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2017 Mountain Cat won't start

B
Dec 7, 2019
16
6
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I took the machine out a few weeks ago the day before an ice storm hit our area (OR). It started the second pull from cold every time, and the first pull when warm.
I left the cat on my sled deck during the ice storm for about a week. She started right up after that week and I pulled it off the truck. While driving it towards my shop it would start beeping like it wanted to kick into reverse a couple of times so I had to either push the button or hold it (can't remember).

During my ride, I noticed the starter motor gear lying under my clutch and figured out why my electric start quit working on my last trip. I didn't look into it back then since it started so easily with the pull cord.

Since I had the time and the gear in my pocket, I figured I'd re-install the gear while the weather is garbage. Both snap rings had come out, and I was able to install new ones without pulling much apart. I just had to remove the rubber boot at the tie rod and pull the hood.

Since this repair a few weeks ago, my machine has been dead.

Compression is at 150psi.
Fuel pump pumps up to 41psi or so and then drops after I pull (I think this is normal?)
Spark is good at all plugs.
Pipe is pulled for this diagnostic work --- will the pipe being removed be the cause of any issues?
With plugs removed, it pulls over easily.
With plugs installed and machine cleared of gas it will pull over once easily, once semi easily, and a third pull is very difficult. Sometimes on the third pull, it will backfire and sometimes start for a half a second. I then have to pull the wires from the fuel injectors and pull many times until pulling becomes easy again.

I bench tested the injectors and they seem fine. With power when pulling, they inject fuel on the 2nd pull but not the first. I'm guessing this is normal? With no power--injector wires removed they don't inject fuel as I would expect.

Since it gets hard to pull only after trying to start it, I'm wondering if the bottom end is flooded. I currently have the machine flipped upside down and tied to my shop rafters to drain anything out of the bottom end.

I can pull the dang thing not stop and it pulls very easily with plugs removed. This, along with the good compression leads me to believe there's no engine issue.

Any ideas? I have an annual trip planned in two weeks that may be cancelled if this isn't fixed. I currently have a new fuel rail and injectors on standby, a new ECU, and new fuel pump. I mass ordered just in case I could track down the issue.
 

MI1M600EFI

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Sounds like it's locking from fuel but there's no way it's dumping that much fuel through the injectors during the short time that you're pulling it over. Anything running out when you pull it over upside down? Kudos to you for thinking to strap it to the rafters!!!

I've seen the oil lines bleed oil into the crankcase but they usually still start, they just smoke a LOT for a while... If an injector stuck open, and the tank was full, it could have bled fuel into the crankcase. You should see gas blowing out if you pull it over with the spark plugs out... Especially if it's upside-down... ??

The starter having or not having a gear should have nothing to do with it not starting when you pull the rope... Did you cut any wires or leave anything unhooked after working on it?

Sounds like it's injecting fuel but just not starting... Not sure what would cause that... Timing issue? Check all connectors for water and blow them dry if you find any... ???
 
B
Dec 7, 2019
16
6
3
Sounds like it's locking from fuel but there's no way it's dumping that much fuel through the injectors during the short time that you're pulling it over. Anything running out when you pull it over upside down? Kudos to you for thinking to strap it to the rafters!!!

I've seen the oil lines bleed oil into the crankcase but they usually still start, they just smoke a LOT for a while... If an injector stuck open, and the tank was full, it could have bled fuel into the crankcase. You should see gas blowing out if you pull it over with the spark plugs out... Especially if it's upside-down... ??

The starter having or not having a gear should have nothing to do with it not starting when you pull the rope... Did you cut any wires or leave anything unhooked after working on it?

Sounds like it's injecting fuel but just not starting... Not sure what would cause that... Timing issue? Check all connectors for water and blow them dry if you find any... ???
Thank you for reading my jumbled mess :) I swore it was locking from fuel/ oil, but it only injects that tiny bit of fuel on the second pull, and then the third pull becomes hard to very hard. A buddy thinks I have some sort of timing issue as well. Not sure what to check there unless it's the ECU?

Virtually nothing has come out from the bottom end while hanging upside down. I'd guess a tablespoon tops. It did smoke quite a bit for a while on my one trip I made before this issue arose. I assume any of the oil in the bottom end burned out since the exhaust went from dark black to cleaned up as I rode.

Maybe I'll just throw in the brand new ECU and injectors I picked up from ebay and see what happens.
 

boondocker97

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If the reverse button is stuck or shorted out after it got water in it from the ice storm that might explain the timing problem...continuous state of trying to retard the timing once it senses the motor spinning? I would try to unhook the wires in that cluster and see if it changes anything.
 

MI1M600EFI

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Oil or gas in the crankcase isn't going to just run out with the engine upside down, it's just going to pool in the pistons and cylinder depending where the piston is... I don't think this is your issue anyway, as when the crankcase gets flooded, if you pull it over without the plugs it'll blow a mist of oil/gas out the plug holes... I assume you are not seeing that, and if you are, then use the starter and roll it over until it stops blowing mist...

I think Boondocker is onto something... I think timing is your problem, and most likely cause is the reverse button. The beeping while riding is a good indicator that something was going on... If your shop has been cold, it may still be frozen or shorted by water... Unplugging it isn't terribly fun but it's not that hard either. You will need a T9 torx driver for one screw though. Definitely worth making sure the switch isn't somehow stuck... At least disassemble the RH switch pod and blow it out or put a hair dryer on the it to dry it out for a while?

You could try the ECU since you have it but I don't think ECU failure is common... Your tests indicate that the injectors and fuel pump are not the issue, as you're getting fuel.
 

sno*jet

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Dec 13, 2007
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I was in my manual other day and noticed a note in bold that said not to pull motor over without plugs grounded or it can damage the coils. Wonder how many people ignore this. Anyway I know these sleds sometimes need to thoroughly dry out when moisture gets in them
 
B
Dec 7, 2019
16
6
3
If the reverse button is stuck or shorted out after it got water in it from the ice storm that might explain the timing problem...continuous state of trying to retard the timing once it senses the motor spinning? I would try to unhook the wires in that cluster and see if it changes anything.
From what I can see, the reverse switch is a sealed switch. I have an aftermarket harness that came this way when I bought it. The wires run down into the main harness . I already tried to see if I could unplug it and failed to find a spot to do so. I ran a heat gun on the switch hoping moisture was causing the issue. The machine is so far torn apart now, I won't know if that helped for a bit.
 
B
Dec 7, 2019
16
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Update: I tested the pickup coils. They are in spec at 183.3/ 183.8 ohms.
I unplugged the harness that goes to the handlebar stuff (kill switch, reverse button, etc.)-- same results.
Third pull and it backfired/ pulled back on me and sprained my wrist for the 2nd time in the last few weeks.

I pulled so much I now need to replace my pull cord-- it tore after many pulls this evening.

As a side note, I'm not able to cut power to the injectors with the throttle and have to pull the wire to the fuel pump in order to cut power and unflood the machine. I'm guessing the TPS is what sends the signal to cut power to the injectors?
 
B
Dec 7, 2019
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FUEL PRESSURE QUESTION:

I disconnected the fuel line at the pump a while back and got around 42psi when attempting to start the machine.
The second I stop pulling to try to start it, the pressure drops off quickly down to I think 20psi.

Should pressure always be built up in the line between the pump and injectors?
 

boondocker97

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When I had a gauge cut into my fuel line it would drop to 20-30psi when the sled shut off.

Unplugging the fuel pump is how I always heard to kill the fuel supply.
 
B
Dec 7, 2019
16
6
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When I had a gauge cut into my fuel line it would drop to 20-30psi when the sled shut off.

Unplugging the fuel pump is how I always heard to kill the fuel supply.
Just to verify, with the machine off, pressure should stay built up to around 40psi?

I don't have a leak and am wondering if there's a check valve issue or if it's normal for pressure to not stay up when the machine isn't turning over or running.
 
B
Dec 7, 2019
16
6
3
When I had a gauge cut into my fuel line it would drop to 20-30psi when the sled shut off.

Unplugging the fuel pump is how I always heard to kill the fuel supply.
Disregard my last post. I just re-read what you wrote and I misread what you'd written the first time. Thank you for the verification.
I couldn't figure out how to delete my previous post- my bad.
 

Old & slow

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Update: I tested the pickup coils. They are in spec at 183.3/ 183.8 ohms.
I unplugged the harness that goes to the handlebar stuff (kill switch, reverse button, etc.)-- same results.
Third pull and it backfired/ pulled back on me and sprained my wrist for the 2nd time in the last few weeks.

I pulled so much I now need to replace my pull cord-- it tore after many pulls this evening.

As a side note, I'm not able to cut power to the injectors with the throttle and have to pull the wire to the fuel pump in order to cut power and unflood the machine. I'm guessing the TPS is what sends the signal to cut power to the injectors?
When it backfired was it the exhaust on intake? Intake is a sign of a timing issue exhaust is a sign of a fuel issue.
The ecm controls the signal to the injectors, the tps will be one of the inputs the ecm uses to determine duration.
Double check your hood harness for a bent or corroded pins.
I am leaning toward what BD97 said about the reverse switch. I would try to bypass or unplug as much as possible always leaving one way to kill the engine and see if you can get it to run. Remember it may now be flooded from all the pulling so you have to treat it that way when trying to start it. If possible it should to on a stand as I have seen them run away when they are full of fuel.
 
B
Dec 7, 2019
16
6
3
When it backfired was it the exhaust on intake? Intake is a sign of a timing issue exhaust is a sign of a fuel issue.
The ecm controls the signal to the injectors, the tps will be one of the inputs the ecm uses to determine duration.
Double check your hood harness for a bent or corroded pins.
I am leaning toward what BD97 said about the reverse switch. I would try to bypass or unplug as much as possible always leaving one way to kill the engine and see if you can get it to run. Remember it may now be flooded from all the pulling so you have to treat it that way when trying to start it. If possible it should to on a stand as I have seen them run away when they are full of fuel.
I believe it's backfiring on intake, but need to figure out how to be sure.
There is no TPS with this wiring harness. Last night I disconnected the harness that controls the handlebar controls including the kill switch and reverse switch with no change.

Thank you for the tip regarding putting it on the stand. This is definitely something I overlooked.
I'll just have to unplug the fuel pump wire for the kill switch if needed while I bypass as many items as possible.

I ordered ebay take off pick up pick up wires and a stator. I'll try to figure out how to swap those out and hope this is the fix. I'm down to 9 days before the big trip and am crossing my fingers.

On the third pull after the engine has been cleared, I can only get about a quarter pull before there is a fairly violent pull back on the pull rope. I had to quit attempting to use the electric start since it was damaging the gears.
 

Old & slow

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I have a similar situation where the recoil is pulled out of your hand. I did get it to fire up briefly and the engine was running backwards. It on a old sled but its the same problem. I do know there is a timing problem. I think you are somehow stuck in reverse mode. I am not familiar with the push button start but from I can see is the reverse button is also the start button. If that is the case something is buggered in the switch or ecm. That switch should send a signal to the ecm to either adjust timing to reverse the engine or to start the engine, all based on inputs in to the ecm. Your e start is working so I would be leaning towards the ecm or connectors on the ecm or inputs to the ecm. By unplugging the start reverse switch you should have eliminated that part. Check over the harness for damage and the connectors on the ecm for moisture or corroded pins, dang this is a tough one good luck!
 

spoon

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I have seen flywheels go out of time by outer part moving on hub. Does the exact same thing you are describing. Sheared flywheel key can also cause this. Remove the flywheel and check the key and see if any signs of movement from hub to outer magnet ring. Compare keyway orientation to outer timing tabs with a known good flywheel. Even comparing to a Suzuki one will tell you if it is off. Just for HaHa sake, wrap a strap around clutch backwards and see if it starts.
 

Old & slow

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I have seen the fly wheel key break on the 1000 before for sure, could be the issue here as well. It would sure explain some things if that is the case and an easy fix!
 
B
Dec 7, 2019
16
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I talked to a small engine mechanic who mentioned the flywheel key as well. I'll be pulling the flywheel in a couple of days.
At top dead center, the timing mark aligns with the biggest mark on the flywheel as viewed through the port. Not sure if that means it won't be the key?
 
B
Dec 7, 2019
16
6
3
Update:
I replaced the following:

1)New ECU
2) Pick up coils and stator from 2017 m8000- ebay
3)2017 fuel injectors and fuel rail replaced from e-bay
4)Replaced fuel pump

All wires check out good. I've checked the entire harness as good as I can.
No signs of frays, singes, pinches wires, etc.
Spark is perfect on all 4 plugs.

Any other ideas? I figure the timing can't be an issue although it's still wanting to rip my arm off. The only interesting thing is that once I replaced the ECU it didn't try to rip my arm off for a while and kept trying to fire. It ran for about 5 seconds at one point before going back to its old ways.

I'm ready to go back to a carb'd machine at this point.
 

Old & slow

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Do you have a service manual? If not Country Cat has online manuals that should help with the troubleshooting. They do tell you what and where to measure and required results. If you are not familiar with these manuals just be aware that it will have specs for more than one model so you need to make sure you are using the right model. You can find them under technical info at the top of the home page then use the filter to get to the service manual and proper year.
 
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