Lean on inner cylinders

I put on some Dyna coils recently and am trying to dial in my carbs on my 79 kz900. The 2 outside cylinders 1 and 4 I get a nice tan color on my plugs. But now it seems the inside cylinders 2 and 3 are very light. Maybe not quite white but close. I keep truning my air screws out little by little and checking them. Is there any reason it would be the 2 inside cylinders doing this and am I heading in the right direction with the air screws? I have them backed out about 2 and 1/2 turns right now and am going to see how that looks. I have checked the float heights and they look good too.

Screwing in enrichens (by reducing air to pilot jet).

Screwing out leans (by increasing air to pilot jet).

Would try 1.5 turns out as initial setting and adjust from there.

EDIT -- Just re-read your post and am confused as to which bike is involved. My reply would be for the KZ900. Am uncertain about the KZ650 which might differ.


Post edited by: Patton, at: 2007/05/22 13:39

Post edited by: Patton, at: 2007/05/22 13:44

If it's stock carb on the KZ650 with pilot screws on the sides and closer to the airbox, would be same as KZ900 (turn in to enrich). If pilot screws are from underneath and closer to the engine, screw out to enrichen.

Sorry not as familiar with the 650 carbs.

Patton, you have me confused... his post said KZ900... air screws... turn them 1 3/8 from lightly seated (per spec) and leave them alone. The air screws are not fussy.

What airbox/pipes are on this KZ900? The factory jetting on the 76 VM26SC carbs is pretty rich.

stock airbox with K&N filter stock jetting

wiredgeorge wrote:

Patton, you have me confused... his post said KZ900... air screws... turn them 1 3/8 from lightly seated (per spec) and leave them alone. The air screws are not fussy.

What airbox/pipes are on this KZ900? The factory jetting on the 76 VM26SC carbs is pretty rich.

KZ900 is also what I first thought upon reading the initial post which says 79KZ900. After replying, then noticed signature bikes listed both 1979KZ650 and 1976KZ900 and concluded 79KZ900 was a misnomer. Go by year or by model ? So edited my reply.

And the kawasaki.com site seems to show '79KZ650's with either of two different carbs, one with pilot air screws on side and another version with pilot mixture screws from bottom (unless I've mis-read the parts diagram). :ohmy:

Concur with 1 3/8 initial setting on KZ900, but agree it's not fussy (1.5 is just so easy to find :lol: ).

Believe bkitchen is way too lean at 2.5 turns out if dealing with pilot air screw on KZ900. Whole different ball game if a 650 with pilot mixture screws (of which I know zilch). :huh:

Remain uncertain which bike, but know it's NOT a 79KZ900. :woohoo:

With WG on board, he's in the very best hands.

Since I have two KZ900A4s (76 models) I just read the thread that way and didn't notice the 79 stuff you caught... Anyway, the stock VM26SC for 76 is the richest mixture of any of the 26s. #115 mains, 5DL31-3 jet needle (same jet needle and clip set as a VM29), 0-6 needle jet (same size as a VM29 smoothie) and #17.5 pilot make the 76 VM26 version very adaptable to use of aftermarket pipes and a K&N... really, you should be able to run stock jetting without running lean or seeing white on your plugs. I would look for poor sealing on the carb holders or low fuel levels in the bowls or obstruction in the fuel line (including any filter, etc). I have used these carbs extensively with a K&N and 4 into 1 and also a 4 into 2 and they are not lean even with stock jetting. Be sure to check your jetting because it is always possible you don't have 76 KZ900 VM26 carbs... but these carbs are the only 26s with air screws.