idles like a banshee

I finally got it running, well, kinda. I started it up with the choke ran it 5-10 mins it would rev up on it's own to redline a few times so i'd kill it before it destroyed itself and start it again. i let it warm up 100% and now it runs like an banshee the minute you start it up so you have to kill it right away. where could this problem lie? its obviously getting too much air/fuel to be running so crazy. i took the airbox off so there are no filters on the carbs (it's easier to pull the carbs), would that do it?

i don't know anything about carbs really. could something be stuck open? there is also a hose that goes to the airbox that comes from a vacuum cannister just behind the head tube, vacuum lines from #s1 and 4 carbs go to it as well. because the airbox isn't installed the tube is just hanging there, does could that effect the idle?

what do you think a shop would charge to get it running correctly again?

You may have already checked this, but I've made this mistake a few times, so it is worth going over again.

You should take a look at your idle adjust screw in between the second and third carbs so make sure it isn't turned in too far. If this thing is too far tightened, it'll cause a really high idle like that, but it'll only really show when the bike it starting to warm up.

Could be an easy fix!

Oh, also- I removed your duplicate post in the Engine forum for this issue. Sounds like a carb problem, and you only need to post in one forum to get an answer.

Post edited by: Johnno, at: 2006/05/31 15:14

the screw is all the way out to where it doesn't touch the throttle parts...

i read another post and i was thinking since my petcock is vacuum actuated could it be leaking/putting too much gas into my #2 carb? and can i just cap off that vacuum line and run it in PRI all the time with the addition of an inline on/off valve in the fuel line?

too much fuel to #2 carb would cause misfire on that cyl I'd be looking for an air leak, or possibly your missing those all important little rubber caps over the pilot jets i had to rebuild my carbs twice seeing as i didn't know what i was doing the first time also put your state at the bottom with you bike info just in case someone is near by

Post edited by: jbw7300, at: 2006/05/31 18:51

Would you suggest pulling these carbs apart myself, or taking them to a shop?

Carburettors scare me. heh.

dive right in there, you may have to do it a couple of times to get it right but with the right info you can get it done (there is alot of good info right here and some real good brains to pick) also shops don't really like to work on older bikes so you best bet is you yourself and a couple of screwdrivers (not the ones with orange juice:P )

Or you can send them to the Carb Guru(I.E WiredGeorge)

Before taking them to a shop, I suggest you check the tension on your THROTTLE CABLE. There must be slack in the cable. Next step would be to turn back the idle adjust knob to make sure it isn't keeping the slides from closing to the point they need to for a normal idle. As far as what it would cost to fix the carbs at a shop, I can't say what other people charge but my charges are clearly stated on my web site. Since you contacted me offline with carb questions, I can only assume you are aware I have a web site. BTW: If you are making adjustments to your carbs and the carbs have OEM jetting, I suggest you install the airbox w/airfilter. In addition, ensure that all vacuum ports are capped that are not being otherwise connected to the emission system or petcock else the idle will race like crazy.

Post edited by: wiredgeorge, at: 2006/06/01 11:05

Well i got about 3 mm of travel out of the barrel adjuster and the idle throttle screw is backed all the way out with a space in between the contact points. I start it with full choke it's running pretty fast but not as insane as yesterday so as it comes up to temp i gradually give it less and less choke. It's idling smooth at about 900 rpm at just under 1/2 choke position. Good throttle response too. Anything less than 1/2 choke and it begins to die. Does this mean i should adjust the idle screw back up just the tiniest bit so it will run properly with no choke?

scirocco17 wrote:

Well i got about 3 mm of travel out of the barrel adjuster and the idle throttle screw is backed all the way out with a space in between the contact points. I start it with full choke it's running pretty fast but not as insane as yesterday so as it comes up to temp i gradually give it less and less choke. It's idling smooth at about 900 rpm at just under 1/2 choke position. Good throttle response too. Anything less than 1/2 choke and it begins to die. Does this mean i should adjust the idle screw back up just the tiniest bit so it will run properly with no choke?

Do you have a manual yet?

I have the kz750 manual which covers shaft models as well. i read through it last night in the fuel section and nothing stood out at me but i'll have another, closer look at it tonight since i am now focusing on a different problem than the original high revs.