Will not fire and run

[Nelson 634]

I have owned this tractor for about a year. I have used it occasionally over that year. It ran 3 or 4 months ago. As I hadn't ran it for several months I took it on a little ride for about 20 min. brought it back and was trying to back up a gentle incline. Maybe 4" in 12' of rise. It stalled, restarted. Retried to back up, it stalled. I repeated this several times, exact symptoms repeated. It finally would just pop every now and then when cranking with starter motor. But would not fire and run even for short periods, just one pop every now and then. I figured low fuel away from pickup (or in this case tank drain). Put fuel in even though the front of the tank was down hill. I also drained the tank of fuel and cleaned tank and sediment bowel. Replaced the fuel with fresh fuel I just bought. I know that an engine needs three things, Air, Spark and Fuel. On mine it is sucking air into the carburetor. I put my hand over the inlet side of the carburetor. I also put pressurized air into carburetor thru air inlet side and with the carburetor off the tractor, fuel line attached. It sprayed out the intake side (the top with the flange). Pulled each plug and cleaned and re gaped plugs .023, I have a " spark plug tester" all it will tell me is that there is a spark of some kind not the quality of the spark. It still won't start and and run. Just a pop every now and then. My next move is to pull the plugs again, ground the plug and check color. I have also checked float settings, cleaned the jet as well as blow it out. Removed and cleaned the sediment bowl and fine screen. Removed and cleaned the rubber gas line. Blew it out also with air. Checked and cleaned the screen at the carburetor. I have removed the plug on the bottom of the carburetor it has fuel running out. I ran gas out for a while (soup can full). I don't know how long it took though. How fast should you fill up a soup can or "pick some other container". It has new copper wires installed by previous owner (PO). I've recharged the battery several times attempting to get it to start and run. The tractor has no problem rolling the engine over with ease even though it is a 6 Volt system.


Side note: the hydraulics do not work. Do not feel any fluid when I stick my little finger in the fill hole. Engine oil level high. Drained down to proper level. Could this in any way cause this problem. Could this get pumped to somewhere it shouldn't be.

[Glen]

Hi,
You didn't say what color the spark is when you tested it. It should make a strong blue spark that jumps about 1/4".
If the spark is weak, it might need the ignition points filed flat, or replaced.

The coil could need replacing, if the points are good, and the spark is weak.
People have said on here that Cub coils can quit after the Cub warms up, about 20 minutes of running, especially if the coil is old. Then they might work again when the engine cools off.

For the gas flow test, it should have a steady flow of gas through the carburetor drain plug hole, that doesn't stop.
When you first remove the plug, lots of gas will come out, that is gas that is in the carb, the flow through the gas line is after that.

If the Touch Control is out of fluid, you shouldn't run the engine. The pump needs fluid for lubrication.

I would either replace the pump o ring seal on the pump shaft, so it doesn't leak into the engine, or remove the pump, and put on a plate over the hole, like the Cubs without Touch Control have.

Below is a listing at TM Tractor for a pump rebuild kit.

http://www.tmtractor.com/new/hy/288fp.htm

Here is a post from the How To section about rebuilding the pump.

viewtopic.php?f=141&t=44196

Here is some info about the Touch Control pump.

To remove the pump, you have drain the system first. Remove the filler plug on the Touch Control, then the drain plug. You can run the engine briefly, like the operator's manual says, to empty the tubes.
You have to remove the tubes to remove the pump from the engine.
The tubes have 3 bolts at the upper end, and 2 bolts hold them onto the pump.

There is a gasket at the upper end of the tubes, and 2 o rings at the lower end of the tubes, the gasket and o rings come in the pump rebuild kit from TM Tractor, it showed in their info.

2 of the 4 bolts in the pump hold the pump on the engine. Looking forward from the rear, they are the upper left, and the lower right bolts. Don't remove the other 2 bolts before getting the pump to a clean work bench, it can fall apart. You can loosen them while it is on the engine.

The lock washer holding the nut on at the pump gear has to be good, to keep the nut from coming off during use. It bends over 1 flat of the nut. You have to bend the lock washer away from the nut to remove the nut. If the lock washer is still good, you can use it again.
It has to have the little tab that goes into the keyway, to prevent the nut from turning. Sometimes the tab breaks off, some people on here have said. If the tab is broken it needs a new lock washer.

Below is a new lock washer at TM Tractor, you can see what it looks like.

http://www.tmtractor.com/new/hy/562fp.htm

The pump shaft where the o ring runs has to be flat and in good condition. Sometimes the shaft wears, and there is a groove. If there is a groove, it needs repair. It may need smoothing with fine sandpaper.

Use plenty of clean Hy-Tran fluid when putting the pump together.

Below are pages from the 1955 Cub operator's manual, showing the parts of the system, and how to check or change the fluid.
On the 2nd page, be sure to do what it says in paragraph 4, to remove the air from the system. The arms should go through their full travel.

http://farmallcub.com/rudi_cub/www.clea ... age-65.jpg

http://farmallcub.com/rudi_cub/www.clea ... age-67.jpg

Below is a pic from TM Tractor of the pump gear, nut, and the lock washer.

[Nelson 634]

Glenn, I have a little in line spark plug checker (ILSPC). My plan is to pull the plugs, ground them and recheck the color of the spark, not the light in the Harbor Freight (ILSPC). It just flashes when the spark comes thru. I'm not concerned about the pump as the tractor won"t run. I'll put fluid in it if it ever starts. Thank you, Walter

[Waif]

If a magneto ignition and you have a hand crank , you could check for good magneto function of snap. And check your timing while you're at it.

Revisiting your points as mentioned for being clean,unburned and gapped properly makes sense.
Check your rotor too for a clean edge with enough meat to allow spark to jump the gap to cap towers well. And check the towers for clean surfaces for spark to travel through.
Most of your ignition wear areas will show where something it worn or burned compared to new or clean.

The occasional pop when trying to start it might or might not be spark caused. You could somehow have great compression in a cylinder and it diesels off.

Your year of Cub and ignition type and any changes from stock being known could help with other ideas.

[Nelson 634]

Waif,
1949 Serial Number 78128, Magneto Type, compression when I checked it shortly after purchase it was I think, in 90 to 110 range. If I recall correctly more toward the 90 side. Not sure I did that right, I did it one plug out at a time, turning engine over with starter.
I have noted the click sound the magneto makes when it nears the timing mark.
No changes that I would know of. I will get pictures of tractor if it ever stops raining here.
The thing that gets me is it ran fine for 20 min. just prior to trying to backup a very small incline when it stalled. Then would not fire and run other than that pop every now and then.
I feel almost comfortable that its not fuel related. I've cleaned, check and blown out every thing I can think of fuel wise.
I'll check points after I check plugs for fire across gap. I'll get back to you. Walter

[Glen]

Hi,
There is info for working on the magneto ignition points in the 1949 Cub operator's manual, on pages 30 and 31.

Below are the pages, if you don't have the manual.

http://farmallcub.com/rudi_cub/www.clea ... age-30.jpg

http://farmallcub.com/rudi_cub/www.clea ... age-31.jpg

Compression is usually checked with all the spark plugs out of the engine at the same time.
Open the throttle fully so the engine can get air for the test.

[Nelson 634]

Thanks Glenn,
I read the two pages you suggested and graciously provided. I do have a manual all though it is a reprint don't know what year it was printed. So read your suggested pages. I will reread the same pages from my reprints. To make sure I have it down. Thanks, Walter

[Nelson 634]

Glenn,

Compression is usually checked with all the spark plugs out of the engine at the same time.
Open the throttle fully so the engine can get air for the test

So I don't really know what I have for compression. I'll check that again when it quits raining.

Gets a little rough working under a tarp in the rain.

[Waif]

After you do the checks you have lined up...Your Cubs condenser might be swapped out for a known good one. A new condenser does not mean it's good. And a poor one could last as long as your ride was.

I had warning of multiple misses /sputtering of my engine before my coil failed.
If you prove spark , it could be that it is erratic due to a bad condenser. Only guessing here though.

There is a plastic or something like plastic piece the points rest on to insulate them. Be sure it's not shorting out randomly there due to a broken insulating piece. Or missing piece.
If you can check your coil wire to points for a thin spot or wear or rubbing due to missing grommet ,doing it while into the points area would be a good time to do so.

[Dale Finch]

A problem I had a while back caused alignment problems with the points, so you might check your insulator, like shown here:
http://farmallcub.com/phpBB2/viewtopic.php?f=1&t=103063&hilit=distributor+insulator
Nothing to lose checking it, and it would sure be nice if it were this simple!!

[MAGNETO]

Make sure none of your valves are sticking.

[Ruralguy57]

I want to throw in my 2 cents:

I have a 1968 IH Cub Lo-Boy. When I first got it, it did the exact same thing. I tried to drive it up an incline of about 3 feet and it stalled. It stopped and a lot of what you described. I ended up cleaning the carb which I took off and blew air in and out of it to make sure nothing was clogging the unit. I then discovered I had to change the coil. I changed the coil and traced down the cables to the distributor was backwards. The distributor has and electric unit in it and does not have points. Once I had all this traced down. On the left side there is a throttle lever that goes to unit on the right side that automatically controls the engine rpm. It is a rod and a clevice that is held on in place with 2 nuts. I had to move that ahead. I had to twist it forwards to the radiator. I tried twisting it backwards first and found it did not run well. So having adjusted that and loosened the rpm acceleration which is on the left side of the steering wheel to the right of the Touch Control if your unit has that. My rpm lever was stuck and I had to loosen it. One problem caused another problem caused another problem. I described all of this in my other link several pages back. I had to replace 2 coils on my tractor in 1 year. Just because you buy a new one it does not mean it is a good one and will last.

[Nelson 634]

Make sure none of your valves are sticking.

I have pulled the panel behind the carburetor and confirmed they are ALL moving up and down. Thanks Walter

[Nelson 634]

Waif, here are the pictures I promised.

[Nelson 634]

Every time I go near this particular cub it starts raining. The sun was shining 5 minutes before I went and got the camera.
And yes It quit 10 minutes later.

I have not been able to take a look at the points yet. Sun is suppose to shine all day tomorrow. I get photos of the points if weather permits. I also have a new condenser to replace the current condenser. Walter