Now it's my turn to step up and benefit from the data base.
The 800 has become obnoxiously loud and rambles on in downhill coasts and I pulled the spark arrestor and tip, and lo, the screen has rotted off. I fished the end bit out of the muffler. That's got to be only part of it because I cobbled up a temporary screen and it does nothing to quell the racket.
I capped the tip with my hand with the motor idling and while it got way more quiet, it no way seems to build the pressure it should so I need to go further in. Donuts are probably toast and I'll order those moose springs if I can from Canada.

I doubt the guts in the can are rotted but if they are, has anyone toyed with these mufflers?
https://www.gseperformance.com/product/cf-moto-zforce-800-trail-tamer-muffler-21100/
I'm not buying the performance gains claim (exactly how would it gain performance?) and I don't want anything that's  much louder than stock.

I have an idea the springs, donuts and spark arrestor will get me back to stock sound and operating, just musing on my options.
Thanks for the thread.

[2015 Z Force 800 53/Trail EPS]

Wow..that's a first for me. I do know if it won't build pressure with your hand over the end it's leaking somewhere. Mine had pushed-apart a joint and was set cock-eyed and leaked bad. The springs had stretched enough that even after re-setting it it would still leak even with a good donut. Hence the springs. Not a bad price on the muffler. Looks like you can just buy a new spark arrester for about 26 bucks though.

Yeah that's (surprizingly) Alpha Sports price too!
I tried ordering it locally but they say they get stock from the USA and no answer yet in over a week. May have to go Alpha and their awful shipping fee.