Renegade 600 backfired on startup

[b1scu1t]

My dad's Ski-Doo Renegade 600 is acting up. We just put in a new stator, injectors, and ECM before the season.
Last night, it backfired on startup, then later, it started running poorly and quit after about 10 minutes, with the temp hitting around 150F.

Now, it'll turn over but won't really run, and it needs to cool down for a while before it'll even try again.

No check engine lights or codes. It's always run a bit warmer than our MXZ, too. Could it just be a fouled plug, or are we looking at something worse, like engine damage or a bad thermostat? Any ideas?

 

[rd4d_123]

Are you doing some off-season testing? Anyway, while checking and swapping plugs is always a good first step, how you describe it suggests something beyond just a fouled plug. It sounds more like a fuel delivery or ignition issue that's getting worse with heat or potentially a crank sensor acting up. A bad thermostat usually just causes overheating, not necessarily the shutting down and needing to cool off to restart. I'd recommend looking at fuel pressure under load, coil integrity, and double-checking all electrical connections, especially grounds that might be sensitive to heat.

 

[SkiDavis_]

My dad's Ski-Doo Renegade 600 is acting up. We just put in a new stator, injectors, and ECM before the season.
Last night, it backfired on startup, then later, it started running poorly and quit after about 10 minutes, with the temp hitting around 150F.

Now, it'll turn over but won't really run, and it needs to cool down for a while before it'll even try again.

No check engine lights or codes. It's always run a bit warmer than our MXZ, too. Could it just be a fouled plug, or are we looking at something worse, like engine damage or a bad thermostat? Any ideas?

What @rd4d_123 said is plausible but my first thought was to double-check the timing, especially since you just replaced the stator. It's easy for that to be off a tooth, and that would definitely cause a backfire and poor running. That warmer running temp is also a bit of a red flag, and 150F after just 10 minutes is definitely high for a cold start. A fouled plug is possible, but it's more of a symptom than the root cause here. I'd pull the plugs and see what they look like, and then check that stator timing again. It could be a bad temp sensor, or maybe even a clogged coolant line, but I suggest to start with the simple stuff first.

 

[Skibby Doo]

Isn't it ridiculous that a 600 Renegade can fail catastrophically with no codes or warnings, showing how poorly Ski-Doo balances advanced electronics with basic engine reliability?