Cub Cadet SC900 Self Propelled no start

[jb2873]

Hey everyone, I have a new to me SC900 rear wheel self propelled mower. Had been running great, only used a dozen times or so until a month ago....
Was taking a long time to get it to fire up.. over time, it went from 1 single pull, increasing over time to 6 or 7 pulls, then up to a couple dozen pulls or so to get it to cough and start.
Now it won't start at all.
What I have done:
*Pulled & inspected plug (plug looksd but is getting wet after multiple pulls ((obviously it's getting fuel)).
*Grounded out spark plug to verify spark ( no visible spark)
*Pulled fuel tank off to inspect "kill switch"
This is what has me puzzled. I have never seen a kill switch designed this way. I'm confused on how this can work if when squeezing closed the safety start lever and pull starting the mower, the metal kill tab makes contact with the metal pivoting arm....but when you let off the safety lever, that same metal grounding tab makes contact again, just on the opposite side of this same metal pivoting arm.
Can someone explain how this works and whether it should be doing this. I would think it should ground out only when releasing the safety lever.
I'm assuming my issue is either the kills switch (which may need some adjusting or a faulty coil module).
And yes, mower has fuel
Thanks

 

[ILENGINE]

The actual model and serial from the mower as well as the model information from the engine if possible.. I tried looking up the SC900 and it came back with a briggs engine, but that doesn't look like briggs

 

[jb2873]

The actual model and serial from the mower as well as the model information from the engine if possible.. I tried looking up the SC900 and it came back with a briggs engine, but that doesn't look like briggs

Hi, the model is SC900 rear wheel drive & motor ser# 5X70AU/1811131A0082 the best I can tell on the faded decal on the motor.
I'm almost certain it's a cubcadet motor and not a briggs.

 

[MowerNick]

The spot thats touching on the flywheel is the engine brake. The pad on it is not metal so it will not ground out there.

 

[Rivets]

Looks like the engine is 5C65M0 163cc Engine.

 

[Oddjob]

The fact that it got harder and harder to start and now there is no visible spark, would point in the direction of a failing coil. Sometimes it is hard to see a spark when you ground a plug. I prefer to use a spark tester. Less than $10 at Harbor Freight. It is also possible that the grounding switch got bent and it is grounding even with the safety bale pulled up. That would give you a “no spark” condition despite a good coil. If that is a possibility, I stick a piece of thin plastic, like a credit card, between the poles of the grounding switch to temporarily disable it, then test for spark.

A Cub Cadet coil will cost around $80. Amazon has a number of Chinese clones from $15-$30. I’m guessing that this is a made-in-China engine and that the made-in-China coils are what Cub Cadet in China used. So, if it were me, I’d buy the Amazon replacement rather than “OEM”.

 

[jb2873]

The spot thats touching on the flywheel is the engine brake. The pad on it is not metal so it will not ground out there.Yes, I see the brake pad that touches the "flywheel". When motor is not running, the kill switch arm touches the metal.pivot arm that this brake pad is attached to. But when the motor is running and the pad is not in contact with the flywheel, the kills switch is still contacting this same metal pivot arm that the brake is attached to, only that it's touching the opposite side of this pivot....hard to explain. I will try to take more pics for clarification.

 

[jb2873]

See pic showing with the safety lever closed ready to start vs safety lever open to stop motor.
The kill switch arm still makes contact (grounding out), whether safety lever is squeezed closed to run or released to stop motor from running. The grounding happens at two different locations on the metal pivot arm that the brake is attached to, whether its in run or kill mode.
Am I not seeing this correctly?

 

[jb2873]

My thoughts as well...my confusion is more about the kill switch operation

The fact that it got harder and harder to start and now there is no visible spark, would point in the direction of a failing coil. Sometimes it is hard to see a spark when you ground a plug. I prefer to use a spark tester. Less than $10 at Harbor Freight. It is also possible that the grounding switch got bent and it is grounding even with the safety bale pulled up. That would give you a “no spark” condition despite a good coil. If that is a possibility, I stick a piece of thin plastic, like a credit card, between the poles of the grounding switch to temporarily disable it, then test for spark.

A Cub Cadet coil will cost around $80. Amazon has a number of Chinese clones from $15-$30. I’m guessing that this is a made-in-China engine and that the made-in-China coils are what Cub Cadet in China used. So, if it were me, I’d buy the Amazon

The fact that it got harder and harder to start and now there is no visible spark, would point in the direction of a failing coil. Sometimes it is hard to see a spark when you ground a plug. I prefer to use a spark tester. Less than $10 at Harbor Freight. It is also possible that the grounding switch got bent and it is grounding even with the safety bale pulled up. That would give you a “no spark” condition despite a good coil. If that is a possibility, I stick a piece of thin plastic, like a credit card, between the poles of the grounding switch to temporarily disable it, then test for spark.

A Cub Cadet coil will cost around $80. Amazon has a number of Chinese clones from $15-$30. I’m guessing that this is a made-in-China engine and that the made-in-China coils are what Cub Cadet in China used. So, if it were me, I’d buy the Amazon replacement rather than “OEM”.

I agree....i just want to rule out the kill switch.
I'm completely confused on this kill switch design, and how this actually works based on what I'm seeing during the safety lever activated and the safety lever released (plz see my attached pics)

 

[jb2873]

Another pic showing where kill switch arm contacts metal.