137 replies to this topic

[dodge trucker]

5 volts at the spark plug... huh?

[accidentalchild]

The starter generator I bought new and was tested last summer when I put it in.

[accidentalchild]

5 volts at the spark plug... huh?

I just hooked up my voltmeter directly to the spark plug wire after disconnecting it from the spark plug. I used an alligator clip to attach it. I would then turn the key as if to start it and see how many volts there were. Since I have a good running s14d I tried the same test with it. The 1250 was getting 5 volts and less and the 1476 was getting consistently just under 12v.

[accidentalchild]

The ignition coil is only getting about five volts. I will pick up a spark tester and check that out.

[grattone]

Disconnect the wire/s going to the points from the coil negative side--- then use the meter and measure from the + wire on the coil (still connected) RED lead on meter to +   black lead to ground  Should read 12 v approx. with switch on....if it does  Good  Next step remove plug and make sure it is grounded to the head away from the spark plug hole and it is still connected to the coil---- take a jumper wire and short the Negative side of the coil to the head (Tap it to ground with switch on) every time it makes and breaks connection you should see the plug spark  if it does Good. Now you will  need to check the points.

[1967bolens collector]

If the spark isn't a nice blue color then u have a problem

[accidentalchild]

Disconnect the wire/s going to the points from the coil negative side--- then use the meter and measure from the + wire on the coil (still connected) RED lead on meter to +   black lead to ground  Should read 12 v approx. with switch on....if it does  Good  Next step remove plug and make sure it is grounded to the head away from the spark plug hole and it is still connected to the coil---- take a jumper wire and short the Negative side of the coil to the head (Tap it to ground with switch on) every time it makes and breaks connection you should see the plug spark  if it does Good. Now you will  need to check the points.

thanks , will check that out.

[EricFromPa]

maybe that Ballast resistor is no good or the Coil has an Internal resistor? If the coil has an internal resistor you don't need the Ballast resistor.It will not spark with Both.It should say on the side of the coil if it has an internal resistor.

 

Check and see if there is 12v going into the Ballast resistor.You might be OK up to that point.That will eliminate most of the wiring as the problem if it does.

Edited by EricFromPa, March 03, 2016 - 09:52 PM.

[LPBolens]

The Wisconsin singles are notorious for cranking over slowly. When I first got one, I thought it could never start cranking that slowly. But it did, and does.

 

This may not work for you, but when I had a weak, intermittent spark on a 1250 that had been sitting for a long time, and the tractor would not start, it turned out to be oil varnish built up under the points so they could not ground properly. Once I cleaned up the points box, and re-installed the points, the tractor fired up and ran fine.

[accidentalchild]

I picked up a couple of these inline bulb type spark testers as they were the only ones I could find locally . The bulb sure does nothing when I crank it over.

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[accidentalchild]

Here is some pictures of how this is wired.

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[accidentalchild]

When I turn the engine over by hand by grabbing the pulley and turning it I can feel the pressure in the engine increasing until it gets hard to move and then after the pressure is built up I hear the air hissing out of the leak around the spark plug.

[Bruce Dorsi]

It appears you have two red wires attached to the + side of the coil.   .....One comes from the ballast resistor. .....Where does the other red wire go? 

 

The blue or black wire attached to the neg  (-) side of the coil is attached where? ....It should be attached to the external stud at the breaker box.

[accidentalchild]

It appears you have two red wires attached to the + side of the coil.   .....One comes from the ballast resistor. .....Where does the other red wire go? 
 
The blue or black wire attached to the neg  (-) side of the coil is attached where? ....It should be attached to the external stud at the breaker box.

the blue wire is attached to the stud on the breaker box the second red wire goes to the fuel pump.

[accidentalchild]

Well it moved! As I was pulling it with the 4x4 mower.

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