bike running rich..z1000a1

[gordon62]

Hi all,
have discovered my bike is running rich , as plugs are soot black.. I have remove the carbs for inspection, and found 1 pilot jet broken top, and the mains are 112.5, standard accordint to the book, should be 107.5, so I"m wondering if the main jets are too high, making it run rich, would up by 5 make much different? she runs on standard airbox and filter..I have yet to check the needle heights, I hoping that the jet size will be the main cause of this, also where is the best place to get these parts,
cheers,
Andy

[chrisu]

I'd be tempted to go back to std if you've got std airbox and std or baffled pipes. Race baffle pipes etc then maybe not.

I got my carb rebuild kits from NRP - includes all jets etc. Just tell them what bike its for.

Have you also checked voltage at the coils ?

[gordon62]

Hi oh yeah and a vance and hined exhaust..

[Z.O.A]

Hi Andy, try www.motocarb.co.uk as well, he seems to have a lot of sizes in stock and only about £2.40 per main jet. Make sure you order the correct type tho,as there are are 3 different types of mikuni main jets.

Another area well worth looking at as well tho is your fuel/air mix on the carbs, I found a gunson colourtune a great gadget for getting this right.

Also, while you have the tank off and because it's easy to do, check the voltage going to your coils is correct with a multimetre, if they're not getting the correct 12v then they are not sparking right and your plugs will foul up badly the whole time.
Hope this helps, good luck

[Phil50]

Hi
I have Z1000 a1 Carbs fitted to my Kz900 I had a terrible ongoing problem with rich running and spit back at 3000 rpm
solution was actually very simple. I bought a repair carb kit from NRP
0161 832 8646
The Kit number is KK-0157NR

The problem was, I fitted the entire kit ok but put in my KZ900 main jets size 115 per the book. I should have put in the ones from the kit 107.5 Also the mixture volume screw underneath the bottom of the carb should only be out 1 and 1/4 turns. This plus a brand new battery (essential if yours is more than 2 years old) Now it runs like a rocket. No richness, no balancing errors and no spitting or back fire at 3000rpm.
I did get the carbs cleanen ultrasinically but this I think was less of a problem.

As usual it is a small amount of little problems.
Good luck.
Phil

[gordon62]

Hi,
I might go for a kit, can you tell me how much they are amd what is in the kit, I going to check my carb over this morning,
Andy

[Phil50]

Kit is about 75£ for 4 but its well worth it.
You get EVERYTHING you need
Chamber Gasket (rubberised not paper!!!)
Needle valve
Jet Needle
E Clip
Air Screw
Air Spring
Main jet 107.5 (very important)
Pilot Jet 17.5
O rings
Needle Jet
Top cover Gasket

The only aggro is removing the Jet Needle from the base of the carb via the top of course you have to remove the throttle slides.
I used a jewels nut driver the same diameter as the brass jet and gently tapped it out. It pushes back in to the flange easily and put the circlip on the centre position. Use a 7mm diameter piece of wire from the cylinder head side of the carb to set the slide height for start position before attaching gauges. It is usally 90% correct then. Oh and also measure the voltage at the coils input before ignition is on and if it drope more than 1 volt get a new battery. I had no end of trouble and after a new battery was added and a new combined regulator/rectifier(electrex.co.uk £ 58.00 inc vat p and p) Today it went like a new bike. Except when the damn fuek pipe to 1 and 2 carb got the usual kink in it and power was lost. Sorted in two mins though. Lots of fun isn't it?
Phil