Still running lumpy after a few parts changes

well the old girl is definitely running better after the parts changes below but she still misfires a little and pops and bangs when you rev and drop throttle, especially when engine colder.
Also I can feel it drop power slightly then pick back up also when cruising at mid speeds like around 60-70 MPH. It's like one of the cylinder isn't firing properly all the time.
Definitely gets better as get hotter..

Work done and parts replaced to solve the problem
Removed Carbs and cleaned up.
Replaced plugs(B8ES) Leads and caps (although I'm not overly happy with the quality of these and will change them again)
Replaced all carb rubbers (in and out)
also changed oil and air filters (wow oil was dirty !!)

Will carb balancing make a difference? i was informed it's not worth doing that until it's running ok..
Any more ideas? (Coils perhaps?)

No mention of Valve clearance/adjustments or ignition timing to specs...
Must get this accomplished!

How'd the engine run pre-work regarding the popping...?

Battery/charging system components to spec...?

Spark plug conditions (bright white, detonation specks, carbon build up etc...)

Cam timing (tooth count and lobes to deck @ 1/4 TDC) to spec...?

Carbs cleaned...
Outer bodies only or had you taken them apart for the slides, jets, needles etc...?

Run her @ 65mph steady, then let go of the throttle. Let it snap back to idle position...
She pop and backfire.... If so, running a tad lean on needle/clip if have one/main jet.

Off a rolling start, twist the throttle... She hesitate, miss pop etc... same as above, lean mixture.

Confirm you don't have a vacuum leak in the manifolds...

And yes, Carb sync must be accomplished as well...
May have to accomplish several times through the process to get dialed in.

OMR

Have you run a compression test? As OMR suggested, do the valve adjustment. As dirty as you found the oil, it more than likely has not had the valves set to the proper clearance.
But saying it gets better when hotter, sounds like it could be lean on fuel on one or more carbs. Have you checked/ set the fuel level in the carbs with a clear piece of tubing as a sight gauge? You want to make sure that things are even, compression, spark, fuel etc before doing a running sync. So the dynamic/ running sync should be done, but you should set the carbs up as even as possible on the bench first. Get the compression even, make sure the spark is correct and the timing, No vacuum leaks, carbs really clean Inside all passages/ jets.

I've just found the air screws (sorry no manual) and they were screwed out one turn.!!
After screwing them out 2 turns the whole bike has transformed..
I knew it would be fast but it's like a different bike !
One of the pots is still popping a little but nothing like it was..

KZ1000inaus wrote: I've just found the air screws (sorry no manual) and they were screwed out one turn.!!
After screwing them out 2 turns the whole bike has transformed..
I knew it would be fast but it's like a different bike !
One of the pots is still popping a little but nothing like it was..

Slightly enrichening the pilot circuits sometimes reduces exhaust popping on deceleration.

Air screw is side-located toward rear of carb. In for richer. Out for leaner.




On the other hand, a mixture screw is bottom-located on engine side of carb. In for leaner. Out for richer.



Good Fortune!

On the other hand, a mixture screw is bottom-located on engine side of carb. In for leaner. Out for richer.



Good Fortune! [/quote]

Ahh finally i see a pic of what mines like with bottom external screw.
Excellent thanks.
i turned mine out two turns and it seems to be running so much better.
What's too much? as i see a manual cutting say 1 1/8 but you say don't be a slave to it.
I'll need to fiddle around with each carb but i will get there.