2017 Cub Cadet Challenger 750 EPS won't start

[PierceIt]

Hi everyone - I was driving my 2017 Cub Cadet Challenger 750 EPS today on the ranch when it dies on me. It started right up - and then as i was driving after about 50 feet the engine just turned off. It was running perfect before it cut out on me. No alarms, no weird sounds or smells. It just turned off. 

When I turn the ignition key, the starter cranks away and the battery and starter turns fast and strong - but the engine doesn't start.

I've confirmed gas flow to the carb - that the fuel filters are clean and clear. I've replaced the spark plug with a brand new one. I checked every fuse with a meter. I have confirmed air filters and airflow are good. 

But the darn thing cranks away without the engine even making a sputter or even attempting to fire.

Is there a kill switch somewhere that could have been tripped? I checked the seatbelt sensor, the brake sensor, and parking gear sensor - all are working and i'm in Park, pressing down on the brake, and have the seatbelt latched when i try to start. but - nada!

It acts like it isn't getting a spark. but like i said i put in a new spark plug. I have a feeling there is a sensor or an electrical kill switch somewhere that tripped. 

open to any ideas.

thanks all

Pierce

[Travis]

Pull the spark plug out , and put the wire back on it, ground the plug to something metal, engine head, whatever, and crank it over, look for a spark at the electrode. Another way to check for spark is to take the plug out, put a small amount of gasoline down the plug hole, reinstall the plug and wire. Turn it over. If it cranks then dies. Fuel problem.

If nothing, no spark

[PierceIt]

Thanks Travis. I should have added that have done what you suggested too - I pulled the plug out, connected it to the spark plug wire and while holding it near the engine head turned the key in the ignition.  There was a strong blue spark and gas/vapor sprayed out of the engine head through the spark plug hole as the piston moved while the engine cranked. I then put a little oil and gas down the spark plug hole, re-inserted the spark plug and tried to start again. It seemed to have more compression this time and the starter cranked a bit slower for a few seconds but still the engine didn’t so much as sputter one bit or try to start. 

I’m at a loss for what to explore next. I’ve got gas, air, and spark. But the engine doesn’t even try to sputter or ignite. Compression might be a hair low because the starter does seem to be turning just a hair faster than usual. 

I had also swapped the gas out for new gas.  Didn’t make a difference either.

 

 

[Travis]

If you have Fuel, Spark and Compression, the next thing you need is the Correct timing for the plug to fire the spark.

I'm not sure how invasive it is to check timing on this machine, so I would look at timing as a last resort. Unless you know more.

[John Taylor]

Valve adjustment! Or timing

[PierceIt]

I've done a dry and wet compression test and based on the results I am now leaning towards this being either piston rings or timing chain or  timing woodruff key 

stay tuned

[PierceIt]

Turns out the timing chain came off due to worn camshaft and sprockets. Need to replace $700 in parts.

Never missed an oil change and always used good synthetic oil. The metal inside these engines seems to be very cheap metal. 

Pretty disappointing since it only has 180 hours on it and less than 500 miles. 

[Thomas osterhout]

Same here 1500 mileslots of problems with mine burns oil now too junk

[PierceIt]

Well after spending $2k to rebuild the engine (valves, piston, rings, timing chain, camshaft and sprockets) it was running as good as new again.... but only for a total of 6 hours when out of no where with no signs of issues or warning whatsoever while driving at a slow speed a loud  "clunk!" noise came from the engine and the engine is totally f*cked again, dumped it's oil out everywhere and is seized up. unbelievable! Something is fundamentally wrong with this engine. Me and the mechanics are completely baffled at what a total POS this thing is. I have a giant piece of trash sitting in my shop right now that i've spent way too much money on. It's not even 3 years old yet. super frustrated. No warranty, no help from cub cadet, and the dealer where i purchased it no longer sells them any more because of all the issues they've have come back on these. This is the worst purchase i have ever made

[Thomas osterhout]

I hear you I've got an 18 its motor is junk I've heard that some other brand motors may fit with a little work mine burns oil with 1500 miles had same prob with timing chain valves

[PierceIt]

According to the Better Business Bureau there's a lot of people waging completes about this same motor: https://www.bbb.org/us/tx/mckinney/profile/atv/hisun-motors-corp-usa-0875-90395182/complaints

 

[Terry Hering]

On 3/21/2020 at 8:56 PM, PierceIt said:

Hi everyone - I was driving my 2017 Cub Cadet Challenger 750 EPS today on the ranch when it dies on me. It started right up - and then as i was driving after about 50 feet the engine just turned off. It was running perfect before it cut out on me. No alarms, no weird sounds or smells. It just turned off. 

When I turn the ignition key, the starter cranks away and the battery and starter turns fast and strong - but the engine doesn't start.

I've confirmed gas flow to the carb - that the fuel filters are clean and clear. I've replaced the spark plug with a brand new one. I checked every fuse with a meter. I have confirmed air filters and airflow are good. 

But the darn thing cranks away without the engine even making a sputter or even attempting to fire.

Is there a kill switch somewhere that could have been tripped? I checked the seatbelt sensor, the brake sensor, and parking gear sensor - all are working and i'm in Park, pressing down on the brake, and have the seatbelt latched when i try to start. but - nada!

It acts like it isn't getting a spark. but like i said i put in a new spark plug. I have a feeling there is a sensor or an electrical kill switch somewhere that tripped. 

open to any ideas.

thanks all

Pierce

 replace the spark plug wire. I had the same thing happen to me and there's carbon film elements that are in that wire and they just fall apart so I replaced it with a real spark plug wire with wire in it

 I'm hoping that would solve your problem. I put a real spark plug wire in and made it myself.

[Terry Hering]

 I hope that solves your problem? Mine was brand new when it happened to me. and it is really easy to make a new one, cuz if you order one for like $50. I'm learning a lot since I bought mine brand new. because dealers don't tell a whole lot when you ask him questions.

[Courtney Combs]

How do you time s 750

[TheFix]

I am working on a 2017 Cub Cadet Challenger 750. I picked this unit up from the customer because it was running badly.  When I got it to my shop it would not run at all.  It did not have spark and the fuel pump was not priming, meaning that when I turn the ignition to on position, you could not hear the fuel pump running to prime the fuel system.  I replaced the fuel pump and the fuse box containing the fuel pump relay, which is not a replaceable relay.  When that did not work I ended up looking at the ECU controller under the seat.  When I pulled the black and gray harness off of the ECU,  I noticed corrosion.  Had I noticed this before I did anything else it would have solved my problem immediately.  The way that that harness plugs into the ECU is upside down and allows water to collect in the plug itself.  One of the pins from the ECU was even broken off in the harness itself.  I cleaned out the harness and got the broken pin out,  plugged in the new ECU controller and the machine fired right up.  I hope this saves some people out there a lot of trouble when diagnosing their unit.   Always unplug your harnesses and check the pins condition. Another pointer is don't buy one of these Chinese knockoff UTV's.  

[LeeBo]

On 4/25/2020 at 9:17 AM, PierceIt said:

Turns out the timing chain came off due to worn camshaft and sprockets. Need to replace $700 in parts.

Never missed an oil change and always used good synthetic oil. The metal inside these engines seems to be very cheap metal. 

Pretty disappointing since it only has 180 hours on it and less than 500 miles. 

My 2017 750EPS just did the same thing.   Died when running and now won't start.  Battery and starter are fine as can her the starter whirring away.  Have you has any more issues since replacing the worn camshaft and sprocket,  or did that fix it?  Assume you put in new timing chain as well while you were at it. I only have 180 hours on it.  😞

 

[dees]

I have 2017 cadet challenger 550 that fuel pump won't kick on with key but I can jump a ground wire into back of plug at pump and kicks in then but also the coil is not making fire. Occasionally but very rarely the fuel pump will come on and coil also works at the same time so will start then. Some ground issues I'm thinking but can't find where. Any ideas where or what else could be the problem. The ecu box, fues/relay box have both been replaced. The coil and regulator also new