Bad? Vibe Around 7k

I don't think it's been like this since I bought it, but I have a bad vibe (I think) around 6800 RPM, and seems to continue up in the RPM's. Is this normal VFR stuff, or is this something I need to get checked out?

Thanks!

 

to clarify is it a vibe that happens in any gear?
with the clutch in or out?
does the vibe occur when the bike isnt moving ?

 

Now with these questions I have to go double check lol. It happens in any gear, but it's much more pronounced in higher gears. Seems not to happen when the bike is cold.

It's SO bad I felt like the bike was going to come apart on the highway. It's honestly very scary. Now, this is under regular/modest acceleration. The vibration seems to be less apparent at full acceleration, but maybe that's 'cause I am paying more attention to the road at that point...?

 

does it happen @ 7K with the bike not moving? where does the vibration seem to emenate from? can you feel it in the bars, pegs, brakes etc?

 

Haven't checked that yet, will confirm at my lunch (at work now). Vibration is definitely through my handle bars/front fork area it seems. I do also feel it on the pegs, basically the whole bike, but mainly the handle bars.

 

what I am trying to help determine is:
If it is speed related - when the vibration occurs (and you are in a safe position to do so) pull in the clutch and let the engine return to idle - if it still vibrates the same, it's probably bike/chassis related. If it vanishes, it may be engine related.
If it vibrates as bad when not moving @ 7K, it could be engine related.

post results and lets take the next step. Also, while you are checking your bike @ lunch, see if the front/rear wheel weights are still attached.

 

Okay, vibe happens whether I am engaged in a gear, or pull in the clutch and rev to 7k. Didn't get a chance to check the wheel weights, but it's not related I am thinking since it vibes at 7k no matter what. It seems to start earlier now that I look, about 6500.

 

ugh, was hoping that wouldnt be the case.
perhaps this thread can help?
Gen 5th Engine Vibration Above 7000 Rpm? - VFR Discussion

 

another idea (possibly) is a worn/stretched chain... or worn sprockets - if you have one, you have the other

 

I was reading this thinking... "please don't let this turn out to be a 6th gen with the VTEK kicking in" . The frist few symptoms including the not doing it when it's cold were all pointing right to the early VTEK engine.


Sorry this has no bearing on your issue. It was just a funny initial though I as as I read it.

 

Blocked at work thanks to SonicWall. Awesome.

New chain to match the new sprockets (more of less teeth, I forget) that the previous owner installed. I don't see that being an issue, how would I check this?

Do you think the exhaust might be causing it? Maybe just at 6500ish RPM the tone creates that issue?

Thanks!

 

It could be any number of things, but to check the chain (at it's lowest point) is should have 3/4 to 1" of free play. Too tight is just as bad as too loose. Roll the chain on the sprockets and see if any links are deformed our bound up. Now look at every tooth on the front and back sprocket and look for abnormal wear or (!) any missing.

Could be the exhaust or even the airbox. it's tough to tell without an understanding of where the noise/vibration is coming from.

 

Thanks much! I will have my bike/race mechanic buddy check it out this week - actually ride it and let me know what he thinks. He rocks are bike fixes! I'll check the sprockets/chain tonight if I get a moment!

 

He's looking at it today during my lunch break. Hope he can find the issue.

 

In case anyone cares, per him and riding it for about 8 minutes, from speeds of 0 to 105 MPH, he did notice a slight vibe, but it wasn't enough to make him think anything is wrong. I guess this is normal? Odd lol.