TOPIC:

I have a 79 KZ650 and for whatever reason I have pilot srews on the bottom of my carbs and air mixture crews on the top. Anyone seen this before? How do I sink these? I just talked to a bike guy and he said it sounds like I have Suzuki carbs on this bike. The bike has been sitting for 7 years and I just bough a 77 motor off of ebay. I'm putting in carb kits and I'm not sure what to do with the pilot scews and the mxture screws. Anyone?

Post edited by: vach, at: 2007/04/11 19:06

I'm no help whatsoever for you, but there were some that had both the pilot and air screws. The 1977 used pilots, the 1978 air screws, but some transition carbs between these models used the carbs with both. I've never seen a set myself, but Kawasaki documents them as used. 1979 should all be air screw type from Kawasaki however.

What model KZ650 are we talking about? The 78 KZ650B2 has both air screws and pilot fuel mixture screws on the stock VM24SS carbs. These are pretty rare. The stock mains are #90 and the stock pilots are #15. I personally think the mains are too small and the bike will never pull through the top end of the rpm range. I would install #102.5 mains. On the screw settings, try 1.5 turns out from lightly seated for the air screws and 2.0 turns out on the pilot fuel mixture screws using the stock pilot jets. The Suzuki carbs also have both air and pilot fuel mixture screws and are jetted very lean from the factory and this is a good setting for them. I don't have much experience with these carbs since there are so few of them but do have a bit more experience with their Suzuki VM26 cousins. One MAJOR difference that will cause tuning differences is that the Suzuki carbs have much smaller holes where the pilot fuel mix screw seats... This makes tuning them much more touchy than yours should be since Kaw specs much larger holes.

Kawasaki Service 4/600-11, 10/21/77

Recently the carburetors of the KZ650 were changed from the pilot screw type to the air screw type. During the transition from one carburetor type to the other, several hundred units were equiped with carburetors that had both air and pilot screws.
Units with transition carbs:
1977 KZ650B Frame # KZ650B024641-026991
1977 KZ650C Frame # KZ650C007751-010000
1978 KZ650B Frame # KZ650B027901-028701
Dealer action:
When you tune a unit with transition carburetors, turn the pilot screws all the way in. This will ensure good idling and smooth running. The air screw setting is the same as the air screw type carburetors.
Pilot screw- Turn all the way in
Air screw- 2 +/- 1/4 turns out.
Direct from Kawasaki.

where do you find that stuff, Ron?

Wow... sounds like the carbs got punched for pilot mix screws without any passageway connecting them with the pilot system so the seated screw just plugs the hole... At least that would be my guess. Thanks Ron... whodathunkit?

Thanks for the info!! It has breather tube on the front top of the cam cover. It does have the pilot and air screws though. I do believe I initialy had the pilot screws all the way in and the air mixture screws at about 2-1/4 out. The bike was originaly dark emerald green so I think it is a b3 and it has an auto-cam chain tensioner so I'm thinking 79. The bike has been sitiing for 8 years and I just bought a 77 motor off of Craigs list for a hundo.. No carbs though. I bought carb kit to rebuild them but I forgot about the pilot and air screws.
I am running 17.5 pilots and 117.5 mains with a Kerker and pods. It ran great when I parked it, I just forgot about the pilots and air screws. I amassuming the are Mikuni's though I don't know because the bike is in Indiana and I'm in Chicago.
This link to a site is pretty informative
jarle.eltelevest.no/Kawasaki/Series/Z/650/z650.htm
This one has some info too.
www.cyclechaos.com/wiki/Kawasaki_KZ650B
This link is good for engine upgrades.
www.oldkawman.com/oknd.html
Some good specs.
jarle.eltelevest.no/Kawasaki/Series/Z/650/z650p2.htm

Post edited by: vach, at: 2007/04/12 16:47

WiredGeorge I think you are right. I remember them being a question and I went to a local bike shop in Indiana and we ended up turning them all the way in. The bike guy had never seen pilots and air screws though. He thought they were from a Suzuki. The bike runs fine that way, so, who knows.

pyxen wrote:

where do you find that stuff, Ron?

Believe it or not, on the parts microfiche for the 1977-79 KZ650B. Besides all the diagrams showing all the parts, down at the bottom there are several service bulletins including various changes Kawasaki made throughout the production, the correct way to remove the cams to do shim adjustments without the need to retime the cams ect. A lot of good info.
Everyone should have a microfiche card for their motorcycle. Of course you need a microfiche reader to read the cards and they are probably getting obsolete. Anyone want the cards get them here, or maybe there's a better way? I'm old school myself.
www.go-fiche.com/

I just found this microfiche macine for 23 bucks, I don't want it maybe someone else does?
cgi.ebay.com/ebaymotors/Microfiche-Machi...Z34237QQcmdZViewItem

KZRon, did you get this off of the Kaw site? Do you have a link?
Thanks man!

RonKZ650 wrote:

Kawasaki Service 4/600-11, 10/21/77

Recently the carburetors of the KZ650 were changed from the pilot screw type to the air screw type. During the transition from one carburetor type to the other, several hundred units were equiped with carburetors that had both air and pilot screws.
Units with transition carbs:
1977 KZ650B Frame # KZ650B024641-026991
1977 KZ650C Frame # KZ650C007751-010000
1978 KZ650B Frame # KZ650B027901-028701
Dealer action:
When you tune a unit with transition carburetors, turn the pilot screws all the way in. This will ensure good idling and smooth running. The air screw setting is the same as the air screw type carburetors.
Pilot screw- Turn all the way in
Air screw- 2 +/- 1/4 turns out.
Direct from Kawasaki.

vach wrote:

KZRon, did you get this off of the Kaw site? Do you have a link?
Thanks man!

RonKZ650 wrote:

Kawasaki Service 4/600-11, 10/21/77

Recently the carburetors of the KZ650 were changed from the pilot screw type to the air screw type. During the transition from one carburetor type to the other, several hundred units were equiped with carburetors that had both air and pilot screws.
Units with transition carbs:
1977 KZ650B Frame # KZ650B024641-026991
1977 KZ650C Frame # KZ650C007751-010000
1978 KZ650B Frame # KZ650B027901-028701
Dealer action:
When you tune a unit with transition carburetors, turn the pilot screws all the way in. This will ensure good idling and smooth running. The air screw setting is the same as the air screw type carburetors.
Pilot screw- Turn all the way in
Air screw- 2 +/- 1/4 turns out.
Direct from Kawasaki.

No, I got it from the microfiche parts card for the 1977-79 KZ650B. It has a few good service tips on it.
There's stuff on there not written on the parts CDs ect. Good to have the CD as well as the fiche if you have a fiche reader.
www.go-fiche.com