no problems; then, just as I pulled up next to the shop, the engine raced uncontrollably again.

If it were getting low on fuel, would that cause the sudden throttle increase?

Thanks for comments so far....any other ideas for me?

 

[Dieseltech]

Does the tractor have a Thermostart intake heater for cold starts? It may be bad, allowing fuel into engine if bad. Injection pump may need repair also, but most I see don't have this problem. When it runs away, can you shut it down when you pull the stop knob?

 

[Timer]

I had a similar problem 4 or 5 years ago on my UK 135 Diesel. It would rev up then shut down. Tow it back to shop, go through the bleeding process, it would start and run for a few weeks then the same routine again. Finally after puting up with this for a year, I had some time to deal with it. Removed the fuel tank and heard somethink rolling around inside. After much shaking I retrieved a piece off the pickup. Not broken just came off. Replace the tank after cleaning and tried running again. Ran for an over week or so then started again. Went to my MF dealer and he suggested replacing the filters which I had done the year before and he also suggested the fuel pump. Ok, installed the fuel pump and knock on wood she is still running and she is just waiting for a good winter of blowing snow.

Timer