Oil & Fuel MF 135 zenith carb problems

   / MF 135 zenith carb problems #1  

beemtoes

New member
Joined
Jul 11, 2010
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1
Tractor
MF 135
tractor runs only with choke pulled all the way out, pretty rough but I can do most jobs with it that way, cuts out then comes back. Fuel filter is clean and ran some spray in carb cleaner. Reluctant to start messing with adjustment knobs. Also on this carb there is a wire that is connected to main adjustment. I was thinking of running some gas additive carb cleaner next. If no fix then a rebuild kit for carb .I have had this tractor since 96 and has been tuned 3 months ago . any quick fixes?
 
   / MF 135 zenith carb problems #2  
Did you do the tune-up yourself or have it done? I had a similar problem once and it was a linkage problem, check to make sure all the rods / spring etc are free from obstuction and operating properly.
 
   / MF 135 zenith carb problems #3  
I have the same promblem rebuilt carb,new fuel filter, sediment bowl clear,tank clean , new plugs,wires,coil, points distr. cap and button. runs sometimes fine then want run without choke pulled and thats at idle what would i do? I have the zenith none adjustable carb and no wires or fuel shutoff on carb.
 
   / MF 135 zenith carb problems #4  
I'm having the same issues. Have you found a fix or did you buy a new carburator.
 
   / MF 135 zenith carb problems #5  
Check for fuel flow to carb. If good there, remove the elbow going into the carb. were the fuel line attaches. The should be a mesh screen/filter, attached to the el. Check for sediment that may have been caught in there. Some spray carb. or brake cleaner will flush it out. A shot of compressed air to finish it up.

If there is no screen/filter attached to the el, remove the bowl from the carb. More then likely sediment in there. If it's there, there's a good possibility that the discharge nozzle (brass tube sticking up on abut a 45º angle) has some blockage. Remove it and check for blockage, especially in the really small cross drilled holes towards the bottom end. Also remove the jets, and spray carb. cleaner through them. A single wire from a wire brush, or a strand of wire from say 10 or 12 ga. automotive type wire makes a good cleaner.

The crappy gas they make now a days w/ethanol, seems to make crud in the fuel tanks, due to drawing moisture. 99% of the time I have problems with my gasser's, that's the problem. Once I get the system clean, I dose them with Seafoam, and try to remember to give them a dose several times a year. Especially in the late fall, and in the late winter, very early spring, when everything around here seems to go through the spring sweat. Up here, when it's been in the upper 20's to lower 30's, then gets to 60º or so, everything beads up with moisture, like they are sweating.
 
   / MF 135 zenith carb problems #6  
if you have a good flow of gas disconnecting the line from the sediment bowl at the tank cutoff you can rule out the internal screen filter inside the tank. Sounds like the main jet is clogged. Check the flow at the tank and work your way to the carb. Is this on a Perkins?
 
   / MF 135 zenith carb problems #8  
The gas tank is gravity fed to the carb. I personally would drain the tank and take a looksee inside. There could be a lot trash on the bottom clogging or restricting the flow. There is a fine mesh screen filter that stands up inside the tank to prevent debris into the carb. It can get gummed up and slow the flow. Carbs are not hard to rebuild if needed. If it was running good before more than likely your carb adjustment are correct. When you remove the carb, make note on how many turns it take to screw them all the way in. If the tank has crud in it. You can unscrew the sediment cutoff bowl usually near the battery on the bottom of the tank. It just screws into the tank and sealed with some Teflon tape. Once you have the bowl off the tank, you can attach a rag to a coat hanger wire saturated with some good fuel cleaner and swab the bottom near the bowl connection point. If your seeing a lot of debris will warrant a good tank rinsing after loosening it up scrubbing the bottom. If this doesn't solve your problem you'll at least have a clean tank.
 
   / MF 135 zenith carb problems #9  
Hey Kid, good to see you posting.:):thumbsup:
 
   / MF 135 zenith carb problems #10  
I note you said you had a fuel filter...if its more than the screen inside the carb, get rid of it...have a straight run from the tank to the carb...you obviously have a "fuel starving" issue if you need to run it with the choke. Any slowdown of the fuel from the tank to the carb may cause your issue. BobG in VA
 
 
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