• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

2017 Mountain Cat won't start

B

BWhitty

Member
Dec 7, 2019
17
6
3
SUCCESS! Thanks to my local dealer in Salem OR for pointing me in the right direction.
He said he'd had one last year with stuck power valves causing a voltage spike which blew the ECU and was causing the same issues.. That was the only other thing he could think of besides parts I'd already replaced. I set the power valve cables to spec and the machine fired right up.
 

spoon

Wrenching to ride is half the fun
Lifetime Membership
Dec 2, 2007
1,236
642
113
53
Kootenays, BC
Knowing what caused this I would pull the power valves and check for the edges rubbing the piston. Common issue with these as well. I ground mine back on the corners to prevent it after seeing the rub/wear marks on my pistons.
 
B

BWhitty

Member
Dec 7, 2019
17
6
3
Knowing what caused this I would pull the power valves and check for the edges rubbing the piston. Common issue with these as well. I ground mine back on the corners to prevent it after seeing the rub/wear marks on my pistons.
I've never heard of that- thank you.
 

MI1M600EFI

Well-known member
Lifetime Membership
Premium Member
Nov 15, 2008
298
117
43
51
Mancos, CO
And thanks for following up and publishing the fix!!! Nothing so depressing as finding someone who had the same problem as you several years ago who was too lazy to let us know how they fixed it.
 
B

BWhitty

Member
Dec 7, 2019
17
6
3
Just got back from my annual trip. Rode 2.9 miles down the trail and it died while traveling to our spot.
Towed it back to the truck and worked on it that night after riding a back up sled.
Once it died I notice the pull start wouldn't engage. Ended up finding the lever from the pull start that engages the flywheel in the bottom of the sled. There was no visible damage to wires or the flywheel.
Fortunately, I took all of my tools and spare parts with me. 5 hours of work that night replacing the stator and timing sensors yet again and she fired right up and ran for the rest of the trip. There were no obvious signs of damage to anything, but I assume something took a hit from that piece.

Part way through the 2nd day the fuel sensor quit working, and the gauge won't show the voltage. Not sure what's going on there, but at least she runs well.
 

MI1M600EFI

Well-known member
Lifetime Membership
Premium Member
Nov 15, 2008
298
117
43
51
Mancos, CO
Man, you just can't catch a break...

I replaced the stator in my M8 turbo, thinking it was weak. New stator (From Caltric) had no effect on starting. Finally figured out that powering the turbo oil pump from the fuel circuit the problem. A year later the Caltric stator failed at the worst possible time on a ride. At least my friends were there to pull me back to the truck. I put the original stator back in and it's still going strong. If you put a Caltric stator in it, I'd look for a spare OE stator to take along on multi-day trips... It was pretty obvious that mine was barley soldered on one connection, and once the connection burnt out, there wasn't enough wire sticking out to fix it, though I tried...

Fuel sensor and voltage seem related. Check the cluster connectors for water/corrosion. ?
 

spoon

Wrenching to ride is half the fun
Lifetime Membership
Dec 2, 2007
1,236
642
113
53
Kootenays, BC
I've heard from a good source that Rick's does a good job on Cat stator rewinds. I have a weak OEM one that I'll be sending to them to rebuild.
What was your symptom of "weak"? I have 2 sleds with intermittent electrical issues and always looking for other possibilities. 1 had stator changed and little difference (quits when heat soaked) other 1 won't stay running at low rpm when hot but can no longer duplicate since that ride. Have a few ideas but open to others.
 

boondocker97

Well-known member
Lifetime Membership
Oct 30, 2008
4,092
2,829
113
Billings MT
What was your symptom of "weak"? I have 2 sleds with intermittent electrical issues and always looking for other possibilities. 1 had stator changed and little difference (quits when heat soaked) other 1 won't stay running at low rpm when hot but can no longer duplicate since that ride. Have a few ideas but open to others.
I was getting my temp light to flash at me even in deep snow. Never had the issue before and did a top end just prior so was sure it was air. It wasn't so I changed the thermostat. Same problem. I had suspected a fuel issue going back before this so I plumbed in a fuel pressure gage I could watch by the regular gauge. When I open the throttle wide open the fuel pressure would drop. Checked voltage and it dropped a bit instead of increasing when increasing rpm. Ohmed the stator and the fuel pump circuit was out of range compared to the manual. Changed stator and fixed it.

Also found a bared wire behind the chain case that was probably causing an intermittent no-start.

On stators Jason Nethercott said they had running race sleds that would pull 2-3 grams more weight by swapping stator for a new or rewind one.
 
Premium Features