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Discussion Starter · #1 ·
I have this question posted in the Backyard Round Table, but haven't gotten much help yet, so I decided to post it here too.
Can someone help me?

I've been working with my Ford LGT165 for the first time in years.

This tractor has a Kohler K431AS (16hp)
Engine Spec. No.: 71187a
Engine Serial No.: 7194430

I had to clean the gas tank & carb because of the old gas. I also installed a new petcock with a screen filter in the tank & an inline filter. I checked the points & even hit them with a point file to make sure they weren't corroded. The tractor started up & ran pretty good........for a while. I was able to plow & harrow my garden, but before I finished with the disc harrow, the engine started to want to stall. I expected that the carb had probably gotten dirty again from left over crud. That isn't the case. The tank, inline filter & carb are all still looking good.
Next, I started checking out the ignition system. That's where the problem is. There is very little to no spark. I took the coil & condensor off & took them to a local small engine shop. They tested the coil & said that it was fine. When I told them that I had cleaned the points with a point file, they said that that was the problem. I'd never heard such a thing. He says that the plating on the points is too thin to even touch them with a point file any more. So, I bought a new set of points. I was going to get a new condensor too, but they had just sold their last condensor. Then, I had them test my old condensor. They said that it is good.
I came home, put the new points on & adjusted the gap to .020 in the wide open position. I even cleaned the new points with alcohol & then a clean piece of paper to make sure they were perfect.
Great.....ready to go! I hit the key & nothing.......not a single pop. The engine, of course was spinning over, but when I looked at the points opening & closing there was only sometimes the weakest little spark!
The only other thing that I can thinik of is the spark plug wire, but I would think that there would be good spark at the points even with a bad plug wire.......wouldn't there?

Unless I am wrong, it has a battery ignition system, not a magneto ignition system. It shouldn't matter about the flywheel in this case........right?

Take a look at figure 8.3 on page 73 of the Kohler K-SERIES engine service manual. I think that's the ignition system on my tractor.

What should I do next?
 

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The Magnificent
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You shouldn't see much of a spark at all at your points if the condenser is doing its job. Pretty rare, but I have seen a dead condenser. Of course, yours tested good.

The shop is right about not using a points file. That's pretty old-school. I remember telephone techs carrying a contact file in their pockets, but that was years ago.

Is 0.020" spec? Sounds a bit wide to me, but it has been centuries since I owned anything with points.

You don't mention the condition of the plugs themselves. Are they new and properly gapped? Free of crud? Are they indicating either rich or lean burn? Are they perhaps shorted.

How about those grounds? Since you believe all your ignition components to be good, how about connections? An older gentleman told me years ago, that when troubleshooting weird electrical problems, check every connection. EVERY CONNECTION. Clean all connectors, inspect every wire for crimps, cuts or shorts. Feel each wire its whole length for internal breaks.
 

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Discussion Starter · #3 ·
You shouldn't see much of a spark at all at your points if the condenser is doing its job. Pretty rare, but I have seen a dead condenser. Of course, yours tested good.
I really wonder how good his test of the condensor was. This condensor is the original one with the blue paint still on it. I think I'll buy a new one when they're in stock, just to make sure.

The shop is right about not using a points file. That's pretty old-school. I remember telephone techs carrying a contact file in their pockets, but that was years ago.
Is 0.020" spec? Sounds a bit wide to me, but it has been centuries since I owned anything with points.
0.020 is the book spec for point gap on this engine.

You don't mention the condition of the plugs themselves. Are they new and properly gapped? Free of crud? Are they indicating either rich or lean burn? Are they perhaps shorted.
I installed a new plug with the correct gap when I first got the tractor running, but I'm going to pull it & check it out again.


How about those grounds? Since you believe all your ignition components to be good, how about connections? An older gentleman told me years ago, that when troubleshooting weird electrical problems, check every connection. EVERY CONNECTION. Clean all connectors, inspect every wire for crimps, cuts or shorts. Feel each wire its whole length for internal breaks.
I've looked at the wires a little, but I'm going to start checking them all out if I can't find any other solution.
 

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First, I don't know how you can "not know" if this is a battery or mag system. If the coil has two primary terminals, one for the points/ condenser, and another running off to the key, then it's "battery"

If the coil mounts in the flywheel, it's a mag

One easy way to tell if it's a battery circuit is simply to use a test lamp or meter. On one side of the coil will be "battery" with the key on. On the other side------should be light/ no light as the points open/ close,

which brings us to....j

CHECK IT

You may have "touched" a hair of a wire or terminal, and don't actually have the points opening/ closing. Or maybe you just THINK you adjusted them, and they are never closing.

So take your test lamp/ meter and put them on the points connection. With the key on, gently turn the engine over. You should see the lamp light (points open) and go out (points closed) Much or any lamp glow with points closed shows you that there's dirt/ resistance/ maladjustment of the points.

HIGHLY suspect the condenser. There are several things than go wrong with them, all of which result in no/ poor spark. A CONDENSER DOES NOT JUST PROTECT THE POINTS. It ALSO "forms" the spark That is, lack of or a problem with a condenser will cause no/ poor spark

If you have ANY "good" condenser out of something else, you can try it for a test. It doesn't have to mount where the old one does, but it DOES have to hook electrically to the points (one side of the coil)

Last, ANY "test" of a coil or condenser should be viewed with bias, that is, any test which shows "bad" should normally be believed, but one that shows "good" should be viewed as "probably"

THE PLUG WIRE. Heck, that's EASY to eliminate--if it comes out of the coil----just pull it out, and use a clip lead from ground, and test for spark at the coil itself.

Can you post a link to your wiring diagram? My Kohler is DEFINATELY a coil/ battery ignition.
 

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Discussion Starter · #5 · (Edited)
Yea........I'm sure it is battery ignition. It has the old standard looking automotive coil with the two primary terminals & the spark plug wire out the top. I guess that I was just leaving myself open for correction, hoping that I had missed something simple. :rolleyes:

I'm really thinking that it might be the condensor, but I'll do the meter tests while I'm waiting for the dealer to get in some new condensors.

I tried to post the ignition diagrahm from the Kohler manual when I first posted this question, but wasn't able to figure out how to copy it from the PDF file to this forum. It's figure 8-3 on page 73 of the Kohler K-SERIES engine service mauual.
Here's a link to the service manual: http://www.kohlerengines.com/onlinecatalog/pdf/tp_2379.pdf
 

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my 145 sounded exactly like yours: ran for a while, then crapped out after an hour. I needed to get some stuff done and didn't want to wait for an order to come in, so I went to an auto parts place for a coil which works great. I agree it's a battery ignition: if you leave the key on, the coil will get hot and eventually burn out
 

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Make sure all connections at the key switch are good. My LGT is prone to corrosion on the terminals as they are near the battery. Do a quick test: undo the battery wire going to the coil + and use a jumper wire from the positive of the battery and connect it to the + of the coil. Now that you know you have power to the coil, check for spark. If still no spark, suspect the condensor and then the coil in that order provided the points are closing to create the ignition circuit. If you have spark, there must be a switch or harness problem. Sounds mostly like a bad condensor to me although coils do go bad too. Remember, heat and vibration are the enemies of electrical devices and components. To check for spark, you need not crank the engine to see if you have it. Simply pull the spark plug, ground it and make sure the points are closed. Now turn on the ignition or use the jumper wire to the + of the coil and using a small screwdriver, open and close the points while observing the spark plug. If the components are in good working order, you should have spark. If not, you know that you have to check the condensor and coil.:goodl:
 

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Discussion Starter · #8 ·
Well, last night after work I did some testing with my meter. The ohm meter showed that the points are making & breaking contact. I checked the voltage across the new battery's terminals & it showed 12.42 volts. Both primary terminals of the coil showed the same voltage & so didn't the hot side of the points. (with the points open)
My wife called the dealer today & they had the condensors in, so she went & got one for me. I just got done working a 20 hour day & I'm too tired to do anything with the tractor tonight. I'll put the new condensor on as soon as I have time. I really hope that will get the engine running!:praying:
 

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Discussion Starter · #9 ·
Now, I'm really embarrassed! :eek:

I installed the new condensor & the tractor still didn't start. :maddd:

I decided to pull the hood off & pull the new spark plug to check it again. I expected to find the plud soaked with gas, but it wasn't. I hooked the plug wire up & held the plug against the engine to ground it & hit the switch again. There seemed to be plenty of spark. I put the plug back in & tried to start the engine again. Still nothing. I grabbed a can of starting fluid & gave it a shot, then hit the key again. She fired up.....for a short burst, untill the shot of starter fluid was burned up. Next, I turned off the fuel petcock & pulled the float bowl off. There was another layer of fresh crud in the bottom of the bowl.:duh:

Then I pulled float off & the all needles out. I took a syringe filled with carb cleaner & injected it into the jets. After a little bit, I gently blew air throuh the jets & reassembled everything, opened the petcock & tried hitting the key again. She fired right up! :D
 
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