[Colezzz]

Hey everyone! So I just purchased my first motorcycle, a 2002 Ninja 250. When I first purchased the 250 it only ran with the choke on so I cleaned the carbs, the pilot jets were extremely clogged, took 10 minutes or so to unclog them. I then also checked the main jet and polished the needle seat. I put the carbs back on, removed the crumbled foam air filter as good as I could and it ran a lot better but would only rev up to about 8-10k rpm’s before stopping. I later found out that the mixture screws were turned all the way in so I set them to factory setting which improved the throttle response greatly but not the max rpm. I then tried to remove the air box lid and that made it run a hell of a lot better, it’ll actually now rev all the way up to 13k rpm but it never hits the rev limiter. What I’m trying to find out is what’s stopping it from revving out all the way and why does installing the air filter make it a lot worse regardless of engine mixture I did run it without the air filter or air filter lid when the mixture screws were all the way in and it still ran better without them than with them. Could a valve adjustment be needed?

So here’s where I’m at now, it only runs good with the air filter and air filter cover removed, as soon as I install them the max rpm lowers greatly. With both of them installed it barely runs at all and actually stalls out. The mixture screw has not changed the max rpm at all and only changed the throttle feel. It doesn’t seem right that it ran with the mixture screws backed in all the way and actually ran pretty well.

Sorry if this post seems all over the place, I wrote it at midnight lol. If you need any clarification lmk.