Understanding the basics, with reference to the zxr400

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jimsym
Posts: 93
Joined: Sun Feb 03, 2013 11:39 pm
My Bike: ZXR 400 L9
Location: Hertfordshire

Understanding the basics, with reference to the zxr400

Post by jimsym »

Hi guys,

My L9 is running okay, but I think there is room for improvement - basically its cold idle is very lumpy, and sits at about 600 rpm, whilst when upto temp idles about 1600rpm - a tad too high if im honest.
Secondly, any amount of choke will stall the bike. I have a feeling it might be setup to run too rich.

Anyway, before I take the carbs out and have a look, I want to understand the zxr400s idle / pilot circuitry.

Am i right in thinking the flow on the pilot jet is constant / non adjustable, and fueling at idle is adjusted by varying the airflow with the pilot air screw?

Only, whilst doing research, it seems that sometimes bikes have an adjustable pilot air screw, and some have an adjustable pilot fuel screw, slightly confused right now!
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CaNsA
zxr400 oc member
zxr400 oc member
Posts: 1741
Joined: Sat Nov 29, 2008 4:02 pm
My Bike: ZX6R F1
Location: Liverpool

Re: Understanding the basics, with reference to the zxr400

Post by CaNsA »

basically its cold idle is very lumpy, and sits at about 600 rpm, whilst when upto temp idles about 1600rpm - a tad too high if im honest.
mine is about 1500rpm when warm, dont worry about it.

Secondly, any amount of choke will stall the bike. I have a feeling it might be setup to run too rich.
that or the pilot jets are the wrong size

Anyway, before I take the carbs out and have a look, I want to understand the zxr400s idle / pilot circuitry.
Am i right in thinking the flow on the pilot jet is constant / non adjustable, and fueling at idle is adjusted by varying the airflow with the pilot air screw?
Only, whilst doing research, it seems that sometimes bikes have an adjustable pilot air screw, and some have an adjustable pilot fuel screw, slightly confused right now!
During your research did you come across.....
http://www.zxrworld.co.uk/zxr400/lmodel.html
http://www.zxrworld.co.uk/zxr400/lmicro.html


You will find all your answers there.
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