Getting a MF 135 going again ...

jaxs · Sep 20, 2021

Way to go. Now put the old beast to work. I would bend a piece of metal to fit from a lower transmission/bell housing bolt over to pipe then clamp with a regular muffler U clamp. Brush could push on pipe and crack manifold.

5030 · Sep 21, 2021

The carb is a Marvel-Schibler, very common on old gassers and rebuilt kits are everywhere.

dbwinva · Sep 22, 2021

More progress ...

- changed the oil & filter
- changed the air filter
- adjusted the throttle linkage, got idle down from 1200 ish to 900 ish, still a bit high
- checked the hydraulic fluid level, it was right at full and looked really clean
- checked that the things in the back go up and down (sorry, not a tractor guy, the things that hold a plow)
- checked that the PTO spun when you turned it on
- drove it around in the yard!
- washed it. Mostly the red parts. It looks 3% better.

For the carb leak, seems if every time I stop the tractor I turn the fuel valve off over by the gas sediment tank, then the carb does not leak. I did forget that once and left it on like 10 minutes with the tractor off and it didn't leak.

New discovery, the full level sensor thing on the gas tank ... after driving it around for 15 minutes I looked it over and that area was kind of damp. So some gas is weeping out from that seal/gasket ... I assume there is a gasket under that.

Next steps:
- still need to sort out an exhaust hanger
- need to sort out the fuel level seeping/weeping
- need to study the carb linkage mechanism a bit more ... see if I can get the idle down to 750 ish. The carb screw might work now that the revs are lower.
- need to check tire pressure and make sure that is stable. I assume these tires are tubeless?
- need to decide on the looks and cleanliness. Could leave it as-is, call it patina. Or could try some sort of wax/cleaner
- oh, head lights don't work ... need to sort out if that is wiring or bulbs. Since both are out I'm guessing it is wiring.

At some point we will try to sell it. Probably advertise on facebook and craigslist.

redman135 · Sep 26, 2021

Observation: your left foot brake is on the floor. Probably just need a brake return spring.

Jerry/MT · Sep 26, 2021

dbwinva said:
More progress ...

- changed the oil & filter
- changed the air filter
- adjusted the throttle linkage, got idle down from 1200 ish to 900 ish, still a bit high
- checked the hydraulic fluid level, it was right at full and looked really clean
- checked that the things in the back go up and down (sorry, not a tractor guy, the things that hold a plow)
- checked that the PTO spun when you turned it on
- drove it around in the yard!
- washed it. Mostly the red parts. It looks 3% better.

For the carb leak, seems if every time I stop the tractor I turn the fuel valve off over by the gas sediment tank, then the carb does not leak. I did forget that once and left it on like 10 minutes with the tractor off and it didn't leak.

New discovery, the full level sensor thing on the gas tank ... after driving it around for 15 minutes I looked it over and that area was kind of damp. So some gas is weeping out from that seal/gasket ... I assume there is a gasket under that.

Next steps:
- still need to sort out an exhaust hanger
- need to sort out the fuel level seeping/weeping
- need to study the carb linkage mechanism a bit more ... see if I can get the idle down to 750 ish. The carb screw might work now that the revs are lower.
- need to check tire pressure and make sure that is stable. I assume these tires are tubeless?
- need to decide on the looks and cleanliness. Could leave it as-is, call it patina. Or could try some sort of wax/cleaner
- oh, head lights don't work ... need to sort out if that is wiring or bulbs. Since both are out I'm guessing it is wiring.

At some point we will try to sell it. Probably advertise on facebook and craigslist.

These old Marvel-Schebler carbs (yours maybe a Zenith or a Carter as they were also used) are notorious for being difficult to set the floats on. In many cases the float hinge is worn and the float can move laterally and hang up on the side of the bowl. A sharp rap with a wooden block will free it but a new set of floats and a new float pin might be a longer term solution. However many owner just turn off the fuel with the sediment bowl valve when thy are not using the tractor.

As far as idle speed adjust the idle air with the small screw on the side of the venturi section (M-S carb). Turning that screw counter clockwise increase the idle air (i.e leans the mixture). For the M-S Carb the nominal setting is 3/4 turn out from full in. Adjust the idle airflow so that the engine runs smoothly at 500-600 rpm and then set the idle speed to around 450 rpm if you can.
The large screw adjusts the power jet and the nominal setting is no less that 1 full turn out. Never set it below 1 full turn because the engine depends on a minimum amount of fuel for charge cooling and too lean a mixture can cause the engine to run hot. Start at 1 full turn out and accelerate the engine to high rpm. If it does not accelerate smoothly turn the screw 1/8 turn open and repeat until it accelerates smoothly from low idle to high idle.

You should not have a hard time selling the MF135 since they are a good tractor and somewhat in demand by people with small acreage.