Hey all, I have a '99 CBR F4 that I bought about a month ago. I bought it in inoperable condition (needed a new battery) so i swapped in a new battery, and took it to a bike shop to get a minor service and make sure everything checked out ok. 2 weeks after I swapped the battery, I got some sort of power problem, the dashboard lights were flickering (same with headlights and taillights) and it would stall at intersections. I could restart it but I had to turn the idle rpm up a little and rev a bit before letting out the clutch in 1st gear, otherwise the bike would stall. I looked it up on the forums and the regulator/rectifier seemed to be a common troublemaker, so I swapped it out for a new one just now. Took the bike for a spin to charge the battery (~30 minutes of freeway riding) and when i exited the problem still persisted, flickering lights and stalling unless I kept the rpm above 1.5k during idle.

What else could be causing this problem? I'll probably end up just taking it back to the shop to get it checked out, but I want to see what you all think too.

 

..sounds like the battery isn't charging. When you keep the revs up it's enough to run everything but when you need to draw from the battery there's nothing there. I'm not sure which one is more likely but I think the two things to check first are the stator and the regulator/rectifier. The RR is easy to disconnect and check across the terminals with an ohmeter. I've replaced two of those (an F2 and an F3, got my fingers crossed on the F4!), but I've never done a stator.

 

+1, most likely is the R/R

 

Well like I said, I replaced the R/R and the problem still persisted. Maybe the something wrong with the stator then? Or a connection problem? I ordered a multimeter online so maybe that'll help me determine the problem.

Thanks for the feedback, guys!

 

I know it's easier to swap and try other parts - but where did the other R/R come from? It's such a common problem that one could be bad too - unless it's brand new. They only way to eliminate that as a problem for sure is to test it with your new mm. The manual is pretty clear about how to test both the R/R and the harness. If they're okay, then I would move to the stator.

Good Luck

 

The R/R I swapped in was brand new, so I'm pretty sure it can't be a problem. I'm getting a battery tender to juice up the battery again, maybe that'll solve the problem? The bike was low-sided on the left by the previous owned, there's rash on the stator cover. Do you think the stator could've been damaged?

 

Mine was in a crash a few years back. Test the stator when you get the meter. Also verify the battery leads are tight and all ground connections are tight.

 

I will do that when I get my mm. Thanks for the input everyone!

 

Just checked my bike again, turns out the positive lead on the battery was loose, so I tightened that up. Gonna take it for another spin see if the battery charges or not, keeping my fingers crossed!

(If that really was the problem, I spent so much extra money getting a new R/R, mm, battery tender, etc. but hey, I guess it doesn't hurt to have those, right?)

 

Yep, it was the loose positive lead on the battery. Once I tightened it and turned on my bike, the flickering was gone. Rode it for a good hour just for fun thanks all for the advice!