TOPIC:

i like the graph Mikuni uses to explain it .

My assumption was that with the increased air mass flow rate the pods and straight pipes give you should increase the signal strength at low RPMs? I may be getting all wrapped around the axel here though.

ok at the moment replacing the carbs really isnt in the budget at the moment but i did put some small baffles in the pipes today and it
smoothed out a little bit. one cylinder seams to be running fine but the other has a pop to it like a small backfire is this something that the mixture screw would take care of?

bone head wrote: . . . one cylinder seams to be running fine but the other has a pop to it like a small backfire is this something that the mixture screw would take care of?

Backfire through the carb may result from a too tight intake valve clearance, or failure for whatever reason of the intake valve to fully seal when supposedly closed. And where backfire through the carb results from failure of an intake valve to fully seal when supposedly closed, changing the air/fuel mixture would imo not be expected to reduce the backfire.

If not already done, it's likely time to check the valve clearances, and adjust the clearances to spec where needed.

Good Fortune!

i have already adjusted valve clearance all 4 valves are with in spec at .18mm. just double checked and they are still at that. but i did just find that pulsing coil dose have a crack in it but i dont know if that would be the source of problem. guy at locale shop told me to rejet bigger yet cause it was still lean so i tried that and got worse and my plugs where black before that so that would say im to rich correct?

to be honest the fact that you can't get over 4K RPM says there is something worse than just a little lean. what kind of filter are you using? make sure that the filter isn't blocking the vacume to the diagram. it sounds like your diaphragms are not lifting fully . have you tested how fast the diagrams fall when the vacume port to the diaphragms are blocked? either that or your jets are still plugged up . unfortunately these bikes are quite expensive to get back into running shape most the time.

bone head wrote: i have already adjusted valve clearance all 4 valves are with in spec at .18mm. just double checked and they are still at that. but i did just find that pulsing coil dose have a crack in it but i dont know if that would be the source of problem. guy at locale shop told me to rejet bigger yet cause it was still lean so i tried that and got worse and my plugs where black before that so that would say im to rich correct?

plugs where black before that so that would say im to rich correct? -- Not necessarily, because black plugs may also result from weak spark (for whatever reason) and/or insufficient compression (for whatever reason).

Good Fortune!

i dont have a compression test but it feels good when rolling over by hand. i guess im at a stand still for now. i ordered the only pulsing coil i could find so ill wait for that to get in and see what happens. do you thing timing chain tension mabye? its the only adjustment i havnt made but its not making noise so i wasnt worried about it

alright i got the bike running alot better. idles good, runs good at wide open throttle, and good in mid range BUT if i just touch the throttle slightly it bogs down. but when i get to 1/4 throttle it flatens out. iv got #92 primary and 78 for pilot jets and needle is at stock. any suggestions. do you think it would be the pilot even though it idles perfect?

The 1981 KZ440 would have CV carbs, and you state "its running straight pipes with pod filters." I suspect trying to tune it so it runs well throughout the throttle / rpm range is going you drive you crazy. Ed

A plug chop at that speed should tell you.
Steve

bone head wrote: smoothed out a little bit. one cylinder seams to be running fine but the other has a pop to it like a small backfire is this something that the mixture screw would take care of?

I had that on #1 carb so I backed out the pilot screw for that cylinder, fixed it

i am no longer running the straight pipes any more i have extended the pipes to the rear axle and put in 4 inch baffles. i am still running the pod filters. iv got it so close but its just not quite right yet. what is a plug chop?