[mulder75]

Craftsman 917-271131, CV16s Kohler engine. last several weeks, mower has died and needed to cool down a bit before it would re-start, then finally, no start at all. Using an ignition coil test light, I could see there was not spark. Assumed (I know, stupid) it was the ignition coil, as it looked pretty old, so I replaced it. Still no spark. Shined up the magnets on the flywheel, cleaned contacts on coil wires, still no spark. Then, with the cowl off, I was inspecting the coil wires for breaks. I hit the start key, and it started! Problem was, none of the coil wires were connected! By process of elimination, I have found that if I leave the yellow wire that comes from the Spark Advance Module off of the coil, the engine will start. Does anyone have an explanation for this?

Fox Mulder

 

[tkskagen]

Sadly by "Process of Elimination" the problem is found...

"The Truth is out There", and it's MTF!

Hope that your able to find the problem with your ignition!

Take care,
-Thomas (12)
Western Washington State

Sent from my SM-J337V using Tapatalk

 

[mulder75]

Sadly by "Process of Elimination" the problem is found...

"The Truth is out There", and it's MTF!

Hope that your able to find the problem with your ignition!

Take care,
Thomas (12)

MTF male-to-female?

 

[mowergene]

The overheating bothers me. Are all the air passages and fins clean? Getting too hot is hard on components, too.

 

[mulder75]

The overheating bothers me. Are all the air passages and fins clean? Getting too hot is hard on components, too.

What overheating problem ?

 

[38racing]

The first test to do if the coil is suspect is to try it with the kill wire detached. If you get spark then the coil is fine. Don't know anything about this advance module thing but I suggest that you follow the wire that you have disconnected when it runs and see where it goes. If it's the kill wire then it's grounded somewhere when it shouldn't be.

 

[mulder75]

The first test to do if the coil is suspect is to try it with the kill wire detached. If you get spark then the coil is fine. Don't know anything about this advance module thing but I suggest that you follow the wire that you have disconnected when it runs and see where it goes. If it's the kill wire then it's grounded somewhere when it shouldn't be.

I tried the kill wire first, no luck. The yellow wire comes out of the Advance Spark Advance Module and clips to the smaller of the two terminals on the ignition coil.

 

[tomw0]

I would bet a donut that the SAM is going toes up. They are noted for being a 'problem child' by Kohler, and Kohler has come out with a replacement that is not a SAM. The idea was that the spark timing could be controlled by the module for better starting, power at speed, and fuel economy. Apparently it was not as well tested as it should have been, so it was manufacturer discontinued.
I think you have two choices, either replace the SAM with a non-SAM magneto, or buy the replacement dohickey that Kohler recommends.
If it works with the wire disconnected, and you are happy with how it runs, go right ahead and use it that way. I don't know it it will be running with the spark at 'normal' advance(that which other models used as their fixed timing) or with the spark at a different setting. Actually, it may just have two timing settings, as there are two wires to the magneto, indicating to me two sources of signal for the magneto to fire. Or not.
I think if you fish around on the site, you'll find that they may be subject to heat failure, working fine when cold, but failing when hot.
tom

 

[mowergene]

What overheating problem ?

"last several weeks, mower has died and needed to cool down"

 

[mulder75]

"last several weeks, mower has died and needed to cool down"

Ah, I see what you saw. No, the mower is not overheating. I believe an electrical part is failing as it heats up, then works again as it cools down.

 

[rayjay]

I just converted a CV16 back to a CV15 by installing the CV15 flywheel and coil onto the CV16. While I had the flywheels side by side I compared the position of the flywheel key with the CL of the trigger magnets. The CV16 has the trigger magnets advanced quite a bit. This makes sense because the spark advance module needs some time to do it's thing with the advance curve so the trigger signal is generated early then the spark advance module triggers the spark at some later date depending on the rpm.

If you just add a non-spark advance coil to a CV16 the spark would be triggered much earlier probably resulting in poor running, hard starting, etc. I have heard of people doing it but I would not recommend it.

Having a proper centrifugal advance would be a good thing but it's difficult to do cheaply on a motor with no distributor. Having the fixed timing is why our motors have a decompressor setup so that they don't have to put a huge starter on the motor to get it past compression.

 

[mulder75]

Tom:

This is what track I an on, right now. Have seen posts on many sites regarding the defective SAMs. The 12 707 01-S Dsai Upgrade Kit runs anywhere from $130 - $180. I'm curious about you mentioning replacing the SAM with a 'non-SAM magneto'. How would I know what part to buy?

Dennis

 

[mulder75]

I would bet a donut that the SAM is going toes up. They are noted for being a 'problem child' by Kohler, and Kohler has come out with a replacement that is not a SAM. The idea was that the spark timing could be controlled by the module for better starting, power at speed, and fuel economy. Apparently it was not as well tested as it should have been, so it was manufacturer discontinued.
I think you have two choices, either replace the SAM with a non-SAM magneto, or buy the replacement dohickey that Kohler recommends.
If it works with the wire disconnected, and you are happy with how it runs, go right ahead and use it that way. I don't know it it will be running with the spark at 'normal' advance(that which other models used as their fixed timing) or with the spark at a different setting. Actually, it may just have two timing settings, as there are two wires to the magneto, indicating to me two sources of signal for the magneto to fire. Or not.
I think if you fish around on the site, you'll find that they may be subject to heat failure, working fine when cold, but failing when hot.
tom

Tom: With the yellow wire unhooked the mower runs a bit weak, but I am able to mow with it, just have to add a bit more throttle. Probably going to buy a new mower next season. Hoping to limp this one along for this season. Thanks for your excellent advice and knowledge. The conversion kit that bypasses the SAM is Kohler part 12-707-01-S. At $130 it's a little pricey for me.

 

[Cannon51]

I parted out a tractor with one of those engines a while back. https://www.mytractorforum.com/14-craftsman-sears-forum/1316935-lt1000-deciding-save-part.html
I had read that they would run on a regular coil so I put one on a tested it. It did run. The regular coil will only get to 1/8 inch from the coil, see post #3 in the linked thread. Whirly and Eric have both posted that they use these engines with a regular coil without any problem but If you can find a 15 hp flywheel (as Rayjay did) I think that would be the best solution.
Cannon

 

[38racing]

Did you try it with the yellow wire connected but the white wire disconnected from the SAM? Was that what you meant when when you said you checked kill circuit?

 

[mulder75]

Did you try it with the yellow wire connected but the white wire disconnected from the SAM? Was that what you meant when when you said you checked kill circuit?

Yes, I tried it will everything but the kill wire (white) disconnected. It would not start.

 

[mulder75]

I parted out a tractor with one of those engines a while back. https://www.mytractorforum.com/14-craftsman-sears-forum/1316935-lt1000-deciding-save-part.html
I had read that they would run on a regular coil so I put one on a tested it. It did run. The regular coil will only get to 1/8 inch from the coil, see post #3 in the linked thread. Whirly and Eric have both posted that they use these engines with a regular coil without any problem but If you can find a 15 hp flywheel (as Rayjay did) I think that would be the best solution.
Cannon

thanks for the info. Am wondering what part number a regular coil would be? I have a coil I ordered earlier this summer that was the wrong one. It has one tab for a wire. The one I see in your other post has no tab a all. I'm attaching a schematic for the CV15, is the single tab for the kill wire?

 

[Cannon51]

I have used 2 of these aftermarket coils from Amazon on different CV singles.

Ignition Coil Module For Kohler CV11 CV12.5S CV13S CV14S CV15S CV15ST Engine Mower John Deere GT225 LT133 LT155 LT160 LX173 LX255 LX266 SST15 STX30 STX38 STX46 1258404S 12-584-01S 12 584 04-S 1258401S
by Motoku $13.59

The coil I tried did have a single tab but I didn't have the kill (white) wire attached.
Cannon

 

[mulder75]

thanks for the info. Am wondering what part number a regular coil would be? I have a coil I ordered earlier this summer that was the wrong one. It has one tab for a wire. The one I see in your other post has no tab a all. I'm attaching a schematic for the CV15, is the single tab for the kill wire?

So the kill wire is left disconnected?

 

[Everlandfarm]

Tom: With the yellow wire unhooked the mower runs a bit weak, but I am able to mow with it, just have to add a bit more throttle. Probably going to buy a new mower next season. Hoping to limp this one along for this season. Thanks for your excellent advice and knowledge. The conversion kit that bypasses the SAM is Kohler part 12-707-01-S. At $130 it's a little pricey for me.

"Add a bit more throttle." ??? Mowing should always be WOT (Wide Open Throttle), remember it's an air cooled engine, mowing and trans add quite a load to the engine. Can't say that you fried this module, but after mower is engaged, WOT for cooling and the deck is happier also. JMHO.