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550 breaking down intermitant

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duzatun:
hey lads
   need help with  a problem had for long time when riding every now n then engine seems to start breaking down usually when give her a bit of throttle might happen twice on one ride might not happen for a few rides if i give it a fair bitt of throttle it will cough and splutter but comes out of it seems to be happening more regular.
bike has 4 into one ex
pod filters
jetted up to 105 or 110 if i remember correctly dont seem to have a problem winding her out to high rpm,s normally
I have checked and cleaned out tank
replaced fuel line
tried spare set of carbs
tried spare set of coils
put in new regulator and rectifier
new batt
new condensors and points
 checked earth
looking at replacing wire loom
but this one has got me baffled any ideas

z1100r:

 Errm .. explain a bit more about what is happening. More detail please.
Which of these For example:-
1) your cruising along at 50-60mph and open the throttle and it coughs and splutters and doesn't want to go
2) You've been flat out accelerating no problem but when you slow down its erratic
3) Cruising along just fine for 10 mins then for no reason at all it reverts to missing and rough running.
4) Ticks over fine but as soon as you touch the throttle it falters.
5) Lots of popping and banging in exhaust on overrun.

Which carbs have you got..push in or screw in mainjets...?? Both are drastically affected by removing the airbox but the screw in ones more so. Those airboxes are very resrictive and the carbs need richening up alot - over the entire rev range -  when it is removed.  Changing the main jet only affects thrash mode. I would say you are too lean on needles, primary, and air screw. I couldn't fix mine perfectly without a lambda sensor in the exhaust.

From what you said its an erratic breakdown of something....its fine for ages and then plays up and wont go back to normal without you give it a good thrashing.....just like my missus.

K2-K6:
Have you swapped the plugs to see if it's the same and what colour do they run when it's warmed up on a runout?

duzatun:
well the missing is completely intermittant it might do it warm or when i first get on it sometimes and then doesnt do it at all for a few  rides when its not playing up the motor seems good through all the rev range. seems to be happening more often over the last couple of months. Normally happens when im just cruising then give it a bit of throttle and it acts like its running out of fuel and if i dont give it a good throttle on it won't come out of it for a long time. When i 1st  put the pods on i jetted it up then a had to lift the main needle one notch and adjust the pilots, synced the carbs took a while tinkering to get it running good. ive rebuilt a few sohc,s over the years but never had this prob before have tried new plugs number three has always been a little darker on the plug that could be a number of things nothing major i hope . ive pretty much eliminated fuel delivery problem i think and been inclined to think maybe electrical eg  have tried another set of coils with the same result. so maybe power to one of the coils. electrical can be hard to diagnose with out correct equipment, as you said (just like our women) chuckle
the carbs are screw in main jets

z1100r:

 Well it sounds like you know what you are doing and have tried all the obvious things.

     Dodgy kill switch or ignition switch...???? or something else that may interupt the 12v supply to the ignition system....?????

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