Will I need to re-jet if I add a spark arrestor/silent insert?

I just placed a wanted ad in the classifieds-- I want to add a ProMotoBillet spark arrestor and silent insert to the stock exhaust system on my 2002 YZF426. I did a search and found a couple posts from several years ago in which people described a minimal loss of power and no need to re-jet after doing this modification. However, some other people reported needing to re-jet and adjust the carb in other ways after adding various exhaust changes. Just curious if anyone currently has any other info on this topic.

I just put the PMB spark arrestor on my 06 450 and I didn't need to rejet, and there was no power loss at all. I didn't get the silent insert because the stock exhaust isn't too loud. Your bike being an 02 you should replace your packing while your in there. PMB makes some packing, that they claim is quieter than stock.

As for the silent insert I can see how that would require you to rejet a little, probably lean it out 1 jet size, or possibly just adjust your air fuel screw. And it would probably cause a power loss, so unless your running in a scrable that does sound checks I wouldn't worry about the silent insert.

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