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

 

[okiecraig]

Let's resurrect this one. Thought I had fixed problem by tightening throttle linkage several years ago but it happened as described above again yesterday. Threw it into neutral and used fuel shutoff to kill engine. WHen I tried to restart it acted like air in system from overrun. So i went to bleed fuel system and broke off upper bleeder screw. Now diesel fuel leaking from broken upper bleeder screw location. What do i need to do to fix broken screw?

 

[shona13]

If you are talking about the small bleed screw with the pointed end (5/16 a/f)wrench remove the ""seat"" ,the part that it screws into and fit a short setscrew with the correct thread,5/16"UNF x MAXIMUM 1 INCH LONG .
Bleed the pump that is pump the primer on the right hand side untill ALL the air has been removed ,best to pump for 30 seconds after the fuel starts to come out of the bleed hole just to make sure all the air is out ,fit the temporary setscrew while pumping so that air does not get in to the pump and GENTLY tighten, make sure the copper sealing washer is fitted under the head of the setscrew ,undo ANY injector pipe ,pick one that is easy to get to ,undo say a half turn then crank the engine with the hand throttle set at say 1/4 open engine stop knob in and when the engine starts tighten the injector pipe up ,Note": fuel at high pressure can penetrate the skin ,either shut the engine of and tighten the pipe or be carefull when tightening it up when running, not you, The Engine .
Any Diesel fuel injection repair shop will be able to supply you with the complete bleed valve and seat.
Happy days.
Hutch.

 

[shona13]

Another thought after reading ALL of your replies.
I would either remove the Injector pump, Or have it removed by a competent fitter and have the pump serviced, I am not sure when you say the tractor engine speed increases does it rev above the maximum on the tractormeter ,should be around 2200 /2300 rpm if so, I would not start it until the pump has been checked, if you do over rev the engine there is a very real chance that you could do some serious damage.
Hutch.

 

[PatrickS2222]

As previously stated: Renew fuel filters and monitor progress regarding unexplained increases in engine speed. You may not need to do any further work.

Regarding the broken bleeder screw: Did it break while you were trying to loosen it, or whilst retightening it? They only require a very light tightening. As Shona said ... any diesel shop (or ask PumpGuy nicely) and renew the complete bleeder.

 

[thepumpguysc]

I have them.. send me a prvt msg w/ your address..
U said, the upper bleed screw.. u mean the 1 on the top cover.??

 

[okiecraig]

I have them.. send me a prvt msg w/ your address..
U said, the upper bleed screw.. u mean the 1 on the top cover.??

I will post photo of broken piece and location in a few hours. thanks for all the help so far

.

 

[okiecraig]

Broke off while I was re-tightening.......

 

[thepumpguysc]

Email sent.

 

[chopitrakeit]

This the screw? CAV* Lucas* Roto Diesel* – Top Cover bleed screw and washer 7123-351A | eBay

 

[WilliamTO-35]

I don't mean to high jack your thread, but as a few words of warning I recall this surprise event. I was pulling my TO-35 up to my (closed ) garage door , and I pushed in the clutch. The tractor just kept going, and I crashed my front loader through the garage door. Apparently, some oil leaking from the engine rear seal had contaminated the clutch surfaces, and caused the clutch to stick . Adjusting the clutch lever didn't work . I sprayed some solvent up through the access hole, and it dissolved the gunk. It hasn't done that again during the last 20 years, but I'm still a little nervous when I push on the clutch pedal. Pulling the shift lever out of gear would have been the quick way to stop the tractor, but I didn't think of that in time. My point in relating this story is that engines ( and clutches) that don't respond as they should, such as yours, can be a real hazard ! ( And to complicate the event, my bush hog mower was still engaged, and helped to push the tractor forward. I've since installed a one-way clutch overrun attachment on the pto to prevent the mower from pushing me forward.)