· Super Moderator
2008 YZF-R125 (180cc)
Most likely not an issue since it will certainly have an O2 sensor so however the breathign characteristics change it ought to just adapt back to stoichometric/14.4:1
exactly. Tbh I write the full explanation not just for you but for whoever googles it in future and ends up on this page and so that the next person who asks it can just be referred here. It's taken a LOT of time and effort to piece this info together and test it etc over the last couple of years since presumably mechanics don't really wanna tell folks too much bc it's their income and there's a lot of just garbage/misinformation info out there too.> So long story short, the exhaust and filter will require a tune for maximum gains. But without the tune, the bike will still run perfectly fine without risking any long term damage ?