Betsy's sputtering

[larryfoster]

It is a real relief.
As you can gather, I'm not very mechanically smart or talented.

My Cub is for work and I really rely on it starting now for the next month or two.

Thanks again for the gracious help

[larryfoster]

Being the eternal optimist that I am, it seems I may have spoken too soon.

Tractor ran perfectly for half hour or so and then started with the same thing again.
Heading out to check the jet and strainer and see if I can do a more detailed exam.

[Eugene]

Ignition coil. Replace.

[larryfoster]

Thanks, Eugene.

I think (but not sure) I may have replaced it before.

Is there a standard item I can get at, say, Auto Zone or do I need to get a specific one?

[staninlowerAL]

Ignition coil. Replace.

Sounds like it might be a weak coil. The type ignition system (mag or battery/distributor) that you have will determine what type coil you need. You can substitute a automotive type coil in place of the mag coil to see if it makes any difference. You need to know what type system you have, 6 or 12 volt, pos or neg ground, if external coil is the resistor internal or external. Also need to check the spark at the coil and plugs when it starts to sputter. Stan

[Eugene]

Ignition coils are available at any auto parts store. You either need a 6 volt coil if you have a 6 volt battery charging system or a 12 volt coil with internal resister for a 12 volt system.

If you have an external ballast resister, 12 volt coil without internal resister.

[larryfoster]

thank you, Stan

I don't have a magneto.
I have a generator/battery/distributor.
It is 6 volt.
I think it's called a positive ground.
My positive battery terminal is frounded to the battery box.

I think you'd call it an external coil.
Here is a pic of the old one I replaced a few years ago if this helps.

coila.jpg (21.18 KiB) Viewed 167 times

Eugene, thanks for the info

[Eugene]

Some coils have the secondary windings grounded to the coil case/mounting bracket and then to the tractor.
If the coil bracket in the photo is the current one off the tractor, polish up the inside of the bracket where the coil mounts and the side/ends where the bracket mounts to the tractor.

[staninlowerAL]

OK, your description indicates positive ground (+ battery post is grounded to the frame/battery box). You need a replacement 6v coil and as Eugene said available at any good automotive supply. When installing it, the + terminal side of the coil connects to the distributor input post/terminal. You will not need an external resister. Check the condition and gap of the points and set at .020 - .022. Sometimes the condenser will begin to break down but it can be replaced as minimal cost. Also check that the coil wire and spark plug wires are making good connections on both ends. Many believe that solid copper wires are better than carbon wires but that is probably not your immediate problem since it is running well for a short time. I just mention it in case you consider replacing the coil/plug wires. While you are into the electrical system, make sure all the connections are (shiny bright) clean and tight. The frame/sheet metal of the tractor is the ground side of the electrical circuit. That's what Eugene is referring to about cleaning/polishing the coil mounting bracket. Stan

[larryfoster]

The coil in the pic is the one I replaced.
I just posted to show what I had.
The new coil is less than 5 years old (guess)

Question on multi meter settings to check things.
I own them but am a real dunce on using them.
What should my settings be and what readings should I look for?

Do I test across the 2 posts on the coil?

The mounting bracket is probably dirty.

Thanks, again

[larryfoster]

I don't know if this is germane but...
I started the tractor a while ago and let it idle for a half hour.

It would only run on 1/2 choke.

After letting it idle, I tried to plow and sputtered after 10 minutes or so,

Another thing is I always get a lot of gas on top of the tank (not filling) when running.
There is only about 1/4 tank so it's not due to overfilling.
I sprayed a little carb cleaner into the vent hole on the cap.
Carb is always wet around the outside.
I'll be checking screws

[staninlowerAL]

I don't know if this is germane but...
I started the tractor a while ago and let it idle for a half hour.

It would only run on 1/2 choke.

After letting it idle, I tried to plow and sputtered after 10 minutes or so,

Another thing is I always get a lot of gas on top of the tank (not filling) when running.
There is only about 1/4 tank so it's not due to overfilling.
I sprayed a little carb cleaner into the vent hole on the cap.
Carb is always wet around the outside.
I'll be checking screws

I'll defer to someone else on the multimeter but if you search the topic someone has posted the expected resistance when you measure the ohms.
1. As for not running except with 1/2 choke indicates a fuel/air delivery ratio problem. From reading your description this was at idle rpm. The IH carb is a fixed jet type and the adjustment screw is for air adjustment so closing the choke reduces the air for combustion. If this air adjustment screw is set correctly, then this would mean insufficient fuel delivery to the carb.
2. Gas on top of the tank could be a bad gasket, deformed top lip where the cap attaches, excess tank pressure due to not venting or any combination of these. You should be able to blow through the small vent hole in the center of the gas cap. You can also order a free safety vented cap from the link at the top of the page.
3. Carb wet around the outside might be a bad gasket or warped carb top half from overtightening. You should not have fuel weaping down the outside.
4. I think you posted that there is a good unobstructed flow when you removed the cap/main jet but did you try a soft copper wire in the small holes in the main jet (there are several holes) then blow out with carb cleaner and air pressure?

[larryfoster]

Thanks for that detailed response.
To clarify one thing on the gas from the carb when I take the screw out.
There is an initial stream and then it's more like a dribble.
When opening the valve from the tank to the strainer, should I open it all the way or is it like some plumbing valves where one way is open and 90 degrees is closed?

I'll respond to the rest a little later.

[staninlowerAL]

Thanks for that detailed response.
To clarify one thing on the gas from the carb when I take the screw out.
There is an initial stream and then it's more like a dribble.
When opening the valve from the tank to the strainer, should I open it all the way or is it like some plumbing valves where one way is open and 90 degrees is closed?

I'll respond to the rest a little later.

When you open a drain point on the carb (either remove the drain plug on the bottom or the nut that holds the jet in place you should have a full stream without slowing until you either run out of fuel or close the valve on the tank. The initial stream at the beginning is what is in the carb bowl and empting out. The dribble that follows is not normal and is probably caused by a restriction such as the float hanging up, needle valve sticking, in-line fuel filter plug (if installed), something in the shutoff valve/filter screen/sediment bowl assy or inside the tank or a combination of several of these areas. If you have the OEM tank fuel valve, when the fuel valve is opened it should be opened as far as possible. The valve is designed to seal in the full open or full off position. You cannot run a wire/rod from the tank into the glass bowl. There is an off-set in the valve that prevents it. You might be able to blow back into the tank using the fuel line from below the tank.

[larryfoster]

Thank you Stan.
Looks like I am going to be looking for some restriction.

Where would you start?

BTW, just got back in.
Opened the vent hole on the cap, and ran the wire through the hole in the valve.

Started with no choke (probably still warm from a few hours ago), plowed the rest of my little patch (15-20 mins) perfectly.
Until the next time, I guess