Im hearing a high pitched chirping noise when Im running about a quarter throttle, only while moving. Any ideas.

Are you using a supertrap style (Stacked disc) silencer?

no, I have a DR.D slip on. The only other mods are jetting and K&N. Im also losing horsepower - only a little though, but my wifes stock Z400 is a little faster.

Any friction noticed when coasting? Any noticable amounts of metal shavings or clutch material in the oil when you change it? Is the chain tightened to spec or too tight?

still need to change the oil, just got back from G yesterday evening, if there is any of that stuff, what does that mean??? There does seem to be friction while coasting. Chain is fine.

That just gives you an idea of where to look. I am trying to help you trouble shoot and rule out the simple things.

Did you change anything right before you noticed this or did it start on it's own?

Sounds like a bearing or bushing needs to be lubed, swingarm pivot bolt, seized rear hub bearings, shock linkage/pivots. Also I have seen brake discs, most of the time the rear warped/bent just enough not to notice while riding and every time it goes around the high spot makes the brakes sqeak alittle. Some bikes have chain rollers that sound like that as well, but I don't remember if the LTZ has one or just a slider.
I don't know what year the bike is, but I know Suzuki and most manufacturers are pretty liberal about the grease they put on the bikes and the dealer during prep does not even touch these areas because they are already almost completly assembled when they get them. Just grease all the pivots/bearings and see if that helps.
Good luck.

The rear disk is famous for warping.
You should be able to tell where the noise is coming from. Front, middle, or rear while riding slow.
Change the oil and take a look. Make sure the motor is good. then go from there.

It is also common for the parking brake to stick on the bike. Might want to check that out too.


FUELATV

Sounds like a brake pad rubbing.

I doubt if its in your engine, but have you checked your valve clearance and timing chain tensioner. You should have 2-3 clicks left in the tensioner.

jack up the rear swing-arm and try and move the axle. there should be NO play in it! i just had to have my carrier bearings replaced, and from what your discribing, thats exactly the same noise mine made when they died!!!