super a problems

[tobacco farmer]

I am working on a super a with zenith carb. Everything electrical was replaced. the carb has been rebuilt to.
The tractor seems to run fine idleing but when you kick the belly mower in it dont seem to have the power especially when you let off the clutch. Also when you start pulling up a hill it will not run.
could it be the governer spring im clueless. Thanks in advance.

 

[banjodunn]

G'day and welcome to TBN it could be several things is the timing and point gap right, is the float level right in the carb, is the main jet right start the tractor up and give it about half throttle then open the main jet out a couple of turns (make sure you know how far you turn it so you can go back to original settings) sometimes this can dislodge any thing that may have found it's way into the jet. Did you do the carb yourself or send it out it may have just had ther needles adjusted to a base setting and still need to be tuned to your engine. Good luck and keep us informed



Jon

 

[tobacco farmer]

Well messed around with it a little more today. I put a new carb on it to see if anything changed and still the same. I took the belt off going to the mower and it will run good with it off but yet I can turn it easily by hand when its on the pulley. I took the governer housing off to and checked both springs they are good also.
PS thanks for the greeting.

 

[tobacco farmer]

well i found the problem #2 and #3 wires were switched around. Corrected them and adjusted the timing and you couldn't ask for anything better.
These little things like this drives you crazy.

 

[banjodunn]

G'day glad to hear you got it sorted, your right it's often the simple things that bring us undone hope you have hours of enjoyment



Jon

 

[BobG_in_VA]

Super A's and all of the IH offsets up thru the 140 are nigh on to bulletproof. How did the wires get crossed? Did you just buy it that way?? PS: I got a great deal on a '53 Super C because the owner had the new 6 volt battery hooked up as a negative ground....BZZZZZ. BobG in VA

 

[Soundguy]

and what problems did it have as negative ground?.. it should run fine positive or negative ground.. battery ignition or magneto. I've had my 66 cub setup as either, while doing some tests on it... just polarize the genny after the swap, before starting. ( in 66 IH went to 12v and negative ground )

soundguy

 

[BobG_in_VA]

Go ahead and hook your positive ground up as negative and see how long your 6 volt coil lasts.....have a nice day.

 

[Soundguy]

Lasts just fine. I've got -PLENTY- of antique tractors.. many converted to negative ground from positive....

You got an engineering degree? I do.

Looking at an auto xforemer. the biggest problem you can get with coil mismatched polarities is called a 'big resistance plus a little resistance' when you look at spark discharge potential on the secondary.. IE.. if your primary coil ( 1.5-3 ohms ) is inline with your secondary ( 4-8kohms ).. then you have a minute spark intensity potential drop.. very minute... 1.5 ohms plus 4k ohms anin't much difference.

Biggest difference you see with positive and negative ground differences happens at the spark plugs...

positive ground is better for long spark plug life. Lookup thermionic emmission.. or in plain terms.. 'edison effect'.

Also.. if you don't understand the concept and relationships between the parts of an ignition system, I suggest you google 'charles kettering'... might help you understand better..

soundguy

 

[BobG_in_VA]

Lasts just fine. I've got -PLENTY- of antique tractors.. many converted to negative ground from positive....

You got an engineering degree? I do.

soundguy

Gee, I knew I could count on you taking offense....Needless to say, yes there is a change in resistence, maybe you should tell the folks what a coil feels like after such a change. Does a hot potato ring a bell. Again have a nice day and please don't take offense that some folks outside of FLA can actually do some stuff without your supervision. Again, I stated that I got a great deal on a Super C because it wouldn't run worth a darn once the coil got hot....I changed the battery terminals, put in a new cheap 6volt coil, and its been running great ever since. BobG

 

[Soundguy]

I took no offense.. I just see someone spouting off bad electrical theory...

See.. you just changed your story now..

First you stated that running a coil reverse polarity ruined it.

Now you state that you bought a tractor with a coil that had been hot, and changed the coil and the problems was solved.

A hot coil is indicative of internal shorts.. usually cascade shorts which in turn cause more heat, and more shorts, and more current flow, causing more heat.. etc.

This can be caused by over -voltage.. like running 12v on a 6v coil, or it can be caused by lack of a ballast resistor on a 6v coil that needs one, less likely, it can be caused by jumping from a 12v source.. however this usually only happens on a marginl coil.. Another big reason for the cascade shorts and the hot coils are simple thermal breakdown of the insultive tar potting material... most of these coils are vintage and ar not oil filled... outright age and heat and vibration can damage the primary or secondary winding.

IMHO.. you had a coil that was thermally damaged and magically the machine ran better when you repalced the damaged coil.. that's what I see from a diagnostic engineers point of view, based on the info you have provided.

In actuality, if you want to get real technical about it.. a coil running in reverse polarity actually has more resistance inline with the secondary.. and thus, due to ohms law, there will be less circuit current ( and a voltage drop ).. so the coil should actually experience less current /heat based fatigue, thean one running correct polarity orientation that has less series resistance in the secondary.

You can use ohms law to verify this.. E=IR R=E/I. A secondary winding of 4kohms compaired to a secondary winding of 4kohms, plus 1.5 ohms. the one with the larger ohm value will technically have less series current.... as that works out.. the coil that is 'backwards' has the extra series resistance.. thus the big resistance plus the small resistance .

Bottom line.. you had a bad coil.. and it caused problems.. it wasn't a polarity problem.

Please don't -you- take offense when I call somebody out on a bit of bad electrical theory.

If you were a plumber and you heard someone giving dubious advice on plumbing.. you'd feel the same way.

soundguy

 

[BobG_in_VA]

Take a break dude....I wasn't spouting off...and I wasn't speaking to you when I reponded to the original poster that he had a very good machine... but you had to jump in. I'm betting 100 to 1 that you can't let it alone. BobG in VA out