Idle

On My 80 KZ650 E with Idle adjustment screw back all that the way out. The engine idles at 2000 rpm

Has it done this ever since you owned it, or is it possible this began after someone had the carbs off the bike to work on them? If someone had the carbs off the bike and did a bench sync (or other work), they may not have centered the idle adjuster before setting the height of the slides. This can be corrected without removing the carbs. The idle screw needs to be turned in several turns (as if setting the idle higher) Then all the slides needs to be lowered the same amount as each other until the idle is close to where you want it. At that point the idle screw can be used to fine tune the idle setting and then the carbs need to be synchronized.

If that is not the case, it is possible you have a vacuum leak, perhaps the carb holders are leaking. Let us know if you need instructions on testing for that problem. Ed

I Sprayed the intake boots with carb cleaner last night and it does result in the engine speeding up.. would that be a definite indication of a vacuum leak?

Yes. Any change in the idle speed when you spray the carb holders indicates the carb cleaner is being drawn into the carbs. The only way that can happen when spraying the carb holders is if they are leaking and letting air enter. Ed

it does the same thing when i spray the boots from the airbox to the carbs.. is that as critical?

Sounds like you have leaks for and aft of the carbs.
Not as critical between the carbs and airbox, although you don't want unfiltered air coming in.

Is there any danger to the rubber by spraying carb cleaner at it? The stuff seems pretty harsh!

Carb cleaner won't hurt the carb holders. If there is any excess that doesn't evaporate, just wipe it off with a rag, but try not to get it on your skin. Ed

I ordered new boots... any advice for installing them?

Assuming your bike currently has the original carb holders on it, take a look at the following information. The carb holder screws can be REALLY tough to loosen, but if you use the info below they are easy to remove and re-install. The carb holders do not need any type of sealant, they go on dry, but it wouldn't hurt to put a little anti-seize on the screws before tightening.

Before reaching for that Phillips screwdriver to do a repair or maintenance PLEASE do yourself a big favor and visit the following link. It explains the fact that Phillips screwdriver tips will wreck the crosshead screws (they are not Phillips - they are JIS screws) on your KZ650 and tells how to easily deal with this issue so it will not be a problem.

kzrider.com/forum/21-tools/532335-budget...ewdriver-tips#532335

Consider buying a can of Kroil penetrating oil and use it to soak stubborn fasteners SUCH AS THE CARB HOLDER SCREWS for a couple days before trying to loosen them. Remember, the original screws and bolts were installed on your bike when Jimmy Carter was President, so many of them may be hard to remove. Kroil can be bought online ( www.kanolabs.com ), at guns shows, and at some other venues. Ed

Could pb blaster be used in place of the kroil?