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No spark at plug

#1

S

stonum

My riding lawn mower is an older Craftsman, model 917.271131. Motor is a Kohler model CV16S. It's always run good till recently. The starter turns the motor, but there is no spark at the plug. (I held the plug against the block and turned the starter to look for a spark). I've looked and looked for any loose electrical connections. Tried new plug and new coil with no luck. Any ideas on what to try next? Thanks


#2

ILENGINE

ILENGINE

The spec number along with the engine model number would be helpful so we can look up the correct engine. Also if this has the single wire coil unplug it and crank the engine. No spark then bad coil or plug. the reason I ask is some of the CV16 has smart spark ignition on them.


#3

StarTech

StarTech

OM says it came with spec 43527


#4

ILENGINE

ILENGINE

StarTech said:
OM says it came with spec 43527
Click to expand...
If that is the correct spec then that is a DSAM engine so may need the 12 707 01-S DSAI conversion.


#5

S

stonum

I'll look for the spec today. Does that safety kill switch under the seat ever go bad? I'm going to take a look at that safety switch today. And ILENGINE, can you tell me more about the 12 707 01-S DSAI conversion? Where is that kit available at?


#6

B

Bertrrr

Safety switches will not let your starter engage so not a safety switch issue , clean the magnets good on the flywheel and the coil where it relates to the flywheel magnets. There is a ground wire at the coil you can pull off and see if it sparks then , if it does it's not the coil


#7

StarTech

StarTech

The particular seat safety does goes bad as they run 12V through it the activate a relay which in turn disables the ignition coil circuit. So basically normal operation will require someone to be on the seat in order for the ignition coil to fire the plug.

Now with this said either seat switch or the operator present relay can be bad. To check the seat switch at home you turn the ignition switch and sit on the seat while listening for the fuel solenoid on the carburetor to click. If it clicks then the seat switch is good and probably the relay is bad. And I have seen these relay fill with so much rust that can't operate which mimic a failed seat switch. Also there a second operator present relay which normally provides engine braking via the stator upon either when operator is off the seat or you are shutting the engine by turning off the ignition switch. Also the seat switch is bypassed once the engine is running with the brake/clutch pedal up/released and the deck is engaged which creates an unsafe operating condition. A third operator present relay completes the battery charging circuit.

Your wiring schematic
1714056015877.png


#8

StarTech

StarTech

Bertrrr said:
Safety switches will not let your starter engage so not a safety switch issue , clean the magnets good on the flywheel and the coil where it relates to the flywheel magnets. There is a ground wire at the coil you can pull off and see if it sparks then , if it does it's not the coil
Click to expand...
Bert, You should look at the schematics and understand it before taking a wild guess at the system operation.

Also rust doesn't affect magnetism; though, it affects electrical conductivity and clearances.


#9

ILENGINE

ILENGINE

Bertrrr said:
Safety switches will not let your starter engage so not a safety switch issue , clean the magnets good on the flywheel and the coil where it relates to the flywheel magnets. There is a ground wire at the coil you can pull off and see if it sparks then , if it does it's not the coil
Click to expand...
Little more complicated than that. On his engine he either has the DSAM which supplies 12 volts to the coils, as well as impulse controls and has 2 terminals. The DSAI conversion also supplies 12 volts to the coils and has 3 terminals. You can't just unplug them and make it work like the single wire to ground to kill the system.


#10

ILENGINE

ILENGINE

stonum said:
I'll look for the spec today. Does that safety kill switch under the seat ever go bad? I'm going to take a look at that safety switch today. And ILENGINE, can you tell me more about the 12 707 01-S DSAI conversion? Where is that kit available at?
Click to expand...
Here is one possible place to get the DSAI system if you need that setup



#11

StarTech

StarTech

And this gives a better idea of how the DSAI coils are wired.
1714063990747.png


#12

S

stonum

To add to my fun, my alternator in my car went out this morning. So now, I'm trying to deal with 2 things at once. Plus, it's raining and cold and dark here. Anyway, here's some pics of my mower. It needs a washing, but it's just too nice a mower to give up on. I put on new belts and tires and battery, and fuel filter, ect... just 2 years ago. It's run so well up till now.aaaa.jpgbb.jpg


#13

B

Bertrrr

Good to have the schematics to reference Thanks for your input


#14

ILENGINE

ILENGINE

stonum said:
To add to my fun, my alternator in my car went out this morning. So now, I'm trying to deal with 2 things at once. Plus, it's raining and cold and dark here. Anyway, here's some pics of my mower. It needs a washing, but it's just too nice a mower to give up on. I put on new belts and tires and battery, and fuel filter, ect... just 2 years ago. It's run so well up till now.View attachment 68471View attachment 68472
Click to expand...
That is the Digital Spark Advance Module or DSAM for short. It controls spark timing and advancement. When it fails can cause a no spark issue. When doing the DSAI conversion that box can be removed and tossed in the trash because the conversion doesn't use it.


#15

S

stonum

I threw a new alternator in the car Friday, so now I can start looking closer at my mower, using the info you all have provided. Or I can go to Home Depot and buy a Murray MT 100 42 in. 13.5 HP for $1700, which isn't in my budget at all. Everything on my Craftsman works so good, I just got to get that plug sparking. Trying to cut my big lawn with my walk-behind is a major pain.

​



#16

B

billbud

stonum said:
My riding lawn mower is an older Craftsman, model 917.271131. Motor is a Kohler model CV16S. It's always run good till recently. The starter turns the motor, but there is no spark at the plug. (I held the plug against the block and turned the starter to look for a spark). I've looked and looked for any loose electrical connections. Tried new plug and new coil with no luck. Any ideas on what to try next? Thanks
Click to expand...
I would check the air gap


#17

V

VegetiveSteam

CV16 engines with no spark issues are mostly unheard of except on Craftsman mowers. On Craftsman mowers it was fairly common. The issue was normally a bad equipment relay. There are typically 3 relays somewhere under the hood. One of those has most likely failed.

I don't remember whether the relay was wired into the ignition kill circuit or if it provided power to the Spark Advance Module. If it were wired to the kill circuit, it's job would be to unground the white kill wire from the Spark Advance Module. If it's wired in the power circuit, it would provide battery voltage to the Spark Advance Module.

Simply check the red wire going to the Spark Advance Module for battery voltage with the key in the on/run position and also while cranking the engine. If you have power, disconnect the white kill wire from the Spark Advance Module and see if spark comes back.

Could it be a Spark Advance Module or ignition module issue? Sure, but the failed relay was a much more common issue. And unfortunately, you can't just move the relays from one position to another. All 3 have to be working.


#18

V

VegetiveSteam

This is from the Sear parts website. You can probably get a relay at a local parts store. Just make sure the terminals and in the same configuration and have the same numbers on each terminal.

1714235737473.png

1714235679422.png


#19

S

stonum

VegetiveSteam said:
Simply check the red wire going to the Spark Advance Module for battery voltage with the key in the on/run position and also while cranking the engine. If you have power, disconnect the white kill wire from the Spark Advance Module and see if spark comes back.
Click to expand...
I tried your suggestion. The voltage is there with ignition on and cranking. No spark at plug with white wire disconnected. I got a feeling this is going to take a while to figure out.
Also, here's those 3 relays.
voltmeter pic.jpg3 relay pic..jpg3 relay pic..jpg


#20

S

stonum

VegetiveSteam said:
This is from the Sear parts website. You can probably get a relay at a local parts store. Just make sure the terminals and in the same configuration and have the same numbers on each terminal.

View attachment 68485
Click to expand...
My next thing to try I think is to get new relays. I'm trying not to just give up on this mower, but it ran like a brand new one up till now.


#21

R

RevB

StarTech said:
Bert, You should look at the schematics and understand it before taking a wild guess at the system operation.

Also rust doesn't affect magnetism; though, it affects electrical conductivity and clearances.
Click to expand...
I have a magnetic flow sensor impeller that failed because of exfoliation of the core through rust.....so, that part about rust not affecting, depends.


#22

V

VegetiveSteam

With the results you now have, it's probably not a relay. Normally only one went bad so if you wanted to try it, you could just get one and try it in each position.

Like I mentioned, it wasn't unheard of for a Spark Advance Module or ignition module fail but it was pretty rare on a CV16. I've gotten a lot of phone calls over the years from guys who had changed the Spark Advance module and the ignition module on a Craftsman and still had no spark only to find out it was a bad relay.

If either the ignition or Spark Advance module has failed, your only option it to replace it with the 12 707 01-S kit ILENGINE mentioned.

You can try a local Kohler dealer for the part or order it online direct from Kohler. Often times the part is actually cheaper direct from Kohler.
1714246491830.png


#23

S

stonum

I may end up trying to convert to the DSAI ignition, but I'm going to look at Sears Parts and see if they still have the DSAM unit available. But I can't read one of the numbers on the old DSAM. It looks like 9921REVADSAM unit.jpgDSAM 2.jpg


#24

V

VegetiveSteam

What was the part number you used to replace the ignition module or coil?

Also, the number you would be looking for on the Spark Advance module will begin, 12 584 XX. It is NLA but you might find new old stock somewhere.

I didn't see ILENGINE's post about Amazon. That looks to be the best place to buy if you need the kit.


#25

S

stonum

VegetiveSteam said:
If either the ignition or Spark Advance module has failed, your only option it to replace it with the 12 707 01-S kit ILENGINE mentioned.
Click to expand...
Now things are getting more complicated. The mower is a 16.5 HP.... The plate on my engine says CV16S-43527. Sears Parts doesn't even acknowledge such a model. They do acknowledge CV16.5S-43527. So what do I have, a CV16S-43527 or a CV16.5S-43527? The DSAI kit is available for the CV16.5S-43527.KOHLER 16.5 emblem.jpgbb.jpg


#26

V

VegetiveSteam

You have a CV16-43527. There is no such thing as a CV16.5. That's a Craftsman marketing thing. Not a Kohler thing. If you're using Sears parts look-up, use their listing of the CV16.5 43527. It's the same thing. Sears actually got Kohler drug into a lawsuit because Sears decided to overstate the horsepower. Although on yours, they don't technically say 16.5 horsepower. It just says 16.5 OHV. They could claim that to mean anything they want it to.


#27

S

stonum

VegetiveSteam said:
You have a CV16-43527. There is no such thing as a CV16.5. That's a Craftsman marketing thing. Not a Kohler thing. If you're using Sears parts look-up, use their listing of the CV16.5 43527. It's the same thing. Sears actually got Kohler drug into a lawsuit because Sears decided to overstate the horsepower. Although on yours, they don't technically say 16.5 horsepower. It just says 16.5 OHV. They could claim that to mean anything they want it to.
Click to expand...
Interesting... appreciate that info.


#28

V

VegetiveSteam

stonum said:
Interesting... appreciate that info.
Click to expand...
This is probably more info than you care to know but, all the small engine manufacturers got involved in the horsepower lawsuit one way or another. For some it was their own doing because they misrepresented the horsepower on their engines.

Kohler pretty much told them to stick it and said feel free to check the horsepower on any of our engines. They will all come in above the horsepower they are advertised to be. We never misrepresented horsepower. Then the lawyers said, "What about Sears?" Kohler argued that was all Sears' doing and they had no part in that. The Kohler lawyers and bean counters figured out it would cost way more to fight it than to just suck it up and take the option of offering an additional year of warranty on the engines that the suit claimed to be affected.

I lived it and that extra year of warranty was a PITA to document and verify. The upside was, the extended warranty only applied to the original owner, and they had to provide a proof of purchase.


#29

S

stonum

StarTech said:
And this gives a better idea of how the DSAI coils are wired.
View attachment 68470
Click to expand...
More confusion. I look on amazon at the Stens 055-776 DSAI Kit, which it does say "Replaces OEM Numbers: Kohler: 12 707 01-S", but it shows compatibility with no mention of my CV16S-43527... It shows compatibility as this....
Compatible With/Replacement For: Kohler CH16-45509; CH16S-45509; CV16-43510, CV16-43511, CV16-43512, CV16-43513, CV16-43514, CV16-43515, CV16-43516, CV16-43517, CV16-43518, CV16-43520, CV16-43521, CV16-43522, CV16-43523, CV16-43525, CV16-43526, CV16-43528, CV16-43530, CV16-43531; CV16S-43509, CV16S-43510, CV16S-43511, CV16S-43512, CV16S-43513, CV16S-43514, CV16S-43515, CV16S-43516, CV16S-43517, CV16S-43518, CV16S-43519, CV16S-43520, CV16S-43521, CV16S-43522, CV16S-43524, CV16S-43525


#30

V

VegetiveSteam

stonum said:
More confusion. I look on amazon at the Stens 055-776 DSAI Kit, which it does say "Replaces OEM Numbers: Kohler: 12 707 01-S", but it shows compatibility with no mention of my CV16S-43527... It shows compatibility as this....
Compatible With/Replacement For: Kohler CH16-45509; CH16S-45509; CV16-43510, CV16-43511, CV16-43512, CV16-43513, CV16-43514, CV16-43515, CV16-43516, CV16-43517, CV16-43518, CV16-43520, CV16-43521, CV16-43522, CV16-43523, CV16-43525, CV16-43526, CV16-43528, CV16-43530, CV16-43531; CV16S-43509, CV16S-43510, CV16S-43511, CV16S-43512, CV16S-43513, CV16S-43514, CV16S-43515, CV16S-43516, CV16S-43517, CV16S-43518, CV16S-43519, CV16S-43520, CV16S-43521, CV16S-43522, CV16S-43524, CV16S-43525
Click to expand...
It if replaces the Kohler 12 707 01-S then it's what you need. Maybe there is more than one listing for that Stens part number but the one I found was way too expensive. The Amazon link ILENGINE provided had that actual Kohler part for $163.92. The Stens one I found was over $270.00. You can buy it right off the Kohler website for around $189.00


#31

StarTech

StarTech

From Stens Dealer website. Too bad you not Stens dealer they got a great sale price on it current as they are clearing the inventory out. Otherwise your are better buying from a Kohler dealer and not pay Stens their markup when it not on sale.

1714254779102.png


#32

S

stonum

I ordered the $163 Kohler DSAI from amazon. It's not an amazon prime product, so it may take a week to get here, but it is returnable within 30 days if it doesn't fix it. If this doesn't do it, I might give up or I guess I could search to see if the relays are still available somewhere. I know I talked about buying the Murray MT100 42 in. 13.5 HP 500cc E1350 from home depot, but I see out of 600 something customer reviews, over 100 reviews aren't good.😵‍💫


#33

Etbrown44

Etbrown44

I hope through all this you tried a new plug. Best to test around dusk so you can see it best.


#34

M

mankii

ILENGINE said:
Here is one possible place to get the DSAI system if you need that setup

Click to expand...
Searching for the Kohler part number brought this site up, but I'm suspicious of 250 in stock.
totalwireframe.com

Kohler 12-707-01-S Lawn & Garden Equipment Engine Ignition Module Genuine Original Equipment Manufacturer (OEM) Part

totalwireframe.com totalwireframe.com


#35

T

TurbineJon

stonum said:
My riding lawn mower is an older Craftsman, model 917.271131. Motor is a Kohler model CV16S. It's always run good till recently. The starter turns the motor, but there is no spark at the plug. (I held the plug against the block and turned the starter to look for a spark). I've looked and looked for any loose electrical connections. Tried new plug and new coil with no luck. Any ideas on what to try next? Thanks
Click to expand...
Test the solanoid. check there is power and feel or listed for the click


#36

S

stonum

mankii said:
Searching for the Kohler part number brought this site up, but I'm suspicious of 250 in stock.
totalwireframe.com

Kohler 12-707-01-S Lawn & Garden Equipment Engine Ignition Module Genuine Original Equipment Manufacturer (OEM) Part

totalwireframe.com totalwireframe.com
Click to expand...
That is the lowest price I've seen for sure, but I already ordered the $163 Kohler DSAI from amazon. It's taking forever to get here. Tracking says it will arrive by Monday, May 6. I'll post the result of installing the DSAI on this forum.


#37

M

mcHarley

Bertrrr said:
Safety switches will not let your starter engage so not a safety switch issue , clean the magnets good on the flywheel and the coil where it relates to the flywheel magnets. There is a ground wire at the coil you can pull off and see if it sparks then , if it does it's not the coil
Click to expand...
That is correct, but do not forget to disassemble the magnet coil and make it rust-free because rust will not give you a good grounding and result in no spark. When mounting the magnetic coil, the adjustment gap is equal to the thickness of a business card. Good luck. Harry


#38

ILENGINE

ILENGINE

mankii said:
Searching for the Kohler part number brought this site up, but I'm suspicious of 250 in stock.
totalwireframe.com

Kohler 12-707-01-S Lawn & Garden Equipment Engine Ignition Module Genuine Original Equipment Manufacturer (OEM) Part

totalwireframe.com totalwireframe.com
Click to expand...
I would be very suspicious if that is an actual OEM part are a chinese knockoff posing as an OEM part


#39

ILENGINE

ILENGINE

mcHarley said:
That is correct, but do not forget to disassemble the magnet coil and make it rust-free because rust will not give you a good grounding and result in no spark. When mounting the magnetic coil, the adjustment gap is equal to the thickness of a business card. Good luck. Harry
Click to expand...
The DSAI system is a fixed position module so no air gap to set. And the DSAM system required 12 volts at the module to operate, but can unpin the ground wire from the module and test.


#40

S

stonum

ILENGINE said:
I would be very suspicious if that is an actual OEM part are a chinese knockoff posing as an OEM part
Click to expand...
Yep, I appreciate mankii's post about the DSAI unit available at "totalwireframe.com" for a cheap $66, but something seems fishy about that website. Even mankii pointed out that "totalwireframe.com" claims to have 250 units available. It just seems kinda crazy that they would have 250 units available.


#41

V

VegetiveSteam

stonum said:
Yep, I appreciate mankii's post about the DSAI unit available at "totalwireframe.com" for a cheap $66, but something seems fishy about that website. Even mankii pointed out that "totalwireframe.com" claims to have 250 units available. It just seems kinda crazy that they would have 250 units available.
Click to expand...
It's a bogus website. About 6 months ago that same website was selling a 750ml of Blantons for $49. Yeah. Right.


#42

T

TobyU

The most surefire way to test a coil is to take the shroud off to get to it and unhook the small push on wire from it which is the kill switch.
Note that this disables always of turning off the engine so if it does start be ready with a glove or a towel to pull the coil wire off the plug to stop it.

Very rarely though, is this the case but it's always worth a shot.

I had a whole slew of these coils going bad a few years ago and it was just because they were all coming up on 20 years old and while they were good coils, they were just old.
Most would not spark at all but some would spark about every third revolution but not nearly enough to run or even try to run but occasionally give you a little pop.

I don't recommend buying the genuine Kohler coil because it's probably made in mexico, India or China anyways and even if it is made in the us, I can almost guarantee you that a new coil you buy today in a cold box will not last as long as the coil did on your mower originally.
So get the part number from the coil or from the machine and look up the proper part number and order one from eBay or Amazon from the cheapest seller you can find.
I was buying all the ones I was getting for between 32 and $36 shipped to my door.
They're still running just fine.
Of course, first check with another known good plug and preferably a used plug because it's far easier to see spark on a dirty plug and than a brand new one.


#43

T

TobyU

All this talk of safety switches and arguing back and forth..
Who cares at this point. The first thing to do is to test your coil and see if it's good or not.
I gave the method of doing that in my first post.
Also, keep the ohm meter put away because that test is worthless for a coil and it's just a very very basic one at best.
You simply can't trust a coil that owns out okay on a digital ohm meter to really work properly and real use.
You can find gross where you know for certain that coil won't work but there's too many of them that check fine but fail an actual operation so don't bother.


#44

Etbrown44

Etbrown44

I like TobyU's approach. Plus, be sure to test a new plug before you spend anything. Way too many guys have bought coils they didn't need, because often you can't see even a good spark in daylight.


#45

V

VegetiveSteam

The best way to troubleshoot anything is to make sure you understand how the system is designed to work before you start.


#46

B

bertsmobile1

Your module is gone
They are a great idea because they allow for a much better advance curve so you get better torque because when the engine sped drops, the spark retards .
However they do not last for ever because they do the advance / retard bit by tossing in some gates & resistors.
Remember electricity can not be made to travel faster, only slower.
So these bits eventually burn out.
Shame, but that is the way things go
So the conversion you have been advised to do is your only option other than replacing the engine .
Nothing you buy today will be any where near as good as the mower you currently have .


#47

C

closecut

The rust and trash in the fuel cutoff solenoid can physically jam the solenoid and prevent it from working properly.The seat switch is a common problem.Put a jumper across the wires of the switch and see if that solves the problem.If so,replace the switch for safety.
Kohler had lots of problems with the DESAI ignition,and finally abandoned it and replaced it with the old fashioned grandpa version ignition system..back to the old reliable.
All the DESAI system did was delay the firing of the plug.The initial timing was set high, and the delay was long,so timing was low at starting, to allow easy starts,and as the engine increased speed,the system decreased the time delay on the timing,thus advancing the timing.If the battery is border line,you may have trouble starting due to the high timing with the old fashioned coil.AIso, advance the coil a bit by loosening the screws,and moving it in the direction of rotation as far as possible,thus reducing timing, then resetting the gap.There is not much clearance in the coil screws,but a lttle goes a long ways on timing.
There will not be a noticeable difference in performance from my experience.


#48

C

closecut

closecut said:
The rust and trash in the fuel cutoff solenoid can physically jam the solenoid and prevent it from working properly.The seat switch is a common problem.Put a jumper across the wires of the switch and see if that solves the problem.If so,replace the switch for safety.
Kohler had lots of problems with the DESAI ignition,and finally abandoned it and replaced it with the old fashioned grandpa version ignition system..back to the old reliable.
All the DESAI system did was delay the firing of the plug.The initial timing was set high, and the delay was long,so timing was low at starting, to allow easy starts,and as the engine increased speed,the system decreased the time delay on the timing,thus advancing the timing.If the battery is border line,you may have trouble starting due to the high timing with the old fashioned coil.AIso, advance the coil a bit by loosening the screws,and moving it in the direction of rotation as far as possible,thus reducing timing, then resetting the gap.There is not much clearance in the coil screws,but a lttle goes a long ways on timing.A vaccum advance would have ebeen much better,IMHO,like in older cars.
There will not be a noticeable difference in performance from my experience.
Click to expand...


#49

T

TobyU

Etbrown44 said:
I like TobyU's approach. Plus, be sure to test a new plug before you spend anything. Way too many guys have bought coils they didn't need, because often you can't see even a good spark in daylight.
Click to expand...
This is why I also like to keep an old sooty plug around for spark testing or at least pull one out of something else that I've just watched run because it's even harder to see the spark on a brand new shiny plug.


#50

S

stonum

DSAI unit finally arrived today. Back in the saddle..... Without this LawnWorld forum, I'd be up the creek. Youtube video of my installation here...


#51

T

TobyU

It's been a while since I've looked at a cv Kohler.
I haven't seen many with the DSAM system etc.
I don't see the big deal with them it the train they even did it.
I know some kits come with flywheel so I guess some are different but why can't you use the standard coil that doesn't have or need the SAM?
Why is the conversion more complicated with 3 wires etc instead of just a coil and kill switch wire terminal on it?
The whole situation it is convoluted and stupid.
All you need is a coil and a magnet on the flywheel.
Why overcomplicate things??


#52

ILENGINE

ILENGINE

TobyU said:
It's been a while since I've looked at a cv Kohler.
I haven't seen many with the DSAM system etc.
I don't see the big deal with them it the train they even did it.
I know some kits come with flywheel so I guess some are different but why can't you use the standard coil that doesn't have or need the SAM?
Why is the conversion more complicated with 3 wires etc instead of just a coil and kill switch wire terminal on it?
The whole situation it is convoluted and stupid.
All you need is a coil and a magnet on the flywheel.
Why overcomplicate things??
Click to expand...
Good points. A lot of the issues stem from the progression of the ignition systems over the years. From the ASAM to the DSAM to the DSAI to finally MDI. The ASAM uses a different flywheel then the DSAM which is different that the fixed timing ignition. Basically they have a different key position to account for the different timing systems. I have done 1 DSAM to DSAI on a Command Twin a few years back but most of the conversions I have done have been on the Courage twin SV series from DSAM to MDI.

The entire fixed to spark advance timing comes from being able to use the same engine block and get more HP's by playing with the timing. And I am sure there other companies are using spark advance systems and not telling anybody that their engine uses spark advance. Stihl, Husqvarna, and Makita are three that come to mind off the top of my head. Briggs has gone from an induction ignition system to a capacitive discharge ignition. That is why the new ignition modules look so much different than the ones we are use to seeing. Are they spark advance, who knows.


#53

S

stonum

Now that the DSAI ignition system revived my old mower, I actually cleaned the old mower up a bit. mower 2.jpg


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