MF35 gas engine not running right. Help please!

DriverChad

New User
Hello All,
I have a 1960 MF35 with a Continental Z134 engine. About 3 weeks ago it started spitting and sputtering and not wanting to take gas unless the choke was 1/2 set, then it would run great. Since then I have done the following and it hasn't helped a bit.
1. Thoroughly cleaned and rebuilt carb, new jets, new float set at 1/4". Idle needle set at 3/4, power needle from 1-4 with no change.
2. Checked new manifold for air leaks and made sure it was torqued tight.
3. Cleaned Distributor, checked the weights and are functioning correctly, no play in the dist. replaced points, condenser, rotor button, coil, cap, and plugs. (wires are 4 months old).
4. Cleaned gas tank, replaced sediment bowl valve, replaced fuel line. ( have steady stream to carb.)
5. Ran compression check, ranges 120-130 psi between all cylinders. Checked valves (compressed air) no signs of leaking valves.
6. Rewired tractor in January.
7. Checked timing. Static 6* btdc and 28-30 at 2200 rpm.
None of this has corrected the problem and I am totally out of ideas. Please someone help and point me in the right direction. Any help would be greatly appreciated. Thanks, Chad
 
Normally if it runs better with choke 1/2 out then the carb is still stopped up,

If you have done all the other work as you have said, then that is where I would start,
Did you soak the carb body in cleaner?

Where did you buy rebuild kit?
Should be a quality kit from MF or Napa

I had to install a metal free flow inline gas filter between the cutoff valve and carb before I finally got my tractor carb to stay clean and running
right,
Have you throughly cleaned your fuel transfer tanks all it takes is adding fuel from a dirt gas container and all your problems start again,

You have down loaded the carb rebuild and adjustment data for your carb,
What carb number do you have?
 
Maxwell99,
No, I did not soak the carb, just used aerosol type carb cleaner and compressed air. I bought the kit from Yesterdays Tractor. Yes, all my gas cans are clean. I have a marvel schebler TSXU 834. I just tore it apart again and have it soaking now. Will let you know tomorrow evening how it turns out. Thank You
 
When these things are 50 or 60 years, they got to fly by the seat of their pants. Don't adjust a carb or linkage by the book, the book was written for brand new machines or atleast all new parts in good condition. Get someone to stay on the seat, keep it running however possible while you turn the mix needle and wiggle the linkage till you find something that responds in the right direction. Also, I twist the distributor cap to the point it roars wide open, then find a sweet spot where it starts fine, and slows to idle without spuddering too. I don't look at numbers, I listen for results. You just got to keep experimenting.
BTW, remove the air cleaner hose while you try stuff. Then readjust the needle If you need to. You didn't mention your air cleaner???
 
Tony,
I replaced the air cleaner element and oil in January. I'm like you, I find the "sweet spot" when tuning something. I just set everything to factory specs for a starting point, then fine tune from there. Thanks for your response, Chad
 
Maxwell99,
I soaked the carb over night and got it squeaky clean. The tractor is running better, but still not back to the way it was before all this started. Think I'm going to replace the plug wires tomorrow since that's the only thing I haven't done recently.
 
Reading what all you've tried my guess is an air leak around the throttle butterfly, try turning the small screw all the way in.
 
I had the same problem on a MF65. The "O" ring on the mixture screw in the bottom of the carb was worn out.
It allowed the screw to shake loose and move over time. A new "O" ring...15 cents...fixed it.
Not sure you have the same carb.
Moisture in the gas will do the same thing.
 
"be sure to buy copper core plug wires,"

not the type used on cars with resistor cores (for good radio reception).

again, not an area to go cheap,

I use autolite 3116 plugs in my tractor
have had good luck with them,

but many purist no longer use autolite as they have moved manufacturing to china and the quality of my next plugs may be less, but so far so good,
 
I put some Accel copper core wires on it, still didn't help it. Guess I'll start over from the beginning and made sure I did not miss anything. Thanks everybody for your input. Chad
 
OK, I know the carb is really clean, soaked it in carb cleaner, acetone, and vinegar. Cleaned all the passages with pipe cleaners, and needles in the passages to small for the pipe cleaners. I have good flow of gas thru the needle valve, but still not able to get the mixture rich enough for the tractor to run right with out the choke 1/2-3/4 set. The carb on the tractor is a marvel schebler TSXU-834, everything I've seen says this tractor should have a TSX-605/683. Do you all think this could be the problem? just want to get your all's input befor I spend several hundred dollars on a new carb. Thanks, Chad
 
It ran before with this carb it should run now. The other possibility of, to lean to run with out the choke, could be excessive air leaks around the throttle shafts or intake gasket matting surfaces of the intake manifold. You can usually find them by lightly spraying some starting fluid around those areas and listening for the change in the engine, maybe worth a try.
 

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