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I have just recently acquired and older dozer. It has been sitting for roughly 5 years. My question is about the magneto, this dozer starts and warms up on gas, and then switch to diesel. I do not have any spark coming out of the magento, and I am looking for a starting point for diagnosis. Machine will run I have pull started it with my tractor and the motor sounds great! But do not want to pull start everytime. Any advice is helpful!

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Welcome aboard Matt

There is a switch that grounds the magneto when the changeover lever is in diesel ,sometimes they malfunction , Is the impulse coupling functioning on the

mag ?  The TD gas/diesel gurus will be along

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The ground out wire for the mag is not hooked up. Previous owner seemed to have unhooked it. But I can see where the wire comes from on the intake manifold. I'm not sure what you mean by the impulse coupling, I'm very new to these machines and magentos. 

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These older tractors were pretty much positive ground systems.  The impulse is a clicking sound the mag makes when turning the engine over with a crank or starter.  Points may be out of adjustment or just plain dirty.  Have you removed a plug to check for spark?  The spark plugs may be fouled or dirty and can be reset to .025 gap until you put new ones in if they look worn out.  

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1 hour ago, oldscoutdiesel said:

These older tractors were pretty much positive ground systems.  The impulse is a clicking sound the mag makes when turning the engine over with a crank or starter.  Points may be out of adjustment or just plain dirty.  Have you removed a plug to check for spark?  The spark plugs may be fouled or dirty and can be reset to .025 gap until you put new ones in if they look worn out.  

Have not removed a plug. But did remove spark wire and hold it out from the cap. And did not see spark. Going to try and check points. I am going to assume the points are under the distributor cap? 

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yep the points are indeed under the cap. the new points that are available are of a far lesser quality than those of yesteryear therefore I would suggest sanding the old ones to clean them also check the contacts on the inside of the cap for corrosion as they are brass as well as the rotor button just a few scrapes with a pocket knife or screw driver usually dose the trick and did I mention we love pictures! welcome to the forum also! there is a wealth of information here that dose not exist else where for these machines and all ya got to do is ask a question somebody will be along with an answer good luck russ 

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Maythew962110,

 Welcome Sound like your on the right track to get it starting properly for you. You have to have spark, so a tune up all the way from the mag to the plugs will not hurt. I am not a mag guy. But had similar issue with my TD6 ignition. Had to get it working good and then it started as it is suppose to.

Pictures would be great.

Regards,

 Chris

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3 hours ago, Maythew962110 said:

I'll get some pictures this afternoon, and will check the points and the impulse coupling as well. 

Thanks 

 

15 hours ago, Maythew962110 said:

Also, would anyone happen to know if it is a positive ground?

My -14A is positive ground with two six volt batteries connected in series.

Vic

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Well the impulse is working. Cleaned the points. but still no spark. I'm suspecting the condenser. I'm going to find one and replace it and see where we are. 

Also snapped a couple pictures of the ol gal 

20181010_114235.jpg

20181010_114244.jpg

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There is not any spark at the spark plug 

1 minute ago, hector gemme said:

Reinstaled the cap on and check to a cable on spark plug

 

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Looks like a old dirt pusher alright! Sounds like your gaining on it. Thanks for the pictures! Lots of good mag guys on here too. Very pretty country behind the dozer.

Regards,

 Chris

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Another different blade design I have not seen before. Did it maybe start as a loader and get converted to a dozer?

 

Trackshoes/ grousers look brand new, if the rest of undercarriage is that good your a lucky guy.

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Not sure if it may have started as a loader or not. My grandfather seemed to think it was a dozer, but the blade only moves up and down. The undercarriage is in good condition as well. Also has a spare set of tracks and cleats as well. I only had to pay 500 dollars for the machine. So I'm ecstatic everything seems to work well, no stuck steering clutches or anything. Minus the mag problem!

 

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Just saw the GM alternator. It's not original, and all alternators are negative ground. Originally there was a generator and it was negative ground.

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Inside the coil cap------there is a contact for picking the spark up and delivering to distributor cap. 

Pull the cover and polish the contact strip.

Once spark is going to distributor cap-----check distributor cap contacts (make sure all contacts are clean).

Points should be set @ .013.

I always like to pull the magneto----mount in vise and slowly turn with an air wrench.  Just so much easier to get to.

Nothing complicated---------if you are getting fire across points------you most likely just have some crud blocking your spark.  Should have a sharp blue spark when every thing is right.

Sounds like you got a bargain-----good luck.

DD

edit:   if you do pull the magneto-----take care to note the position of the rotor button so to stay in time when re-mounting the magneto.  Also note direction of rotation prior to pulling magneto--------if I am remembering correctly the mags on the TD's rotate counter clockwise (opposite direction of the gasoline engines).

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Have you looked under the seat to see which battery post is wired to ground?  Just curious!

Vic

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Like Chipman said, when I saw the alternator I am pretty sure it has been converted to negative ground.

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The TD-14A originally came with a positive ground system.  The alternator is probably a take off from a GM product and still negative ground, although you can buy conversion alternators that are wired for your positive ground system if you wanted it that way.  Nothing would be bothered by the change in polarity because the magneto needs no battery voltage to run the starting system like a distributor system would.  The lights and starter are OK with either system, but I'm not sure about a factory electric hour meter like mine has.  It might want positive ground to run.  

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1 hour ago, oldscoutdiesel said:

The TD-14A originally came with a positive ground system.  The alternator is probably a take off from a GM product and still negative ground, although you can buy conversion alternators that are wired for your positive ground system if you wanted it that way.  Nothing would be bothered by the change in polarity because the magneto needs no battery voltage to run the starting system like a distributor system would.  The lights and starter are OK with either system, but I'm not sure about a factory electric hour meter like mine has.  It might want positive ground to run.  

Are you saying that a starter will run in the same direction regardless of the way it's hooked up?

Vic

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Welcome to the forum ! 

As mentioned, there are a lot of people willing to help you out that have considerable experience with these old crawlers..

The negative vs positive ground has been covered in some detail in this forum in the past... some very good posts from Bob M and M Diesel in Feb 2009, you should be able to find them with a google search.. 

I can’t help with the magneto, I am only familiar with the distributor ignition system .. but what I can tell you is to persevere with your repair of this.. sounds like it has to be something quite minor that is preventing your spark from getting to the plugs.. and once you get it starting in gas mode,  you will be surprised at how easy it is to switch over to diesel .. so much easier than starting it in diesel mode ! 

 

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