Hi all!

Recently got myself a 2002 CBR600f4i as a sort-of project bike and sort-of upgrade from my Ninja 300. Fell in love when I rode it, the power doesn’t kick hard initially, but it has plenty of juice to get you going. Great bike.

Mine was in a bit of rough shape, and one of the things that needed replacing was the cooling fan. Nbd, removed gas tank, air box, dropped the radiator and swapped the fan out, no big deal.

I start it up again to see if the fan kicks on, and now I have an FI light blinking. Nbd, shorted the diag sensor and codes were for MAF sensor. Immediately remembered that I forgot to plug in the little hose back into the sensor. Plugged it back in the next day and all was good, no FI light.

While test riding it with the FI light right after replacing the fan, I noticed the exhaust sounded REALLY good. Decel in 2nd gear sounded like a Lambo. Amazing. However after plugging the MAF sensor back it sounds fairly tame again, and no crackles whatsoever.

Half considered taking the hose back out but didn’t want to fry the O2 sensor and burn gas. Also don’t relish stalling at the gas station because I’m running lean, but also really missing the snap crackles and pops.

Any way to passively make the bike run a little rich (which is what I’m assuming caused the crackles when MAF received no air pressure) without putting in any aftermarket chips? Any of you guys have experience with this?

Thanks for reading, ride safe!

 

Welcome! I moved from a Ninja 300 as well! It made my transition fairly smooth as I didn't rev past 9-10k until I got used to it. Keep it below 6-7k and it feels just like the 300!

As for the nice crackling sound, I will say that I don't think it's something you want because it means you are running rich (someone feel free to correct me if I'm wrong!). If you just want it just 'cause, you can take off the stock bazooka and throw on a short pipe and it'll do it all day long. You will want to check your plugs more frequently as they will likely get sooty sooner. I ran like that for a few months but eventually did the "clean air mod" and it eliminated the issue but, yeah, it does sound sweet!

 

Thanks for the reply Doc,

I decided to listen to my more mature half and just keep it as it is, still sounds great. And no FI light which is always a great thing. The bike is nearly sorted, I ordered another tail light to replace the aftermarket one that's on it because currently when stepping on the brakes the LED barely brightens at all, and the coolant temp sensor is shot, so I grounded the fan to run full time until the new sensor comes in. Otherwise still a great bike and I'm enjoying every ride with it. Keeping it 6-7k will let you travel at any legal speed limit, but of course I've poked it a little past that and it's just a joy.

Sadly more poor little Ninja is getting less and less use, so if anyone is looking for a clean Ninja 300 in the Boston area definitely let me know!

Ride safe!