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-   -   CIS K-jet, how to make leaner mixture (http://forums.pelicanparts.com/porsche-928-technical-forum/705695-cis-k-jet-how-make-leaner-mixture.html)

iho9 09-15-2012 06:41 AM

CIS K-jet, how to make leaner mixture
 
Hello,

Help needed. Thanks for advice in advance. I think my car runs too rich.

1 .My car is 1983 CIS K-jet 928. Simple question: when I turn the mixture screw clockwise, does the car run on leaner.

2. Has someone experience how much 1/4 turn clockwise approximately has effect on aer-to-fuel ratio?

Regards
Ismo

Danglerb 09-16-2012 07:45 PM

I'm not sure guessing on air fuel ratio is a good idea. Have you pulled your plugs and checked the color?

iho9 09-17-2012 12:02 AM

Hello,

Yes I know it is not definitely good idea just to adjust without knowledge. But in this case it not happening. The smell of exhaust is rich, meaning I you can smell the "too much gasoline" odour in the exhaust. On a manual system it would be like using the choke too long.

Anyways. Roughly how much is 1/4 turn clockwise. Does anybody have even some experience on the subject? Even the direction: is 1/4 turn too much for AFR adjustment?


Backround: The car is 1983 Euro CIS. It runs and starts quite well here in cold Finland.

rjm65 09-17-2012 01:04 AM

Clockwise = richer
Counterclockwise = leaner

Adjust mixture counter-clockwise until it misses (note position of allen wrench) then turn clockwise until it misses (note position again). Now set the mixture between those two points.

iho9 09-17-2012 01:47 AM

Thank you very much!

tychain99 09-17-2012 03:54 AM

no manual adjustments for the K - J? I notice my cars smells like it is running a little rich also..

MPDano 09-17-2012 04:27 AM

A K-Jet will run richer than normal at idle for sure. I run an A/F Wideband Gauge so I know exactly my mixture. It's at 2500-3000 rpms is where it will run at 14.7, it runs around 13.1-5 at idle.

Use rjm65's guidance and he actually got mine started using the same advice.

tychain99 09-17-2012 11:18 AM

not gonna lie, I do not even know the difference between the two.

AirtekHVAC 09-17-2012 11:40 AM

This is from a bike site, but informative, and simple...

Randakk's Cycle Shakk - Honda GL1000 Specialist: GL1000 GL1100 Tech Tip#72

DPW928 09-18-2012 04:57 AM

I would adjust it as rmj65 described as the frequency valve can only make small adjustments to the control pressure based upon the O2 sensor signal.

Dennis

Danglerb 09-18-2012 10:17 AM

Unless some weird thing was done in federalizing a Euro CIS 928 doesn't have a O2 sensor or control system.

DPW928 09-18-2012 10:46 AM

Dan,

1980 and later cars with CIS required the O2 sensor and controls to meet US emissions standards. Some shops may have taken shortcuts and not converted to the KE system. Irregardless, the A/F ratio adjustment is the same on both.


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