Massey Ferguson 135

Hello,
I have a 1972 Massey Ferguson 135, Perkins 3 cylinder, gas.. Been a great tractor. Last summer while bush hogging I ran it out of gas and my problems started. I got it started back up but it ran terrible. Since then gas tank has been took off, sediment bowl replaced, new cap, rotor, points, condenser, plugs, plug wires, coil, and probably more stuff I am forgetting. Most of this was done at a shop when I gave up. Just got it back last week. Been with the mechanic all winter in his garage.He delivered it, drove it off the trailer and back in my barn. When I got home I went out and started it up and it purred like a kitten. I never drove it. That was 2 weeks ago. Last Sunday I went out and changed the oil and started it up to check for leaks. Started right up and idled fine. I thought I would take it for a drive and it ran like crap. It has no power, I cannot get the RPMs up, and it backfires like crazy.I am about to my wits end and spent quite a bit of money so far. Any suggestions would be greatly appreciated. Me and the mechanic who worked on it are scratching our heads.

My guess would be a sticking valve, I'm not an expert by no means lol

Once again, I see a prime example of the most expensive way to fix a problem - the shotgun approach.

Start here...
Diagnosis is your friend. Take off the distributor cap and check the shaft for side to side play. Bad bushings in the distributor are a common cause of the problem you describe. Note that I said CHECK, not REPLACE.
Next, check the fuel system for sufficient fuel flow. Another common cause of this problem is something in the tank floating around and randomly covering the fuel outlet thus restricting fuel flow and causing a lack of power. Junk in the carburetor bowl can also be a problem.
Check for any vacuum leaks.
If there is a vacuum advance on the distributor, check it for a ruptured diaphragm.

These engines are simply NOT all that complicated. Simple tools like a dwell meter, a timing light, and a voltmeter will help greatly. A manual will also help.

I don't see any mention of cleaning the carburetor. By coincidence the plugs or points or something else ignition related could have failed at the same time as running out of gas but I'll put my money on the fuel system being the problem.

Clean the carb as already suggested. I worked on an older MF a while back that was acting very simalar. Cleaned the gas tank, fuel filter, new lines, cleaned carb, and put some new points in. Drove it back to the mans house instead of trailering...

The backfiring, are you talking about exhaust backfire?

If so, that is usually a sign of intermittent ignition problems, loss of spark, weak spark, or erratic spark. Todays aftermarket points and condensers are known to be bad out of the box. Could also be a weak or wrong coil, bad electrical connection, even a bad ignition switch.

Backfiring out the carb?

This can be lean mixture (try partial choke), retarded ignition timing, stuck centrifugal advance, cross firing (wet distributor cap, weak plug wires), flat cam, bent pushrod, other valve problems.

As for the fuel system, has an inline fuel filter been added? That can be too much restriction for a gravity flow system. The fuel line should be steel, routed as directly down hill to the carb as possible, as far from the exhaust as possible. There is a drain plug in the bottom of the carb. With the fuel valve on, remove the plug, catch the fuel in a clean glass. The flow should start as a full stream, then slow to a trickle as the bowl empties. The flow should remain a trickle, not slow to a drip or stop. Some carbs have a second filter screen in the inlet fitting before the needle valve. Look at what was caught in the glass, if there is any contaminate, the same will be in the carb. It may need to be disassembled and cleaned, a simple job, probably won't need a kit if you can save the gasket.

Could it be cross firing in the distributor cap? Maybe carbon tracks or damp inside?

My 550 Oliver started backfiring - turned out to be point gap to small - barely opening.

I have seen a bad condenser act like a fuel problem. Stan

I agree with jimg.-sounds like no diagnosis was made.But when you ran out of gas,and refilled it, dirt in the bottom of the tank probably got stirred up,and,especially if you restarted it right away,some of that stirred up dirt got drawn into the carb,and is either blocking the main jet,or maybe an inlet to carb filter.If there is a plug in the bottom of fuel bowl on the carb,remove and see if you have a steady flow of gas(a stream almost as big as the line). If you do,then the problem is in the carb main jet or a passage way inside.If not,pull the line off the carb and check flow.If good,it is in the needle and seat or there is an inlet filter screen in the carb that is stopped up.If no/poor flow then then the line from tank is stopped up.This all presumes the tune up was done correctly,which since it idles smooth it is probably ok.It will back fire from a lean(starving for fuel) condition.Mark