So my engine has become "zingy" above 5k rpms. Its hard to describe, the exhaust note is less throaty, more high pitch, maybe more high freq vibes from the engine.

There is no power loss based on my butt dyno and accelaration from 0 to 100km/h still takes the same length on the same street. The bike starts the same in the mornings and also hot. No more nor less decel popping than always. No more or less fuel use.

The only things of notice are that I ran out of normal fuel at WOT in 6th gear doing about 120km/h on the highway on Monday. Also, the carb is gunky/yellow on the outside on the throttle cable side, all the way from the top to bottom. Wasnt like this 2 weeks ago, but Ive been riding a lot, including highway, street and very bumpy dirt rodes.

Im thinking either 1) the lean condition by no fuel at WOT screwed my cylinder/rings, but unlikely due to the power being the same and starting, 2) Carb bowl or top screws are loose and letting fuel out and air in because of the gunk, 3) very small air leak somewhere.

Im I on the right track or should I be looking at something else?

 

Does it sound like a little metallic rattle? Could be the automatic cam chain tensioner failing. A member here makes a wonderful manual adjuster. Krieger Cam Chain Tensioners

 

Nah, I know that sound all too well jajaja, but this is different, only notice it above 5k, im scared im gonna blow a ring o a rod jaja.

 

i ran out of fuel on wot few time at much higher speed...engine just cuts out and roll to a stop...never experienced a problem...everything on the bike will eventually get gunky..especially around anything that was greased...chains, cables, sprocket, etc....

not sure what this high pitch "zingy" sound is...can you maybe record it with a camera or phone?

 

Sounds like a lean jetting condition, but without any of the symptoms.

Anyway, I think it was bad fuel, from the same day I ran out at WOT, I filled up at a new gas station that Ive never gone to before. Refilled today at my usual place and the zingy noise and feeling is all but gone. Hope it stays that way.

Cheers,

 

I kept hearing these strange vibrating sounds at a narrow rpm range on my 2012 "S" and started trying to figure it out. Turned out to be the very front of the seat vibrating on the gas tank. Cut a little piece of foam and stuffed it in there. Sound gone! After a while I noticed another vibrating noise at a certain rpm range. Started searching. Found out that every thing on this bike makes a vibrating noise at specific ranges. It's called harmonics. The big noise makers are: Rear fender mud flap near shock, Front fork protectors, seat on tank, chain on guards, rear fender on sub fender etc.
Start simple. Try combos of tape and/or foam for temporary test fixes and if you find the source of the noise do something nice (cute? elegant? solid?) for the fix. It's kind of fun because it's so cheap and easy. One day you'll realize that all the little things you've done have made your bike really nice sounding.

 

On one of the 650s I had my radiator/tank shroud vibrate against the tank. It took an adjustment in the way I put the covers back on to eliminate it. Usually those spots will show by buffing off the paint on the metal if it is a piece contacting painted metal.

 

You know what, now that I think about it, I was doing something (idr what) and afterwards around 5k rpm there's a little tinging noise, probably a loose bolt, part, etc that when the bike vibrates the part hits something. I'm sure it's nothing to worry about though, unless it effects engine performance

 

Klx 678 nails it. A vibrating part will show abrasion marks/witness marks. I think it's worth fixing. Little vibrations turn into bigger vibrations, elongated holes, loosened bits and shed parts. OH THE HUMANITY! Don't shed! Anything!

 

I figured out my buzz by pressing against panels until it stopped. That's how I figured mine out. Right side shroud was buzzing against the tank. I have to press the panel when tightening the fasteners to get it up tight. Could have probably put a very thin foam strip in there, but I didn't have the stuff when I was dealing with the problem.