Need help: MF35 sputters and stalls

[fishguts]

I've got an old MF 35 that usually runs well enough, but recently it sputters very badly as soon as I start it. It will stay running if I work the choke in and out, but if I let the choke back in, it will sputter some more and then stall.
Any thoughts?

 

[mlauk]

Sound like it's not getting enough gas. I would clean your sediment bowl and check the flow of gas to the carburetor.

 

[Soundguy]

'Needs choke to run'

the classic reasons for this are:

1, weak spark. ( choke enriches the mix... rich mixes fire on weak sparks )

2, vacume leak. ( choke adds manifold vacume to make up for the vacume leak.. vacume leak leans the mix.. choke enriches the mix ).. leak could be a cracked manifold or bad gasket at the manifold or carb to manifold.. or carb halves gasket, where present.. etc.

3, fuel obstruction. ( choke adds manifold vacume.. this helps pull fuel past clogs and dirty needles.. etc. Screw the main needle in ( if it has adjustable main ), count turns.. open needle back out that many.. try it.. or thread in, count turns. then pull needle, then give a shot of cleaner down the hole with a straw.. etc. then repalce needle..

soundguy

 

[gemini5362]

I've got an old MF 35 that usually runs well enough, but recently it sputters very badly as soon as I start it. It will stay running if I work the choke in and out, but if I let the choke back in, it will sputter some more and then stall.
Any thoughts?

let me give you one more piece of advice every body else already took the good stuff so I guess I can throw in the off the wall. Take the breather off and try starting it with it off and see if that makes a difference, Take the distributor cap off and spray everything with wd 40, then put cap back on and try to start it. How old are the spark plug wires, and last but not least has the gas gotten any water in it. If it does not look fresh drain the gas and try fresh gas.

 

[fishguts]

Just got back from messin' with the tractor. I unhooked the fuel line at the carb--plenty of flow. I took the carb off and took it apart. I have no idea what i was looking at or for, but everything looked fine. I put it back on, hooked up the gas and fired it up. It still sputtered and stalled. For some reason, I tried turning the big brass screw on top and in front of the carb--just a half-turn counterclockwise. Bingo. It perked right up and ran smooth. Simple fix.
I assume that screw restricts gas flow? Whatever it is, it seemed to be the problem.
Thanks for the suggestions.

 

[Soundguy]

I don't know what model carb you had.. but that was very likely the main needle... it can get dirt under it.. or it may have just been adjusted too lean to begin with.

soundguy