Ok, so this problem has been going on for a few weeks now, but got significantly worse today, and i can't overlook it anymore.
My CBR 1000rr has been "lurching". In the past it was generally at lower speeds/gears/RPMs. Like, before around 35-40 MPH in 2nd/3rd gear around 3500-4000 RPMs it would start to lurch, but picking up the pace seemed to solve the problem. Until today.
It started lurching way worse than normal, and at interstate speeds. Going 70-75 MPH and having your bike jerk back and forth (lurch) is pretty scary... Anyways, I'm at a loss for what it could be.
First i was thinking maybe air filter was clogged (I've never changed it) But then I though a clogged air filter wouldn't cause that. Then I started thinking more in depth, and now, I'm thinking spark plugs, fuel pump, or fuel injectors(?)
Sorry, I'm not very mechanically inclined to bikes yet. That's what i plan on using my summer for. Engine rebuild/complete break down.

TL;DR. Bike used to "lurch" at lower speeds/rpms/gears, but now "lurching" far worse at interstate speeds (getting worse) Help?

 

What year? If it's a carbed bike, might be a clogged jet/s. If it's FI, it could be a clogged injector.
Try running some Seafoam (or equivalent) through a couple of tanks
of gas. That's the cheapest attempt at a fix. Even if it's not the solution, it can't hurt.
While you do that, double-check the fuel filter.

From the symptoms you describe, it would be unusual for the R/R to be at fault.
You might check it, just to be sure. Another possibility, a loose connector in the harness.
Just enough to allow the current to falter as road vibration affects it.
Include the battery connections in that inspection, as well.

Last possibility, a vacume leak. Check all of the hoses for cracks/holes and/or poor
connection.

That covers most of the basics. After you try these areas, then start looking at the
fuel-pump or ignition components, as the source of trouble.

Hope this helps, Ern

 

Buddy of mine just found a problem with his bike cutting out in upper RPM was a faulty sidestand switch.

Higher RPM hit the right vibrations to be making the switch just barely cut in.

Now - you said lurching is "back and forth" - you aren't meaning left to right, like this is a steering/suspension thing, right? You're saying the bike goes in a staight line, but the engine starts acting up?

 

Good points/questions adrenlyn!

Ern

 

Yeah straight line, no swerving or left and right, I'm uploading a video now. It's at night, but... you can hear the "lurches"
And thanks for the tips, both of you.

Oh, madhattr, it's an '05 so, it's FI. Also, I'm assuming all those tips you gave (check fuel filter, vacuum leak etc..) Those are all in the manuals right? Like i said, mechanically challenged on bikes at the moment ... Feel so dumb..

**edit** Oh yeah, i guess it wouldn;t hurt to mention, a couple months ago i was having electrical issues. Turns out there was a recall for my stator. Took it to Honda, they replaced it for free. And no problems since. Til this..

 

I've got the same bike. Mine has always been a pain to drive slow. One of the main issues is the rather tall initial gearing. 1st gear doesn't redline until somewhere around 85 to 90 mph, so it definately struggles at lower speeds trying to stay smooth.

One thing to check though if its recently gotten worse is the drive chain tension. These bikes tend to lurch a bit anyway, but if the tension is too loose, it will be increase the amount you feel it. make sure your chain is proplerly aligned, lubed and has the correct tension.

 

Ok, well... little (long) Upate. I bought some Sea Foam on the way home from work. Read the directions on the can, put a a little bit more than what it "suggested" into my gas tank and a smidgeon into my oil. Let it warm up to 200 then decided to leave. At first (maybe 5-10 minutes into the ride) no change, still lurching. Then i remember reading around in my endeavor to find out how to use Sea Foam, that someone said if you put it in your oil, ride it a little harder than normal to get it nice and worked in there. So, i did. Left a stop light, made it to about 70mph before shifting to 2nd and kept the rpms rev'in a little higher than what i do on a normal basis. And from that point on, it stopped lurching. The only time it kinda lurched was when i was under 4k RPM in 3rd gear going 30 MPH. But that's kinda obvious why...

So, not saying i'm miraculously cured, but... Damn that **** works good. It feels more responsive to throttle. I felt my neck kinda jerk back a few times. Have't felt that in awhile. So even if the lurching returns. I am completely satisfied with Sea Foam.
Now, i'm still gonna take a look at all the electrical that i can. Seeing as how my bike (year) has a tendency to have faulty electrics.

Speaking of... Could an improper battery cause problems like this? The owner before me installed the flush blinkers and i believe he bought another battery and put it in, and I've been told on here, that it was the wrong battery.

 

Ok, figured i'd do a final update. Well, took it to Honda, turns out the battery i had in there was barely surviving. Got a new battery, been a dream to ride since. Cranks up faster, no lurching, seems more responsive..... /sigh Feels good to knock a problem out.

 

Yay!! I love the happy ending stories. ;-)

Ern

 

Always good to check the cheaper things first, before you start diving into harnesses which if you are a "new mechanic" can cause more harm than good.

As Ern said "YAY"
And we all learned something..................