Ignition, no spark problem help!

original possum · Post by **original possum** » Mon Dec 14, 2015 8:02 pm

Years ago I found that the best way to test a condenser was to remove it, charge it on the external post of the distributor using the screwdriver trick while grounding the base, and throw it to someone while it was charged. If he cussed a lot then the condenser was good, at least until he dropped it or threw it at you.

jtrichard · Post by **jtrichard** » Mon Dec 14, 2015 9:13 pm

PatPax wrote:Will someone please explain in simple terms what is a "positive ground"

And how to properly hook up the coil, as I think the previous owner had it wired opposite as shown in the manual. It ran that way for the 8 months I have owned it. BUT now no spark.

WHEN the battery POS./+ is hooked to the frame it is a positive system

"""

As already stated, you hook the positive side of the battery to your frame, and the negative side to your starter. The current goes through its usual circle opposite that of a negative ground. For me sometimes it's annoying to figure out how to hook up a voltmeter.""""......

YOU need to see how yours is hooked-up you can NOT just change it back and forth ....FIRST do you still have a generator? or has it been upgraded to an alternator? IF you have an alternator you will have (ALMOST GUARANTEED) a negative system ........ IF you have NEG. ground then you hook power to the + side of the coil IF POS. ground then you hook power to the = side of the coil

Stan Disbrow · Post by **Stan Disbrow** » Tue Dec 15, 2015 5:56 am

Hi,

Voltmeter easy. The red lead is positive, the black negative.

On the old mechanical pointer meters, this was more important because if you got it wrong, the needle whacked the stop pretty hard and might be damaged.

On the modern digital meters, the LCD display will show the correct voltage no matter what. If the leads are swapped, you will see a negative sign.

For our usual purposes, just ignore that sign.

Stan

Stan Disbrow · Post by **Stan Disbrow** » Tue Dec 15, 2015 5:59 am

original possum wrote:Years ago I found that the best way to test a condenser was to remove it, charge it on the external post of the distributor using the screwdriver trick while grounding the base, and throw it to someone while it was charged. If he cussed a lot then the condenser was good, at least until he dropped it or threw it at you.

Hi,

On 12 volts? I wouldn't even notice. Now, let me toss you one from a kilowatt radio transmitter amplifier. 3000 volts.

I know you'll get a charge out of that!

Stan

sl1250c · Post by **sl1250c** » Tue Dec 15, 2015 6:20 am

Is there a resistor in line with the coil check for bad connection as when load of the spark the voltage drops out.

PatPax · Post by **PatPax** » Tue Dec 15, 2015 8:53 am

YOU need to see how yours is hooked-up you can NOT just change it back and forth ....FIRST do you still have a generator? or has it been upgraded to an alternator? IF you have an alternator you will have (ALMOST GUARANTEED) a negative system ........ IF you have NEG. ground then you hook power to the + side of the coil IF POS. ground then you hook power to the = side of the coil

THANK YOU jrichard! At some point in its 54 yr life someone DID change it to an alternator. I would not of known to check that if you had not brought it to my attention.

I just can't seem to figure out this "no spark" problem & truly need this machine back running to push snow. My brain is starting to have a "no spark" problem

Stan Disbrow · Post by **Stan Disbrow** » Tue Dec 15, 2015 9:22 am

Hi,

Well, alternators are negative ground. The battery had to be connected that way at that point or it would discharge rather than charge. So, that settles that.

Have you hooked a test spark plug to the coil directly and manually operated the points yet? You need to know if your issue is no high voltage generation or a fault with the cap/rotor/timing.

Stan

PatPax · Post by **PatPax** » Tue Dec 15, 2015 4:03 pm

I live "out" so a 2 hour round trip to NAPA... they tested the coil @ 10 volts, I got same with volt meter. They said it "should" still start BUT I bought a new one anyway and a timing light!. The coil says on it "external resistor needed". I can not find a resistor on the crawler????

Stan,

]Next step is to hook a spark plug onto the coil lead. I usually stick a spare plug wire into the coil and lay the test plug anywhere handy on the engine with the gap such I can see a spark.

Then, with the cap off and the points open, I switch on the ignition and use a screwdriver tip to jump across the points. That makes a magnetic field inside the coil. Then, I pull the screwdriver off and there should be a spark at the test plug.

Still no spark while doing the above

gregjo1948 · Post by **gregjo1948** » Wed Dec 16, 2015 5:29 am

When doing the test, did you have power to the points? gregjo1948

Stan Disbrow · Post by **Stan Disbrow** » Wed Dec 16, 2015 5:33 am

Hi,

With it in the same state, power on and points open, check the voltage with a meter on the live side of the point unit itself. I suspect you have lost the connection between the points and the coil.

Stan

PatPax · Post by **PatPax** » Wed Dec 16, 2015 7:56 am

When I turn switch on I have power to positive side of coil & none to negative side with points open or closed same result.

Stan Disbrow · Post by **Stan Disbrow** » Wed Dec 16, 2015 8:36 am

Hi,

If the power is there at the dist side of the coil, then there is a fault in the connecting wire between the two.

Always suspect the crimped on connectors on wires. They like to go bad.

If no power on the terminal of the coil where the wire connects from the distributor, then the coil primary winding is bad.

Stan

PatPax · Post by **PatPax** » Wed Dec 16, 2015 10:48 am

How much wobble is a distributor allowed to have? I have a slight wobble aprox. .030-.050

jtrichard · Post by **jtrichard** » Wed Dec 16, 2015 12:10 pm

you need to get the dizzy re-bushed/rebuilt should have almost NO side play....030/.050 is NOT slight

PatPax · Post by **PatPax** » Wed Dec 16, 2015 12:31 pm

OOPS .003-.005 my typo. Is that too much?

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Ignition, no spark problem help!

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