H Starting Problem

I have finally reached the stage of trying to get my recently purchased 1951 H started. I have started it on ether, and have run a full can of brake cleaner through it and it ran beautifully. However, it will not run on gas. Here is what I have done to date to try and resolve this problem.

1. Disassembled and cleaned the entire carb, including all jets. All ports have been blown with air at 90psi and are clear.

2. Removed the varnish on the float valve plunger so it falls freely when the float is in the down position so gas can enter the carb.

3. Verified that the carb is getting gas by opening the drain plug on the carb body and letting the gas run out.

4. Verified that the fuel line is clean and running a steady stream.

5. Checked the carb suction with the air cleaner pipe off by covering it with my hand. It has a very strong suction, which tells me the engine is pulling the air through as it should.

6. Checked the inlet manifold gasket for leaks. None that I can find.

7. Hired the local "...best carb guy in the region..." to see if he could figure out what is wrong. He went through all the above steps again, put it back together, and tried to start it. Fired right off on ether, but will not start on gas.

I have been trying to solve this problem for the past week. Am very frustrated. What might I be missing? If it won't start standing still, will pull starting it make any difference? Don't see why it would, but am out of ideas.

Need help badly. This thing is driving me crazy.

have you by chance drained all the old gas out and put in fresh may have water or something in it

Check all intake gaskets for leakage. We were just done this road and the problem was a bad gasket. Could try spraying WD40 or some thing simular around all gaskets and if it pops you found the problem.

Iḿ not shure if it is relevant but Is the governor working properly? throttle correct set?

are the float giving the right level? attach a hose on drain and check against mark on body.

If you get it runing on gas you can check for leaks by spraying ether around gaskets etc.
and ofcoures are mainjet giving proper amount of gas?

Go over to Page 4 on this forum and read what Dan G found wrong with his Farmall H not starting. Make sure you open the main jet adjusting screw. With your hand covering the throat of the carburetor your engine should start. Either the intake manifold is leaking or the problem is in the carburetor. Hal
PS: You need good intake manifold vacuum to pull that fuel into the engine.

I've just done this...


See here:

http://ytforums.ytmag.com/viewtopic.php?t=620080

I went thru everything but rotating the distrib, cuz I never moved it... perhaps there's something here....Mine was a bad intake gasket, sucked air thru manifold instead of thru carb. My carb thoat had intake, but I didn't realized how weak it was until I replaced the intake/exhaust manifold gasket. Yours may be different, but you may find something in this thread to help.

Good luck!

If there is fuel to the carb inlet port (fuel runs out like a small soda straw) (there is a screen at that fitting!)
If you have the Idle ports and main jet clean (it is not the load screw on the front bottom, that adjusts the total main fuel within a range of richness, the main jet is inside)
If you have the choke plate working.
If you have fuel in the float bowl.
If it runs on supplemental fuel.
If the carb gasket at the manifold is good.
If when you hold your hand over the inlet and crank, it floods gasoline back out the inlet (it should) If none it is not getting fuel from the carb.
It will start and run! Jim

Jim,

On your list of "ifs", the only item that I don't have is fuel running out of the inlet when my hand is held over it. The carb mechanic that worked with me also said the same thing should happen but he was unable to figure out why it didn't do that. He also said that the suction on his hand was very strong so he felt it should be more than adequate to pull the fuel into the engine.

A friend suggested that if it is running on supplemental fuel (ether or brake cleaner) that perhaps the problem is that it needs a higher octane fuel. I am using fresh fuel, 87 octane, and it might have some ethanol in it, as most fuels do these days. Do you think this could be the problem? All my other engines run OK on this fuel, so I tend to discount this thought, but as you can tell, I am desperatly searching for an answer and am willing to try most anything.

Spray some of that brake cleaner over the area where your intake manifold is bolted to the engine block while someone makes an attempt to start the engine. If the engine fires you have a manifold leak. Hal

I firmly believe the issue is in the carb. There should be fuel to the intake if there is vacuum on the inlet when cranking. There are several items in the mix.
The fuel strainer at the carb inlet.
The seat of the needle and seat (float control valve) can be plugged (above needle)
The float can be touching the side of the carb lower housing and binding in the shut position
The Needle can be stuck in the seat.
The float could be adjusted so low that the needle cannot open.
The main jet could be plugged (or its passages) to the venturi
The venturi could be in wrong, or missing! They hare fragile old pot metal and often decay/oxidize.
These issues can and have caused no fuel at the combustion chamber. Jim

It sounds like you are getting fuel to the float bowl.

I don't have a manual that shows the carb on a Super H, but if you close the choke and crank the engine half a dozen turns or so, will fuel drip out of the weep hole in the bottom of the carb inlet ? Or if you put you hand over the inlet and crank the motor, Do you get fuel on pooling in the bottom of the carb inlet ?

If not, look for a blockage between the bowl and the emusion tube well. Can you blow air backwards through the main jet ?


Greg