Farmall Cub

After a week of no tractor then I some how had it run
drove to the tractor mechanic
he did the regulator Dist. Cap points the rotor the plugs the spark wires and the carb and he was happy with it in his shop.
Then when I went to start at the shop to leave it did not start he fussed and changed the plugs and it started .

Drove home no problems,
ran it for 2hrs today and it just went off like I hit the switch,
I did notice the new regulator he installed said 12 volt but I am sure he would have modded it to do 6 volts
as the tractor is now set up neg ground 6 volt. Could the tractor have started and ran for a while with a 12 volt regulator.

It pulls well but nothing is firing,
I tried every thing he complained about the compression but it ran for 2 hrs and died

Could it be the switch
that would be easy,

any one
Thanks
a rather frustrated
Rocket Man

Hi,

Check the battery voltage. If the generator is not charging the battery, the tractor will not run once the battery voltage runs low.

There are many possible causes but I'd start here as a quick and easy check.

Todd

Thanks the battery was reading just above six
it was really spewing oil vapor I thought it was vapor from sitting but 2 hrs of it perhaps the oil vapor messed up the points and caps etc

it was coming from the oil breather lots
but was vapor
could 2 hrs of that make it get dirty to quit

6v generator needs 6 v regulator. Were the wires switched on the coil when changed to neg. ground? May be coil problem. JMHO, put back original or go 12v one wire alternator.

i do not think the wires were switched on the coil
but would it start that well this am
and die 2 hrs later
I am a bit fresh to engines
thanks
what was all the oil vapor

Rocket Man wrote:ran it for 2hrs today and it just went off like I hit the switch.

First thoughts, ignition failure - guessing coil. Pull the distributor cap cover and check points condition. While there check for battery voltage at points with points open, ignition switch on.

Field test. Ignition points exposed and open. Ignition switch on. Coil wire close to engine block. Jump ignition points with screwdriver. Got fire from coil wire to ground. You have voltage to points. But that doesn't tell you about point condition.

Rocket Man wrote:it was really spewing oil vapor I thought it was vapor from sitting but 2 hrs of it perhaps the oil vapor messed up the points and caps etc.

No. Distributor and oil filler cap are on opposite sides of the engine.

Have you conducted compression tests?

Is this a magneto or distributor? ave you checked for fire at the coil lead or the plugs?

danovercash wrote:6v generator needs 6 v regulator. Were the wires switched on the coil when changed to neg. ground? May be coil problem. JMHO, put back original or go 12v one wire alternator.

Can point to what wire and where to change to neg ground he might have done it but your right
so can someone make a 12 v reg a 6v reg
thanks
for the help

John *.?-!.* cub owner wrote:Is this a magneto or distributor? ave you checked for fire at the coil lead or the plugs?

Distributor
They are rather black and dry is that the sign of fire..

Eugene wrote:

Rocket Man wrote:ran it for 2hrs today and it just went off like I hit the switch.

First thoughts, ignition failure - guessing coil. Pull the distributor cap cover and check points condition. While there check for battery voltage at points with points open, ignition switch on.

Field test. Ignition points exposed and open. Ignition switch on. Coil wire close to engine block. Jump ignition points with screwdriver. Got fire from coil wire to ground. You have voltage to points. But that doesn't tell you about point condition.

Rocket Man wrote:it was really spewing oil vapor I thought it was vapor from sitting but 2 hrs of it perhaps the oil vapor messed up the points and caps etc.

No. Distributor and oil filler cap are on opposite sides of the engine.

Have you conducted compression tests?

i will do the field test tomorrow,
the mechanic did complain about the compression and said it needed that done
he is away so its in the field,
it runs so well when on sound great and fires well.

The wires to the coil look original as well as others on the cub,.
the 12 volt regulator on the 6 volt system would this cause the battery not to charge and the tractor to die,
i need a better meter at the farm so I will get one tomorrow and test the battery in the field
the old analog read just over 6 but I really do not know if i read it right.
i bought what I thought would work well and be easy to fix for my market garden

when he gets back I will find out the compression numbers
Thanks

The fumes out of the oil filler tube are probably called "blow by". It is generally normal in small amounts, but could be a sign of poor compression if there is excess blow by.

The guys are trying to get a simple handle on what system is not functioning. Is it fuel? is it electrical?

For the fuel you can disconnect the fuel line into the carburetor to see if there is flow of gas that far. If so, then blow with air or use the straw in a can of carb cleaner and shoot it in the end of the main jet of the carburetor to make sure that the main jet is clean.

For the electrical you know that the battery is at about 6 volts. So, there is information above to make sure that you are getting spark.

Look for simple things first, like the battery ground wire coming loose...You can get into the more complex if necessary.

Todd

I just had it at the mechanic and he cleaned the carb there
should I clean it again.
As well he went thru the electrical
the cub is fitted with d16 plugs could that cause weak spark.
Thanks

From the description thus far, I would definitely replace the plugs, and go with D21. Between the blow-by, poor compression statement, and black plugs, I think you may have killed a set of plugs. Continue to check ignition circuit, because weak spark will contribute to the short life of the plugs.

Rocket Man, calm down. You seem to be in a mad panic, jumping from thing to thing to thing to thing and you haven't even done any diagnostics yet!

He is not much of a tractor mechanic if he put a 12V regulator on the tractor when it is clearly 6V. There is no "modding" a 12V regulator to charge a 6V system, at least not easily.

Even if the tractor was not charging, it should run off the battery for several days before needing a charge. However, we do not know the condition of the battery so it could very well be dead. Does it crank over?

First thing you should've done when the tractor died was check for spark. Pulll the center wire off the distributor cap and hold it within 1/8" of the engine block while cranking over. You should get snap-snap-snap.

Don't worry about the "oil vapor" right now. Tackle one issue at a time. The oil vapor was there when it was running. It will run with oil vapor.

The rain has got me pretty calm
I am going to head to the farm and to the field tests
He as well changed the tractor to neg ground so perhaps along the way like previous stated it might not be neg all the way,
I drove the tractor home 8 miles and ran it hard for 2 to 3 hrs before it stopped.
I am though worried about getting a zap from the coil
Thanks