OMR: '76 KZ900 Restoration/Modification

re-synch after a pilot or main jet adjustment

The Dyno tech also mentioned they where a little off whcih I as well found odd where I had them dialed in within 2cm of each other pre Dyno...

Sure enough, whe I re-measured, was slightly out between them... I guess after some run time and letting things settle in/vibrations effecting vacuum/itakes what ever, they shifted a little.

Boy, I waish I had a home Dyno for these carb tweaks.... :laugh:

Presently having to drop a size (smaller for leaner) on the slow jets @ idle to 1/4 throttle... Backed out 2.5 turns so riding on the cusp (actually over I believe) to get through emissions here in AZ.

The idle standard CO% is 5.5 and I came in at 8.1 after ramping up to 2500 then back down to idle....

Stock are 60's, Will order the next size smaller at 58's... Re-adjust the pilots 1.5 to 2 turns out/ until it starts popping out the pipe (too lean) then back her out slightly, take her for a spin then re-test for emissions....

OMR

I thought with all the tuning u did with the new toys they would have been perfect?
I’m not trying to put you down at all. Just wondering what’s up.

Plummen, that’s pretty vague. Come on bud, cough something up hear. A hair bal or a bone or something. lol:P
What I meant was, after u spend time to get the slides synched right, why would the side levels change , if u make a jet change? Or maybe I should say , why would the cyl breath dif?
My understanding about synching is that u are trying to match each cyl to breath the same. Since each port will have a slightly dif vac signal, due to all the variances in the ports, valves , seats…..

its a new combination hes running,its just gonna take a little headscratching to get it right on the nuts of where it needs to be.

:laugh: where do u get this stuff. lol
I must say, u are very entertaining. Thanks for that.:lol:

gonna take a little headscratching to get it right on the nuts of where it needs to be.

Yup.... See here in AZ, unfortunately I have to get it emissioned to register. The motor runs strong, pulls extremely well but still a little on the rich side fr the emissions.

As you all know, with any carb configuration, new or old/re-builds, this is a painful process that is required to get her dialed in. There's temperatures, humiduty, elevations, vacuum, manifold leaks etc.... that all play into the "Dialed In" equasion....

Once there... golden!

NOTE: Copied from my carb section posting & reply... Just an update to my project....

Well, I'm good to go.... passed with flying colors!

There's actually a funny story to it....

As mentioned, drop to number 3 on the needle jet clip and I installed the 58 slow jets this afternoon.

In using the color tune, due to the 58's, goes from yellow .5 turn out to bunson blue at 1.5 turns out.... So 1 to 1.25 turns out (half way between the two is about correct ...

With this in mind, I tweaked her out as far as possible, popping out the pipe so backed her out about 1/8th turn....

Drive to emissions, ran like shit lol, where they have you shut her down then start her up for idle test.
SOB wouldn't start so I had my screw driver and oh no, you can't do that... Ok, so went for the choke, oh no you can't do that... WTF you sonsabitch...

Ok, if I roll it out of the bay, make my tweaks and come back... She replies, No problem! ROFLMFAO.... So for emissions, 2.75 turns out will do it...

Out the bay I go.... Tweak her back about 1/4 turn, adjust the idle and back into the bay I go... Old girl flew through with no problems...

As mentioned, CO% Standard is 5.5%.... Measured in at 2.80% SWEET!!!!

Once out the bay, tweaked her back to 1.25 turns out and took her for a drive... Twist the throttle and she screams nicely with no back fire... I'll keep my eye on the plugs.....

Anyhoot.... Thanks again all...

For future reference....

Kehins CR Specials:

Main Jet: 115
Slow Jet: 58
Needle Jet position # 3:
Pilot adjust 2.75 turns out for emissions.....

OMR

AZ Emission jetting change to PASS!

Kehins 29mm CR Specials:

Main Jet: 115
Slow Jet: 58
Needle Jet position # 3:
Pilot adjust 2.75 turns out for emissions.....
For ideal operations Pilot adjust ~ 1.25 turns out...

Found a new Color Tune chart...

Step 2: Now this made a difference where I would previously run on the rich side (yellow)...

Slight adjust of the slow jet screw (pilots) where it stays blue between 1000-3000 in a slow twist of the throttle!

She runs strong!

can you keep up with traffic now? :laugh:

One word- WOW!!! You do amazing work!! Kudo's for getting her on the road!!

Ben

Well all.... For the most part she's complete! :woohoo:
It's been one hell of an 18 month period and I thank all of you who helped me out, especially Plummen and Larry C....

Oh yeah, so he doesn't bitch at me again Steve Kaw-SUK-man.... Love ya brother and I do mean this... Thanks!

The next 3 image sets are 360* image shots around the bike....

OMR


1976 KZ900-A4 Street fighter modification with ZX636 front end and ZX6-RR rear J link mono-shock.
All fabrication, welding, paint accomplished by myself.

NOTE: Cylinder bore & Head accomplished 3rd party...

Motor upgraded to 1015cc. Wiseco Pistons and rings.
Cams: WebCam .365 lift, 283 duration, 246 duration @ .050
Head: Valve 3 way grind with Port & Polish via Larry Cavanaugh @ Cavanaugh Racing Heads. (New SS Valves, Guides & Seals).
Carbs: Keihin, 29mm CR specials, Dynoman Filter PODs
Kerker 4 to 1 exhaust with 1.5" competition baffle.
Dyna S Electronic Ignition and Coils (GREEN 3 Ohm).
Liske Timing components & Tsubaki Heavy Duy Timing Chain
Rar Sets: Used Kawasaki ZX-7
Spiegler Black Chrome Braided Stainless Steel Brake Lines.
Front Rotors: EBC
Digital Speedo/Tach combo: Acewell 2802 Series

Image Set 2....