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Discussion Starter #1
Well, here's my situation. I was mowing for about 20 minutes when the engine began to stumble then died. I was not able to get it restarted for a while. I had just replaced both ignition coils a week ago and have mowed with them once and everything went great. I suspected first the fuel vent, so I cleared that. I then checked the plugs and both looked good. Finally, I decided to pull the top off the engine and decided to look things over.

One thing stuck out at me as looking strange, though I never looked at the area before to know how it was supposed to be. There's a tube coming off the carb that was hanging down and I looked at the end of it and it looks like it should be plugged onto something as the end is pretty flared out...see pic. Is this supposed to be connected somewhere?

Next, I decided to check the coils to see if maybe one of the new ones was not working right. I finally got the engine to run a bit at low-mid throttle. I pulled the plug off one and the engine quit. I restarted and pulled the other plug and the engine didn't change...so that means that coil is bad, correct?

I swapped out my old coils in its place and I got the same result with them...so either I have 3 bad coils, or something else going on with that particular side of the engine.

Long story short, I was able to pull the 325 back indoors before rain moved in off the one working cylinder. Any idea what the problem could be? Should I order yet another new coil or is there something else I'm missing...perhaps something with the tube coming off the carb?

Lastly (long post I know), the new coil that I pulled off which wasn't working had some of the fins "flared" a bit and they look like they had gotten really hot and had a rainbow color appearance.

Thanks in advance for any ideas you all might have!

2459704


2459705
 

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That tube is the float bow vent for the carb. So if the needle sticks open it won't flood the engine, it will just dump the excess fuel out the tube.

So your engine is only running on one cylinder. Test for spark on the bad cylinder. If you don't have any, test with the kill wire not on the coil. Idk, maybe there's a spark module and won't spark with the wire off. But, could be a valve issue so next is a compression test and if that fails, a leak down test.


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Discussion Starter #3
So your engine is only running on one cylinder. Test for spark on the bad cylinder. If you don't have any, test with the kill wire not on the coil. Idk, maybe there's a spark module and won't spark with the wire off. But, could be a valve issue so next is a compression test and if that fails, a leak down test.


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I'm a bit lost on this part...test with the kill wire? I'm not really sure what you mean with that.
 

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I'm a bit lost on this part...test with the kill wire? I'm not really sure what you mean with that.
Well, you already have a coil on the bad cylinder, so test for spark. If there is none, remove the wire(s) from the coil and test for spark again.


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Discussion Starter #8
Unfortuantely, if my 325 has a time delay module, I cannot seem to find it. I looked around this morning and I do not see anything that closely resembles one at all. Would the part look different than I'm expecting on this particular model?

As for swapping coils side to side, I'll have to try that out in a little while to see if that changes anything at all...thanks for the tip!
 

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Unfortuantely, if my 325 has a time delay module, I cannot seem to find it. I looked around this morning and I do not see anything that closely resembles one at all. Would the part look different than I'm expecting on this particular model?

As for swapping coils side to side, I'll have to try that out in a little while to see if that changes anything at all...thanks for the tip!
The time delay module will be zip tied along the engine harness somewhere I think. Maybe you don't have one. I think they normally kill spark to both when they fail.


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Discussion Starter #10
The time delay module will be zip tied along the engine harness somewhere I think. Maybe you don't have one. I think they normally kill spark to both when they fail.


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Yep, nothing like that to be seen. About the closest thing I can find where a few wires hook up is a small circuit board on the engine near the starter...but from what I can tell that's a whole different part than the time delay module.

Hopefully swapping the good/bad coils locations will give me some insights when I can try that out in a bit.
 

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Just to eliminate this suspect, do you have the correct gab between the flywheel magnets and the coils? Roughly speaking a business card can be used to set that gap. Insert the card between the flywheel magnet and the loosely mounted coil. The magnet will pull the coil up to the card surface. If not, push it so it sandwiches the card between the flywheel magnet and the coil. Tighten the coil bolts and remove the card. Do the same for both.

Not sure what you meant by the "fins are flared" on the new coil that quit. If they were set with too little, or no gap, they may have been rubbing on the flywheel, and maybe heating it to produce the damage that you saw. Maybe a pic can help someone provide a suggestion on that.

Let us know what you can find out.
 

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Discussion Starter #12
I will have to check that gap too...I hadn't even realized there was a specific gap that I needed there. That very well could be the problem with the one coil. Are these kind of like plugs where a specific gap is needed then? Still learning quite a bit of this stuff!
 

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I will have to check that gap too...I hadn't even realized there was a specific gap that I needed there. That very well could be the problem with the one coil. Are these kind of like plugs where a specific gap is needed then? Still learning quite a bit of this stuff!
Yes, .010-.012" is common, about the thickness of a greeting card or business card.


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Do you know what year your 325 is?
 

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Discussion Starter #15
It's a 1999 325. I haven't had a chance to do anything with it yet today (sprinkler line repair problems instead!), but I'll check that gap first chance I get later today.
 

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Discussion Starter #16
I finally got a chance to play around with it and here's what I've discovered. I did use a business card to set the coil gaps this time around. The right side (from seat) coil seems to be fine. After starting I pull that plug wire and it dies. The left hand coil I pull the plug and nothing changes.

Now, if have the mower running like this, on one cylinder I assume, it will run for about two minutes before it starts sputtering. If I play with the throttle I can keep it going for maybe another 30 seconds before it dies.

I tried the other old coil I pulled out originally and it did the same as the left side one described above. The other replacement coil that I used for about a week was the same story...no change with either when I pull that plug wire.

I dropped in some new (and gapped) spark plugs and gave that a try...no change from above.

Lastly, I swapped the good right side coil and the left side coil to make sure that was what was going on. With the good coil on the left and suspected bad one on the right, I was able to start it up and it ran a little better than before. If I pull the left side coil plug (the good one), it dies. If I pull the right side, no change.

I assume this means that the one coil is for sure bad and that's my issue? Also, after swapping the coil to the other side, I mentioned it ran a bit better and it would run without dying at all this way. For grins, I tried starting up the mower deck and it bogs down heavily, but does not die. I can tell the blades aren't at full speed though either. After turning off the mower deck, the engine speeds back up like it should.

Have I missed anything with this round of troubleshooting, or is it just another coil I need to order and wait for!
 

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How old is the battery, bad battery can cause issues with engaging the pto(blades) Take battery to auto store and have it checked. Bad ground dirty cables same issue with it bogging down.

Voltage regulator?
 

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Discussion Starter #18
The battery is brand new. The dealer threw in a new battery a few weeks ago when I bought the 325. All the connections look clean/good.
 

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Did you run the engine with both kill wires disconnected from the coils? Outside of the plug wire, unless I'm mistaken, there is only one wire on each coil, I'd try disconnecting it try running engine.

Also, not sure if it's possible to flip the coils but any chance the one that doesn't work is upside down?
 

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Discussion Starter #20
I didn’t try removing the wires on top of the coils. I can give that a shot. I don’t think they can be flipped but I’ll look next time I pop one off.
 
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