Main fuel adjustment screw- Farmall 300

I am having some issues with my farmall 300. Right now I need full choke to even keep it running. I did some searches and see that I should pull the fuel bowl off and clean it out and blow out the fuel jet. Also, check for good fuel flow.

Should my sediment bowl have a screen? Mine does not. I am getting rust particles in my bowl still. Any suggestions on cleaning it out without removing the tank? I plan on doing that this winter but I need this tractor now.

Another thing, The book says to turn out main fuel adjustment screw 5 turns. I don't think my MFAS will even stay in that far out. Also it is very very loose, so loose that just in normal operation it is constantly changing adjustment. I got a new lead packing to replace any tips or pointers as far as that goes?

I posted this hear because of the high traffic volume.

Thanks in advance for any help I receive.

Ryan
 
Yes the sediment bowl should have a screen in it. Also your main jet should have a packing in it that will keep the needle tight so sounds like you need to put a kit in your carb
 
Yeah, that sounds like a lot of turns- most carbs are about 1 1/2 to 2 out from closed, and fine tune from there.

You might want to put a little "standpipe" in your fuel outlet from the tank (ie, the input to the sediment bulb)- drain the tank, unscrew the sediment bulb fixture, and cut a 1 inch piece of whatever size copper tubing fits into the sediment bulb fixture inlet. This will allow you to draw gas from about 1 inch above the bottom of the tank, and should help to get cleaner fuel. You still need clean and coat the tank this winter, but that should get you by for now.
 
Sounds like it may have the wrong main adjustment screw. Did it ever run right with that screw? If it did, it should be ok once you get the packing in and tight enough to hold the screw from moving. If not, most kits have the screw in them, be sure it does when you buy it.

Still be a good idea to drop the bowl and clean everything up. There may be a screen in the fitting going into the carb. If so clean it out.

There should be a screen on top of the sediment bowl, I would think. If you can't find one, go to a mower shop and get an inline screen filter. (Not a paper filter, they are too restrictive for a gravity fuel supply). That will keep the rust out of the carb until you can clean up the tank.
 
(quoted from post at 17:58:25 10/14/14) Yeah, that sounds like a lot of turns- most carbs are about 1 1/2 to 2 out from closed, and fine tune from there.

You might want to put a little "standpipe" in your fuel outlet from the tank (ie, the input to the sediment bulb)- drain the tank, unscrew the sediment bulb fixture, and cut a 1 inch piece of whatever size copper tubing fits into the sediment bulb fixture inlet. This will allow you to draw gas from about 1 inch above the bottom of the tank, and should help to get cleaner fuel. You still need clean and coat the tank this winter, but that should get you by for now.
i, Mike. He doesn't have 'most carbs', but rather a IH/Farmall 300.

Just one of my many pet peeves.........people applying their experience with their machine to every machine out there.
:cry:
 

This may seem silly to you, but any tricks to replace packing? Take out fitting and old packing then reverse? Put in new packing then fitting and the main fuel adjustment screw? Sorry for my questions.

Are screens available for the sediment bowls still? Is that what would normally catch all the rust particles?

Thanks everyone.
 
I was told close to 60 years ago to turn the adjusting screws out a couple three or so turns to start with and not to worry about the amount of turns because after the carburetors have been apart most will be different than when new but will still adjust for proper running. I was told then that when the idle is adjusted to the slow RPM's desired with the hand throttle at the lowest setting to open it up wide open to adjust the power jet. Adjust the screw until the engine will run the fastest RPM's and then turn it back in until you notice a slight slowing of the RPM's. I was told that it would be as close you could get without having the engine under load. It worked back then and has all these years. I have never had to ask how to get a tractor carburetor adjusted to run properly since. I have never hired anyone to work on any of my tractors.
 
Some years ago a friend to whom I lent my super h tuned it up and it never ran smoothly. I rebuilt the carb and found the seat had been split and would not adjust correctly. I found a replacement but it was tough to locate. Check to see if the copper seat is ok.
 
Yes the screen is available, try here: http://www.external_link.com/Sediment-Bowl-Screen-2-1-8-p/112253.htm

For the packing, just dig the old one out, put the new one in, tighten the packing nut until it snugs up on the screw.
 
On the Super H/Super M --up the main jet is NOT set like the non-super tractors. Max power is made 5 turns out, it can be turned in some if max power is not needed. As you said, I do not have problems with my 300 utility, Super M and 350, or with the H and M I sold. I go by the book and have never had trouble.
 
I use plastic tubing instead of copper- easy to find a close diameter that can be pushed into the opening.
 
Does your tractor have a Marvel carb? Does your carb have 2 fuel adjustments?

Some of the old marvel carbs, like the one on my 53 ford jubilee has 2 adjustments and a total of 3 screens. One screen is inside the tank attached to the sediment bowl. A second screen is directly above the sediment bowl. The third screen is hidden, it's on the brass elbow where the fuel line is attached to carb.

I'm not sure my 1950 framall has the third screen on carb elbow. However, the carb on farmall only has one fuel adjustment and it's acts backwards. Turn the jet all the way in for a rich fuel mix.

The larger jet on ford carb is the main jet. Turn it in and it goes lean. In summer I have to run my main jet at 2 1/2 turn out. In winter I have to run it 4 1/2 turns or it will die when governor open up. So I don't think it's very important how many turns it takes, as long as it runs as it should.

I got tired of paint flaking off inside ford tank, replaced it.

My farmall has a very clean tank. If I had a rusty tank, I would address the issue, new tank if I could get one. Or there are epoxy treatments if I couldn't buy a new tank.
 
have a 300U. The gas tank shed rust for about 5 years. I would clean the sediment bowl and every so often, take the bowl off, take the air compressor hose and blow air in the tank, and a big rust clog would come out of the tank drain hole. That tended to be the fix. I suppose the ethanol caused the rust to come out.
 

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