Carb help

[Kawasaki_rick]

!st off i have a 81 ltd1000 (kz1000). I got it all original. Guy i got it from said carbs just need cleaning. So i took the carbs off, they were clean as a pin. Started looking around And found coil wire off and two spark plug wires switched. I bought a pipe off ebay(kerker street pipe with baffle). Then i went to pod filters. I started rejetting. Stock jetting was 37.5 for pilot 122.5 main. I switched out main for a 130. Bike run well idleing and wide open. But half throttle response spit sputtered. I looked at the new plugs white as hell. Gotta get it fatter i thought. I upped the pilots to 40. and then the mains 140. Still sucked part throttle. So i thought needle position. Put 1 washer inder needle. Same thing no change. Im stumped. These are stock diaphram type carbs. Any1 got any ideas?

[Bub]

Had the same issue with mine, finally go tired of messing with it and got a set of Mikuni flat slides. Not saying you cant get it, I wasnt patient enough

[Kawasaki_rick]

Im not gonna give up. Im thinking about drilling the holes in the slides so they will come up easier. But i dont know what size yet. Waiting to hear opinions.

[kawasakijockey]

Could be ignition advancer mechanism is stuck. Mine did and I went through the carbs twice before finding the issue.

[Kawasaki_rick]

Checked that. Its working=free.

[fj1289]

I'd go back to the 130 mains. Try 2 or even 3 washers under the needles before drilling the slides. I'd look at a jet kit for different profile and adjustable needles before drilling the slides.

Also, are you sure all the passages are clear? Just because the insides look clean on the surface, doesn't mean all the internal passages are clean.

[HEAVYHITR]

THE BIKE HAS TO BE LEAN AS COULD BE !! WE USED TO TAKE THE AIRBOXES OFF THE OLD GS1100'S AND GO TO LIKE 160 MJ WITH FILTERS AND 180 HJ WITHOUT .

NOW IF YOU FIND A WAY RICHER NEEDLE THEN YOU PROB WON'T HAVE TO GO AS HIGH .

TAKE THE INTAKE MANIFOLDS OFF AND MAKE SURE THEY'RE NOT CRACKED AND RESEAL THEM .THATS #1 COMMON PROBLEM BECAUSE THEY AIRLEAK AND WON'T PULL THE FUEL RIGHT SO BACKFIRE FROM LEAN .

IF ALL DOESN'T WORK TRY SHIMMING NEEDLES ALOT

[Kawasaki_rick]

Update, drilled the slides, as recommended dynojet. shouldnt of done that. runs worse. I took a set of carbs off my other ltd. same exact bike-same yr. runs same way. pretty baffled. i got another rack of carbs here. gonna start fresh. Oh i also took the advancer unit out of my 1st bike. To eliminate that being the problem. same thing. I wont give up even if it kills me.

[moondogspot]

ru running air filters?
if so go to radioshack get them little tiny washers they sellbuy about 20 cause your gonna drop one or two.
pull the tops off the carbs on the bike with out pulling them makes this go alot faster
put 2 washers under the needles on each slide
start there if u got a quick run tank say off a lawn mower so u dont put all this stuff on and off 10 times it will also move faster
plug the holes back up in your slides an since u listened to dyna jet they also have plastic light weight plugs for when this dosent work and you have already drilled the slide
if it smooths out try 3 and so on
if your not running air filters you will have to do this and way up your main jet size to work with all the air
try some tape on the back of the inlets of the carbs to reduce the amount of air rushing in this will richen it up if it clears up more jet if it dosent needs more air
air filters singles sprayed with kn oil on cv carbs will slow down the air also till the oil is gone
but may tell u if u need to richen it up some.

moondogspot

[Kawasaki_rick]

Im really thinking its not the carbs. Does anything else affect midrange. My other bike runs great, same set-up. CDi?

[moondogspot]

Stupid question on my end not yours.
Have you done a compression leakdown.
Also when was the last time you ran threw the valves.
Rember these motors are 8 valves so just a little outta tune and they run like crapola.

Probably not a problem but while you got the valve cover off look at the cam lobes make shure that low oil pressure hasnt tryd to wipe a lobe off one of the cams.I know you think its stock but its old and sometimes somone before you might have put a soft cam in and that can make it run crappy in the midrange but idle ok and pull good when all 4 cylinders are masking the one dead one.

One of my buddies been riding an old kz for 3 years on three cylinders.Finely quit working on it hiself and let me work on it.
I put gsx-f katana 600 carbs on it , dyna s ignition and green coils cause one plug wire was not sparking the plug at all, adjusted the valves,and put an old kz andrews cam on the intake cause his was shot ,one lob almost round.Pulled the oil pan it was full of all kinds of stuff.Put in new clutchs and springs.He was use to throwing the clutch away and spinning the tire.Well he threw it away after i worked on it it spun the rear tire about 40 feet hooked hard cause it use to blow threw the clutchs stood strait up in the air.Well he got it back down but he dont ride like that anymore.

If you can go dyna S it will work very well on a street,and you can forget the factory cdi box.

Moondogspot

[HEAVYHITR]

Im really thinking its not the carbs. Does anything else affect midrange. My other bike runs great, same set-up. CDi?

DID YOU RESEAL THE INTAKE MANIFOLDS ? MAKES A BIG DIFERANCE

[Kawasaki_rick]

Might of found it. When i got the bike the guy said he had just got a elec box for it, Cost him $450. I was like ok whatever. I found it laying back b-hind the battery. i disconnected it. plugged in original, it was still on bike. Bike started right up. Snowed here today. Cant wait to see if its fixed. Thanks for suggestions.