Surging Issue Fixed!


I have a 2007 with 43,000 miles on it. For several years now, I've been chasing a mild surging issue. The surging started between 2000-4000 rpm's when riding at a constant speed. About a year ago it slowly started to get worse; bike would surge as it accelerated until it reached 4000 rpm, and then it would magically clear up. Under full throttle though, there was no surging. For whatever reason, it seemed to be worse in 4th gear. The other issue is that approaching redline in 3rd gear, it felt like the bike's rev limiter was kicking in at around 10,000 rpms. Things I changed, either because it needed it or because I was trying to fix the surging:

1. Synced throttle bodies.
2. Replaced IAP sensor.
3. Replaced TPS sensor.
3. Replaced fuel pump/fuel filter.
4. Replaced spark plugs.
5. Had valve clearances checked.
6. Checked operation of airbox flapper-valve.
7. Had fuel injectors cleaned and flow checked.
8. Used Techron fuel cleaner.
9. Started to swap out ignition coils, with a used one, one at a time.

I know you shouldn't believe everything you read on the Internet, but I'm not a professional mechanic and I was desperate, so when I read a few articles yesterday about how a bad battery, even though charged and working, can cause problems with a bike's electrical system not sending proper voltage to the ECU, fuel injectors, fuel pump, etc., I thought, "Heh, my battery is the original 7-year-old battery, maybe...", and decided to buy a new one to see what would happen. Well, I dropped it in this morning and went for a test ride, and although I don't want to count my chickens too soon, I believe I've solved the problem. I'm not good with electricity and such, but I think what I read was that a bad battery will make demands to the bike's electrical system, even while the bike is running, to the point that the electrical system won't send proper voltage to the fuel-injection system. I'm guessing that when the bike reached 4,000 rpm's, the bike's electrical system was able to overcome the battery's needs and properly run the rest of the bike...but like I said, I'm an idiot when it comes to electricity.

Just thought I'd pass that along to anyone else having a similar issue.