TOPIC:

JUST GOT 1978 KZ1000
I TOOK THE CARBS OFF TO CLEAN THEM
AND FOUND THE 2 OF THE 4 SLIDES WHERE SITTING HIGHER
OFF THERE SET'S. THE 2 CARBS WITH THE SLIDES SITTING
HIGHER ARE ON THE SAME SIDE.
IS THIS NORMAL? OR ARE THE SLIDES OUT OF ADJUSTMENT
PLEASE HELP

they should be the same or atleast verry close all the way across. after its running you need to vaccuum synch them.

You can get them sync'd up fairly close by inserting 1/8" drill bits or cut lengths of clothes hanger into the carbs and adjust the slides so they are just touching them. When it is running, using a length of hose, listen to the hiss at each carb and adjust them 'til they sound the same. This is how twin carb Brit bikes have been tuned for years, also the same method is used to tune dual SU carbed MGs, Mini Coopers etc.

Fossil wrote:

You can get them sync'd up fairly close by inserting 1/8" drill bits or cut lengths of clothes hanger into the carbs and adjust the slides so they are just touching them. When it is running, using a length of hose, listen to the hiss at each carb and adjust them 'til they sound the same. This is how twin carb Brit bikes have been tuned for years, also the same method is used to tune dual SU carbed MGs, Mini Coopers etc.

this is a good bit of advice...never heard of this before..i will try this on my bikes as well.

del

Scroll down until you find "simple vac synch tool"

files

Or you can buy a 4 line manometer for about forty bucks. Comes in damn handy. I can see how all 4 carbs are acting and adjust them accordingly. Cheap, handy tool, sure mellows out the idle and vibration.

Buy a manometer if you intend on owning the bike for any length of time. The slides should be all pretty much at the same height (same gap beneath). First thing you need to do is check your compression. If you have gross compression issues, the carbs may already be synchronized; that is, the slides set to allow the same vacuum. If you find you have compression problems, corret those before monkeying around with the carbs. If you find that compression is OK, then use a Kawasaki factory shop manual to guide you through bench sync and then use the manometer. A lot of good advice on this site but few folks describe bench sync as it should be done to achieve the correct results and the factory manual describes how to do it. Since it is described there, I won't bother rehash it. The Clymer description of bench sync isn't very good, imho.

LAST - DON'T TYPE IN ALL CAPS.. it is considered shouting on the Internet and please go to your profile and edit your signature to include your bike year/model and perhaps your location so local folks can possibly help. Thanks! (last paragraph spoken as a cheerful KZRider.com moderator)...

wiredgeorge wrote:

Buy a manometer if you intend on owning the bike for any length of time. The slides should be all pretty much at the same height (same gap beneath). First thing you need to do is check your compression. If you have gross compression issues, the carbs may already be synchronized; that is, the slides set to allow the same vacuum. If you find you have compression problems, corret those before monkeying around with the carbs. If you find that compression is OK, then use a Kawasaki factory shop manual to guide you through bench sync and then use the manometer. A lot of good advice on this site but few folks describe bench sync as it should be done to achieve the correct results and the factory manual describes how to do it. Since it is described there, I won't bother rehash it. The Clymer description of bench sync isn't very good, imho.

Wiredgeorge, I take it you don't agree with my advice. If so, no problem here, point out what's wrong so nobody gets sent in the wrong direction. So far this method has worked for me (flat slide smooth bores - also works for AMALs and SUs), and is quite easy to do. Maybe the advice isn't suitable for all carbs, let us know.

Geeezzz - don't know how I messed up the quote - dropped my reply right in the middle of it!? - tried to fix it but no luck. Sorry.

Post edited by: Fossil, at: 2006/04/29 12:14

Post edited by: Fossil, at: 2006/04/29 12:19

Fossil - It is important to bench sync carbs before using a manometer. The main thing is not just to ensure that the slides are nominally all the same height but to ensure they are the same height with the idle adjustment screw at the correct point. Using drill bits makes this pretty difficult since the slides are opened quite a bit, depending on what size drill bits are used. If the slides are bench synchronized using larger bits, the slides may not be able to be adjusted to where they can actually be synchronized properly within the idle screw adjustment range of the particular carb assembly. Get a Kaw shop manual and read the instructions. All will list the amount of distance between the throttle butterfly and its stop as set by the idle screw. It is usually a bit less than 1/8". Then they specify using about a .5mm wire. There is a REASON they do it this way. The reason is the relationship between the sync adjusters and idle screw which will be hard to maintain using large drill bits unless a person doing this job has a real good feel for the relationship of the parts on the carb. If that person doesn't, then I suspect they will have a real hard time getting the idle set after the bench sync.

I can't comment on the SU or Amal carbs as I don't believe those applications are for motorcycles. I can't comment on sync for car carburetors or how effective the drill bit method is compared to a manometer but I suspect the manometers and bench sync using the method I recommend (and is recommended in the Kaw factory manuals as well) is probably a better idea. If you can get satisfactory results using drill bits, I have no problem with that but I do this for a living and can't waste timing doing stuff in a way that might not give the best results... in other words, it costs me money to do things wrong because it is easier.

del

Howdy All,
I'm working on the same sort of issue with my 750 LTD 4cyl. I've done a rough bench synch already and I have a manometer. Problem...no vaccuum hookups on the intake boots of these LTDs! What gives? Is the tool of any use for these bikes?

Your carburetor assembly has vacuum ports on the engine side on top and toward the center. These are brass nipples. #1 and #4 are generally connected to hoses going to the emissions system OR have vacuum caps. #2 will have a hose connected and going to the petcock and #3 will normally have a vacuum cap. Remove the caps. To sync, connect the hoses from your manometer to these brass nipples and start/warm engine. Once warm and at idle, first make sure the level between 1&2 is equal after loosening the locknut on the sync screw between 1&2 and adjusting this screw. Then loosen the locknut between 3&4 and get 3&4 level. Last, bring the level of 1&2 to be the same as 3&4 using the center locknut/screw. Once you have the levels of all four carbs the same, blip the throttle and readjust as necessary. Don't forget to tighten the locknuts prior to operating or testing the bike.