KZ1000 LTD Jetting help.

Hey guys, I'm new to the forum and new to the big block Kawasaki scene as well. I've done a bunch of stuff with smaller KZs, Hondas, Yams, and Suzukis, but never anything based off from the Z1 motor.

I just picked up a 1980 KZ1000 LTD that's had quite a bit of engine work done to it by previous owners. The engine work list includes: A Wiesco 1054cc 10:1 big bore kit, .380 high lift cams (lift numbers from installing shop paperwork, duration and brand unknown to me at this point), Dyna electronic ignition and green coils, Kerker exhaust, and is used to have 29mm Mikuni smoothbores but were recently replaced with the 26mm(??? I haven't put the calipers on them to measure them. I believe I've read that these bikes were supposed to come with 26mm Mikunis, but on here and on Ebay I saw that they were 28mms? Anybody know what should be stock?) stock carbs with individual Uni-air pod filters. The smoothbores were replaced by the previous owner's shop as he said they were worn out beyond repair... Curiously enough, the shop did not return them to the previous owner after installing the new carbs.(can you say ripped off?) Anyway... that doesn't matter for my question so much.

When I picked up the bike it had a leaking needle valve so I pulled the rack off and replaced all 4 and the fuel bowl gaskets too. The main jets were 117.5s (vs. stock 102 mains) with stock pilot jets (at least the same as what were supplied in the K&L rebuild kits). I'm wondering if these were simply pulled from the 29mm carbs that were scrapped??

On my first ride on it, I wasn't blown away by it. I expected the motor to be a bit of a monster with the stats on paper, but it felt pretty darn flat on top making me think it's a bit rich. If the mains were pulled from the 29mm carbs, it should be rich as a bigger carb, all else equal, should need a larger main to produce the same mixture. At least that's my thinking...

Anybody have a similar set up? Jetting suggestions?
Any luck with running individual air filters or should I be finding an airbox for it?

Thanks in advance for any suggestions.

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Thanks guys/gals.

Chris

I do actually have the 26mm carbs on it.

I tried a set of 108 mains that I had kicking around and it was too lean. I ordered up a set of 112.5s and put those in the other day and it seems better. Actually, the bike pulls really well up though 5k or so and then it starts to fall a bit flat. Fuel screws are set at 1.5 turns with stock pilots.

I've got a set of cheap-o small uni-filters on the bike and I'm wondering if I'm seeing a rich condition at high rpm now because the filters are too restrictive? Seems a bit weird to me since they should have more total filter area than a stock replacement K&N filter... I ordered a set of the APE filters though today to try.

On another note, has anybody tried boring a set of 26mm carbs? It looks like there is plenty of indentaton on the slides to get 1-2mm of extra bore diameter. Maybe they are the same castings/slides as the 28mm miks on the other bikes? Just looking for some input.
Thanks.

if it's not pulling well in the mid-range 4-6000 try raising up your needles a bit to richen it up in the middle.and the 26 mm carbs sound like there are stock sized.too bad you don't have the 29's they are great carbs and by the way i have never seen a set of them worn out.

If not already done, could check for possible fuel starvation resulting from clogged vent in tank cap by test running with cap ajar (not snapped completely down).

And also assure petcock pickup tube screen is clear and unclogged, and if manual petcock that filter screen over sediment cup is clean.

And that fresh inline fuel filters are fitted.

And use clear plastic tube test to assure correct floatbowl fuel level. Being 2-4mm below bottom of carb body, same as 2-4mm below floatbowl gasket.

The best test imo for correct main jet sizing is plug reading after high speed throttle chop (simultaneously killing ignition, disengaging/squeezing clutch, and coast/brake to stop). Carry along a short length of tubing that fits snugly over spark plugs to aid removal of hot plugs without burning fingers.

Should be able to jet the 26's for adequate performance throughout the throttle range on this bike.

Good Luck!

Would not fool with "boring out" the 26's.

Good Luck!

if it's not pulling well in the mid-range 4-6000 try raising up your needles a bit to richen it up in the middle

^+1 or go with a different taper on the needle for your riding style and check the synch

The best test imo for correct main jet sizing is plug reading after high speed throttle chop (simultaneously killing ignition, disengaging/squeezing clutch, and coast/brake to stop).

^+1 as well.