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Magneto Shorted

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On my TD-14 the ground post on the magneto reads a short to ground with the wire from the intake manifold disconnected.  Is this normal?  I need a bit of help to see if the spark plugs are getting a spark.  The motor cranks as if there is no spark (not a pop).

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Switch in manifold grounds mag to stop it from firing.  Disconnect wire to check mag/spark plugs

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2 hours ago, Redwood said:

Switch in manifold grounds mag to stop it from firing.  Disconnect wire to check mag/spark plugs

My last post said that l did exactly what you suggest.  The question is, is the magneto post supposed to read to ground with the wire disconnected?

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No, the wire has nothing to do with whether or not the post is grounded. If there is continuity to ground with compression release out,  Check: linkage operating butterflies out of adjustment or defective, stuck butterfly shaft, broken butterfly shaft or grounding lever, or defective insulating pieces on grounding stud.

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37 minutes ago, Binderoid said:

No, the wire has nothing to do with whether or not the post is grounded. If there is continuity to ground with compression release out,  Check: linkage operating butterflies out of adjustment or defective, stuck butterfly shaft, broken butterfly shaft or grounding lever, or defective insulating pieces on grounding stud.

Forget the wire and all the stuff in the intake manifold.  I've removed the switch and the wire.  I have the stud wired through a switch on the dash to ground.  All I want to know is, what is the correct reading from the post to ground with nothing connected to it.  I am reading a dead short to ground, which would indicate that the magneto is permanently shorted out thus never allowing a spark to the plugs.

Vic

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Sorry for the confusion.  That is what I get for not reading more carefully.  You are correct the mag terminal should not be grounded with the wire disconnected.  Something is wrong with your mag internally

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9 hours ago, Redwood said:

Sorry for the confusion.  That is what I get for not reading more carefully.  You are correct the mag terminal should not be grounded with the wire disconnected.  Something is wrong with your mag internally

Thanks!  That makes total sense.  I had (slowly) decided to go my TD-14A, sitting next to it & see what it read.  Now I won't have to.  I'll have to determine whether the mag can be fixed or if I need another one.

Vic

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First off, I’m not familiar at all with magnetos... but as far as I know they have points .. 

Not just sure what you mean by a “dead short” ..  but if your magneto points are in the closed position would the mag terminal not show as being grounded out on a continuity test ? 

 

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1 hour ago, north of 60 said:

First off, I’m not familiar at all with magnetos... but as far as I know they have points .. 

Not just sure what you mean by a “dead short” ..  but if your magneto points are in the closed position would the mag terminal not show as being grounded out on a continuity test ? 

 

I don't know much about mags either, but here goes:  That terminal better not read a short to ground any time the mag is being used to fire the plugs or it would not work.  The whole purpose of the terminal is to short out the mag when in diesel mode so that the plugs are not firing. 

Vic

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3 hours ago, hector gemme said:

I have a H4 magneto counterclock wise if can help

I am interested but don't think we are supposed to deal here.  Email me at "thebunns39@gmail.com" with a price and tell me what counterclockwise means.  My mag is an H4 and is on a '42  TD-14 .

Vic

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1 hour ago, thebunns said:

I am interested but don't think we are supposed to deal here.  Email me at "thebunns39@gmail.com" with a price and tell me what counterclockwise means.  My mag is an H4 and is on a '42  TD-14 .

Vic

diesel engine have a counter clockwise rotation. also the w9 tractor gas is also. rest of gas is clockwise.  rotation is determined standing behind the engine as with any engine. same as left and right. look at you firing order and it will tell you right now. 1342 counterclockwise.

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1 hour ago, rustred said:

diesel engine have a counter clockwise rotation. also the w9 tractor gas is also. rest of gas is clockwise.  rotation is determined standing behind the engine as with any engine. same as left and right. look at you firing order and it will tell you right now. 1342 counterclockwise.

I am totally confused by your thread.  I have three diesel tractors that have clockwise rotation---viewed from the front.  I have never heard of determining the rotation of a piston engine from the rear.  If you say that diesel engines rotate counterclockwise as viewed from the rear, so do all gas engines.  Therefore as viewed from the front, diesel engines (with exceptions) and gas engines all rotate clockwise.

Vic

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totally not so and WRONG as Waylon  says,... where did you learn that rotation of an engine is viewing from the front? I would like to see that info. engine rotation is always standing behind it looking at flywheel. don't know how else to explain that. so that makes your three diesel tractors counter clock wise rotation... right? yes that's what they are. OOH and I hope we are talking distributor rotation here, as that is what you asked about and HECTOR is correct also.

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11 hours ago, rustred said:

totally not so and WRONG as Waylon  says,... where did you learn that rotation of an engine is viewing from the front? I would like to see that info. engine rotation is always standing behind it looking at flywheel. don't know how else to explain that. so that makes your three diesel tractors counter clock wise rotation... right? yes that's what they are. OOH and I hope we are talking distributor rotation here, as that is what you asked about and HECTOR is correct also.

From that logic, you are saying that gas engines rotate counterclockwise, also.  It appears that I've been wrong for a long time.  It might stem from the 1940's when my dad told me to crank our Farmall A (I still have it) clockwise.  My '39 Farmall and my crawlers all rotate the same direction, whether you stand in front of the motors or in back of them.

Vic

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yes you are cranking it clockwise standing in the front of it, BUT sit on the seat and the motor is turning counter clockwise. that is how engine rotation is determined. and yes they turn in the same direction in the front or back ,BUT from the back its called counter clockwise. anything you want to know about an engine you view from the rear of it. its a standard procedure on engines.

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not to confuse it further

 it is the mag reverse rotation( cap end/ open rotor direction)varies how it is driven from the crank gear

 KOO had a post work around for servicing mags and getting the gears going correct for current application

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52 minutes ago, rustred said:

yes you are cranking it clockwise standing in the front of it, BUT sit on the seat and the motor is turning counter clockwise. that is how engine rotation is determined. and yes they turn in the same direction in the front or back ,BUT from the back its called counter clockwise. anything you want to know about an engine you view from the rear of it. its a standard procedure on engines.

Got it!  Now, just to finish clarifying your original post you say that (as viewed from the rear) diesel engines and a W9 gas engine run counterclockwise. You then say:  "rest of gas is clockwise".  Are you saying that all other gas engines run clockwise?

Vic

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no, I was referring to Distributor Rotation. gas engines rotate clockwise on mccormicks. diesels rotate counterclockwise. only the w9 mccormick gas has a counterclockwise rotation on distributor, other gas models are clockwise. very important because you cannot get them mixed up. that is what hector was saying,... he has a counter clockwise distributor for you as this is what diesels take.

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OK!  School is out!  Thanks for the lesson.

Vic

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