Getting a MF 135 going again ...

[dbwinva]

Hello all. Just joined. My father bought this tractor used (it was ~2 yrs old at that time), then he used it for ages ... when he passed away my cousin used it another ~5 years until his health got to where he couldn't use it any more. It has sat for ~3 years and now I'm going to try and get it going again.

It has the 4 cylinder gas engine and around 2800 hours on it.

The first step was a new battery, and syphoned out the old gas, put in fresh gas, then turned on the gas valve by the sediment bowl thing, and gave it a try.

It started and ran for ~2 minutes and died. I tried to start it several more times with no luck. Went from super happy and "what a tractor!" to rats, what's wrong real fast.

I decided to give it a break and try again later ... when I came back (about 20 minutes) gas was dripping out of the carburetor, I had left the gas valve on ... so I turned the gas valve off, went away for ~10 minutes, came back and it was still dripping gas from the carb.

So 2 odd things there ... shouldn't the carb floats stop the flow of gas? Or do I need to always turn that fuel valve on/off? And second, why did it keep dripping long after I turned the gas valve off?

So now I'm a bit worried I have gas in the cylinders/engine. I pulled the dip stick, it does have a very strong gas smell.

For the carb, I was doing some searches and found new ones on Amazon for $65. Not sure if I can fit the carb leak by just pulling it apart and trying to clean things up.

I'm thinking next steps:
- sort out carb leaking and how to fix that. Just buy a new carb? Pull apart and clean out?
- sort out gas valve, does it not really stop the flow. Is it a bit messed up too.
- once my leak/drip is sorted then:
= pull spark plugs and rotate engine a few times in case there is gas in the cylinders
= change oil and oil filter
and try to start it again.

And tips/hints greatly appreciated. Thanks.

 

[5030]

The 65 buck carbs on Amazon are Chineseum junk. Replace the gas lines and shutoff and remove and clean the carb in Berryman's B12 chem tool and reassemble it making note of the jet screw settings to start with. Bet the gas tank is loaded with sludge, the gas lines rotted and the carb loaded with crud too.

If you cannot do it, have someone who can.

 

[jaxs]

Like 5030 said don't buy the new carbs,they are junk and the origional will last a life time, kits are inexpensive and rebuild is simple.
Gas can't enter engine until it fill's intake manifold (very unlikly for an updraft carb). I would drain plug from carb bowl to see if valve works and line is open. Before pulling glass bowl from valve buy a new screen and gasket. TSC normally carry's them as well as carb rebuild kits.

 

[dbwinva]

Great info, thanks. I figured the $65 new carb couldn't be real!

I am familiar with motorcycles and have worked on them for many years so hopefully I can get this sorted out.

Was the 4 cylinder gas engine sort of rare? The manuals I have found online and looking at tractors for sale, seems the 3 cylinder Perkins gas engine was way more common.

Does the 3 cylinder and 4 cylinder have the same carb?

 

[jaxs]

The 135 was a popular tractor and all the gas models I've seen were 4 cylinder. I'm not sure if they share carbs. Being familar with four stroke motorcycle engines put's you out front when it come's to troubleshooting tractors. Systematic process of elimination is how i approach a no start issue. That is to say I don't replace parts unless they are bad. Many people will replace plugs,points,condenser,rotar,plug wires,dist cap and fuel filter if engine fails to start or run's poorly. It does sound like the needle and seat aren't sealing but a stuck float acts the same way. I would remove the air intake hose from carb,drain and refill bowl a couple times before tearing into carb. Having set up a while,a little "exercise"may very well be all that's needed to get float and needle working again. I'm sure you already know this but it can't be overempasized. Having a fire extingusher handy is highly reccomended. When draining fuel,catch it and set aside well away from where you are working. The danger lies in having gas on carb,the ground and YOU ignite if engine backfires through carb. Don't rule out ignition and chase fuel,test and eliminate one thing at a time.

 

[etpm]

I dunno anything about your particular tractor but do know a lot about working on old spark ignition engines. Since it ran and then stopped you know spark is possible. You don't know if it still has spark. Since the carb was dripping fuel I would check spark first. If it has no spark of a weak spark then of course address that first. If it has a good spark then check the carb. If a piece of dirt is holding the float valve open it is entirely possible that another piece of dirt is blocking the main jet. It is also possible that the engine is flooding out because the float valve is stuck open. There are lots of carb cleaners in spray cans available so pick your favorite if you think the carb needs cleaning out, which it most likely does. When spraying whatever cleaner you use try to get it into the fuel passages the opposite direction of the normal fuel flow. If there is a dirt particle blocking a passage it will come out easier the way it went in. If needle valves need to be removed my method is to make a mark on the carb body that lines up with the screwdriver slot on the needle valve. I also make another mark on the needle valve at the end of the screwdriver slot that lines up with the mark on the carb body. Then I turn the needle valve in, counting the turns, until it gently bottoms out. I write the number of turns down. Then I remove the needle valve. I'm sure you already know all this, seeing as how you have experience working on motorcycles. But a reminder might help.
Cheers,Eric

 

[dbwinva]

Here are some pictures of the tractor:

 

[dbwinva]

 

[dbwinva]

Got it running!!

Steps I did:
- pulled the bottom screw from the carb and all the gas that came out looked good, no junk in it
- turn on the valve by the sediment thing and just 1/4 turn of that and gas came out the carb, closed that valve, and fuel flow stopped, so that is working well
- pulled off the sediment bowl and there was no junk in there, put that back on
- pulled the 4 spark plugs out
= they looked in really good shape! So maybe my cousin/dad did do some maintenance on the tractor
= turned the engine over by hand (well, by wrench) with plugs out, just to make sure I didn't have gas in the cylinders. Sounds like that was unlikely, but I wanted to check the plugs anyway. Did not notice any gas coming out.
= put the plugs back in. The plug wires seem to be in excellent shape, very flexible, no cracks, rubber feels new
- cleaned up the battery terminals a bit and made sure they were on tight

So ... turned on the gas valve, choke, and 1/4 throttle, and it fired right up!!

Pushed choke off, rev'ing real high, pushed throttle fully closed, still running around 1200 rpms.

As it warmed up, seemed the oil pressure was good, saw the water temp coming up, gas gauge seems to work, hour meter was working.

For the high idle, I tried adjusted the screw on the carb and that made zero difference.

On the linkage, if I pulled the one linkage back towards the carb (it moved maybe 1/4") the rpms would drop to around 900-1000.


Next steps:
- clean up those throttle linkage joints a bit, see if they are sticky
- see if I can figure out how the heck that all works! Kind of like a big lawnmower! I like the motorcycle, cable to carb slide, nothing in the way approach.
- change the oil and filter. Oil is full level, but smells very gas like, and seems a bit thin.
- I remember my father put the low pipe on it. It came with the pipe that went straight up. But that low pipe has nothing holding it up! Seems there should be some sort of hanger/support on it. I've looked at pictures online and seen others with nothing there too, but that just seems odd to me.
- At some point I need to check tire pressure and make sure they are not leaking down
- And then wash it up

 

[etpm]

View attachment 714034

That carb looks just like the carb on my Ford 9N tractor. They are easy to work on. Because of the way the carb is made it is a bit of a pain to make a new float bowl gasket. But it can be done. My Ford has a home made gasket in it right now so if you want you can buy a roll of gasket material and make your own if you want to work on the carb right away. But check for spark before working on the fuel system.
Eric