RiderForums.com - Kawasaki Motorcycle Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter #1
Hi All

I have a UK spec 2004 ZR-7 with a dynojet and K&N filter fitter. All carbs are set to the same needle height but one cylinder is running rich. The bike also hesitates at low RPM.

There are loads of old threads on this forum that look like they originally had pictures but I guess those threads are so old now, the photos are gone.

Can someone point me to the location of the mixture screws on my UK spec'd bike. I assume I need to wind it out (anti-clockwise) to weaken the mixture? The other 3 cylinders seem to be running around the same colour on the spark plugs...
 

·
Registered
Joined
·
5,160 Posts
The arrows show where they are. They may be covered by caps if they've never been adjusted (as per the 2nd pic)
I'll find the old write up shortly and post it.


122233


122234
 

·
Registered
Joined
·
22 Posts
Discussion Starter #3
That's perfect, thanks.

I only need to tweak the mixture on one of the outside carbs. I guess 1/4 of a turn at a time? Do I need to rebalance the carbs if im meddling with the mixture?
 

·
Registered
Joined
·
5,160 Posts
The common best spot is about 2 1/2 turns out. You gently turn them clockwise until they stop, then turn them back out.

If you end up completely removing them there's an order for the parts to go back in. It goes rubber o ring, washer, spring, needle. It's not uncommon for the O ring to stay inside, or go bad as mine did and i had to replace them.

Here's the bad ones (in bits on the top)

122235


And here's the new ones.

122236


I likely could have just found new o-rings and made sure I got all the old bits out of the carbs, but I put in new everything just to be sure.
 

·
Registered
Joined
·
5,160 Posts
1/4 at a time is a good idea.
 

·
Registered
Joined
·
5,160 Posts
I've never balanced my carbs and I've had them apart and cleaned at least 4 times. YMMV.
 

·
Registered
Joined
·
5,160 Posts
122237
 

·
Registered
Joined
·
22 Posts
Discussion Starter #8
Thanks for the info. I assume screwing the jets clockwise in to the carb weakens the mixture(gives more air) because the jets are on the engine side of the carb.
 

·
Registered
Joined
·
5,160 Posts
I forget if they adjust the air or the fuel. Normally they adjust air if the screws are before the carb, and fuel if they are after the carb - but I can't recall for sure. The are called pilot air screw, so I'm going with air.
 

·
Registered
Joined
·
244 Posts
Usually if the adjuster is at the bottom it will adjust the idle fuel qty. If the adjuster is on the top then its adjusting the idle Air.

Plumpton, I don't really think its a problem with the idle adjustment as they rarely go out of adjustment.. there could be some dirt so remove the screw and shoot some carb cleaner up into the hole (having removed the o-ring, washers spring) and re-installing them to the same position.

Before removing them, screw them in and count how many turns to get the screw to the fully screwed in position. When installing screw them fully in and count similar number of turns out.

Running rich is also a symptom of an intake leak..check that the rubbers are tight both at the head as well as at the cars. Spraying carb cleaners around the inlet and listening for changes in the RPM help identify leaky rubbers.. be careful as carb cleaners are very flammable.

You also mention that the bike hesitates... this used to be a problem when the bikes were new I believe and the solution was to unscrew all the idle jets out to richen the off-idle middle. Leaning off the offending piston will not solve your issues.

Finally I realise this thread is about a month old ... sorry about that as I don't stop here regularly!

Anilv
 
1 - 10 of 10 Posts
Top