Thought I would share the story of how a bad starter being replaced cost me 1200 peak rpm.. Sorry in advance for the long book.
2018 Renegade 850 XRS, bought it new. At about 8000 miles, pulled off to the side of the trail and the starter failed, wouldn't even freewheel. Never even hiccuped before this. Rope started it and finished the weekend, but you could hear the starter drive dancing around against the ring gear as the engine was running.
Under BEST warranty the dealer replaced the starter, starter drive and flywheel, thank you BRP, almost $2000 canadian in parts.
Got the machine back, started fine, idled a bit choppy, smelled very rich. Wouldn't rev past 6800 RPM and a pig on fuel.
You could hold it to the bar and it wouldn't go past 6800 and eventually would misfire. I wanted it to blow up...
Removed the raves, cleaned them, re-synched them about 3 times, re-validate position, was better and would now rev to 7000rpm.
Checked fuel pressure, 48psi, checked at wot, still 44psi. Tried to blow it up again by holding it to the bar, this time I brought my laptop and candoopro.
Zero knock correction so I figured screw it, I'll bump the timing and recheck for knock correction. Did this about 3 times in 3-2-2 degree increments for a total of 7 degrees advance. Every time it got better until it now pulls 7900 RPM and runs crisp. Fuel economy is the same as the 20.5 XRS I was running with. Now I am going to actually pull the injectors and dial indicator the pto piston and set it to 28 btdc.
Moral of the story is, don't assume the accuracy of the keyway cut in the flywheel. Out 7 degrees ++. I mean, I've degreed in probably 100 camshafts for 4 stroke race engines and never found one to be out more than 3 degrees..
Hope someone else can avoid the aggravation .