The International CBX Owners Association

Help needed for jetting my 1979 1000Z please
I was running last year until I have striped down and done the valves new viton stem seals and new rings
Total rebuild with frame blasted and powder coated.
So all back together now,when I was syncing the carbs I couldn't adjust no 3 as nothing was happening the threads had striped
on the screw,so carbs off and split the carbs and put another screw in I have some spares with collection bits over the years from auto jumbles.
I have always ran the engine slightly rich to stop my pipemaster exhaust from blueing,so while the carbs are off ill check on the jetting.

Whats in the carbs now
I am presuming 35 slow jets
2 turns mixture screw
primary 74
secondary 120
with standard slides and needles
I have also ran this setup with Dyna tune stage 3 needles and drilled slides but got a lot of black smoke on acceleration, the bike came with these on

The jets I have to Hand
6/115s 6/96s 6/98s 6/65 6/100s 6/68s
I use E5 fuel which is 5% ethanol in the UK so I am looking for the best setup of jets and needles
Any advice would be helpful

80 primary, 120 secondary, 35 slow, 2 turns mixture screw with stock needles/slides and K&N pods.
Runs well.

The VAST majority will tell you to return to the stock jetting/filter set-up for optimal performance.

I’ve enjoyed several pod-tuned CBXs that generally ran great, were all big-bores too. The gas mileage sucked and they kind-of wanted firm inputs on the throttle, definitely not as dialed as a stock setup, but for a point-and-shoot CBX they are highly entertaining.

Thanks for the reply Steve I am hoping to put it back together today but I can wait to
try and get some 80 jets or do you think the 74s will do or will there be much difference
I don't want to go down the stock route as the bike is not standard

Looking good, friend! Enjoy.

Des i can't speak to the the #74 primary as i have only used the #80.

Always liked the look of the gold boomies on a CBX.

Cheers Steve
I have ordered some 80 jets so they will come next week so Ill let you know how I get on
I have had the wheels on now for maybe 12 years now the rear 18in are easy to get from a vf750f
the front 18in are a lot harder to get I think I got mine off a CB1100f with vf750f discs and callipers

I've used the 120/80 set-up with good success also on '79 carbs with pods. I always wanted to try 78s instead of 80s, think it might be just a wee bit crisper, but have not yet. Keep in mind 'good success' does not equal that of the stock airbox and jetting.

Dave

Cheers Dave the 120 jets are solex jets as I don't think that should make much difference I hope, the nearest and best price jets I can get are keihin 122.5
it would use a bit more fuel i presume

I will only stand by my jet size recommendations if they are genuine Keihin. Others are notorious for being incorrectly sized.

Dave