Serious Vibration, related to engine speed

[Pleasegivesoap]

Hey guys, I've got a problem
I've got an 01CBR600F4i, 15k miles, been running pretty good. I rode it maybe 20 miles a day on average up until about 2 weeks ago - stopped riding for 8 days or so, cause i needed to tighten/lube the chain. Finally got on the bike three days ago, went to lube/tighten the chain, noticed some vibration through the bars and tank-at first I thought it was the chain. Finished w/ the chain (it's a bit tight tho), and still, vibration!

I rode 120 miles from Great Barrington, MA to Poultney, VT yesterday, and the vibration was a BITCH - thing is, it's related to engine speed: If I'm clipping along at 60, pull the clutch in, rpms drop, vibration stops. It's completely linear: higher the rpms, more vibration. Also, similar to a post a while back about wheel wobble, if I take my hands off the bars at 40mph+, it slows and wobbles slightly (1/2inch bar travel maybe) - with the vibration.
HELP! I have no clue what this could be - it wasn't dropped, or anything, this is out of the blue.

Any ideas? I was thinking something like loose bearings, but it has to do with engine speed, so...

---Also, I'll be in Upton, MA (right next to Worcester) for the next week - is there anyone around that area that would be willing to take a look and give me their opinion?

Thanks,
Eli

[ZX-12R]

What condition is your chain and sprockets in?

Another simple thing to do is inspect and re-torque all of your engine mounts.

[Pleasegivesoap]

Chain and Sprockets are brand new - 800 miles on both - but it has to do with engine speed, not road/wheel speed.

Engine mounts...hmm - I'll do that when I can, but I'm not sure how something could have loosened when it was just sitting in the driveway for a week.

[Degsy]

Eli,

Run it for a short time on idle and feel the exhaust headers (carefully) as it warms up. Check to see that they all get hot. You might be only running on 3 cylinders.

derek

[Pleasegivesoap]

I thought that might be it, but was debating on how to check - well, I did that, and it hurt a bit. Weird thing is, all 4 heat up at a decent pace, getting gradually warmer, but the 3rd one (3rd from left while on bike) heated up much much faster, to the point where I could touch the other three and they'd be pretty hot (not hot enough to burn if I would touch briefly) but the 3rd from the left was blistering. What does this mean you think?

Also, about the wobble, I got a flat in NH yesterday, luckily next to a garage - they plugged it, and I borrowed their torque wrench and realigned the rear wheel, inflated both to correct psi (the front was at 24 instead of correct 32), and that helped a bit, but still, same thing. I am positive that the vibration (and lack of performance I'm finding, hence the thought I was running on three cylinders), is due to engine speed, not road/wheel speed. if It's idling while parked, I can rev it to 6k and still feel the vibration climb as if I was on the road in 6th.

Any other ideas? what do you think the third header heating up way faster than the other three means?

Eli

[Karaya One]

If you tightened the chain and then you have vibration - checked the chain and all is fine.

I would look at the countershaft sprocket - make sure its straight and on the bike straight and then the shaft bearing itself. If the bearing was bad, you would get serious movement there.

[Pleasegivesoap]

if it was the countershaft sprocket, wouldn't I feel vibration rise/fall due to road/shaft speed, not engine speed? Even if it's idling in the driveway, and the clutch is pulled in, not moving at all and I rev it, the vibration's there.

hmm...

Oh also, this may be relevant: every once and a while (maybe 2-3 times since I've had the bike) I'll be shifting under power, and I'll miss a shift from like, 3-4 or 4-5, and it'll act as if it's in neutral (no power to the wheel), but since I was giving it throttle, the revs climb a bit, then go back down. The thing is, if that happens, I can hear like, pinball happening inside the engine/tranny (sounds like a tiny screw or two bouncing around in there). The revs will fall, I'll shift correctly, and that's it - no change in shifting, performance, slippage, no sound, nothing. Weird... anyone know what that sound is/what I've done?

[Degsy]

All together now...."camchain tensioner lifter!!"

just a guess.

[keeena]

All together now...."canchain tensioner lifter!!"

just a guess.

My friend has an '02 F4i which had a bad CCTL. Common problem, but I'm not sure it would cause this guy's symptoms. My buddy's bike didn't have vibes, just an annoying rattle noise right around 5k RPM. Its not too expensive to fix, but a little bit of a pain in the ass to get to. Plenty of info on CBR forums...just lookup CCTL (or CCT).

The wobble could be worn front tire (cupping) or steering stem bearings? From your description I'd guess that its unrelated to the motor vibe you're getting.

You said your drive chain is on the tight side; adj it to factory specs. What is the valve clearance inspection interval for that bike?

[Paul_E_D]

The wobble is just from running Dunlops

You might have a bent or burnt exhaust valve.

[Crash Dummy Denno]

the title of this thread is funny


its probably your alternator

[Pleasegivesoap]

OK, so
1. Bent/burnt exhaust valve,
2. engine mounts
3. camchain tensioner lifter
4. alternator (why would this be the problem?)

Any other ideas?

[Billy]

Hey,

I had a 1999 CBR 600 F4i as a first bike with 10,000 miles on it when I bought it. It had the exact same problem. The vibrations wasn't as severe as you are describing. Turned out to be the cam chain tension lifter.

I got it replaced with a manual cam chain tension lifter and problem went away.

[TLRMan]

Yeah..what he said....

[v2winstunter]

I don't know. My cam chain tensioner was just loud. It didn't cause any serious vibrations. But it also only made noise from about 3.5 to 5K RPMs. Maybe yours is really bad?

[rebelpacket]

You might have a bent or burnt exhaust valve.

+1

A serious vibration like that means something is terribly out of whack, or about to fall off, or something terrible already happened. Does the bike feel down on power? Try a compression test? Check countershaft endfloat/runout? Are all your valves at the proper clearance?

P.S. Rather than try and "feel" the headers like Degsy mentioned, take some WD-40, and just spray it on the headers when their hot. Achives the same goal, with less chance of removing your fingerprints.

[KB]

+1

A serious vibration like that means something is terribly out of whack, or about to fall off, or something terrible already happened. Does the bike feel down on power? Try a compression test? Check countershaft endfloat/runout? Are all your valves at the proper clearance?

P.S. Rather than try and "feel" the headers like Degsy mentioned, take some WD-40, and just spray it on the headers when their hot. Achives the same goal, with less chance of removing your fingerprints.

Daon't listen to this guy. Look at his avatar he rides on the road with his foot out MX style.

KB

[rebelpacket]

I don't ride foot out. I just keep trying to kick your ass, and I keep missing.