misfiring a4

hiroz · #1 PostAuthor: **hiroz** » Wed Feb 13, 2008 7:54 pm

hi there,

after finishing the restoration of my z900a4 it has a flat spot problem,
first time up the road between 2000 and 3500 revs it splutters and misfires
like its dropping onto two or three cylinders but when it reaches 4000 revs it pulls like hell.

can anyone throw some light on the problem.

#2 PostAuthor: **chrisu** » Wed Feb 13, 2008 8:00 pm

sounds like pilot jets.....................

Pigford · #3 PostAuthor: **Pigford** » Wed Feb 13, 2008 8:03 pm

What throttle openings does it happen at:

eg, part open............... or.. half open......... or... fully open :?:

Have you checked rubbers for cracks/perishing :?:

What filter/pipe set up :?:

hiroz · #4 PostAuthor: **hiroz** » Wed Feb 13, 2008 8:17 pm

it seems to be on part opening to half throttle opening,
inlet and airbox rubbers are all new, and i have the standard airbox and brand new 4x4 pipes fitted.

#5 PostAuthor: **chrisu** » Wed Feb 13, 2008 8:23 pm

clogged pilot jets

Pigford · #6 PostAuthor: **Pigford** » Wed Feb 13, 2008 8:47 pm

Check fuel level (float heights) and may require needles lifting a notch (clip down #1) as Zeds often run lean on in intial take off :evil:

This assumes ignition system is A1......

scott · #7 PostAuthor: **scott** » Thu Feb 14, 2008 8:38 am

Hi guys,
i had exactly the same symptons on my zx7r last week. I had replaced the plugs.....turned out to be a plug breaking down....at low revs it ran on three...as soon as i opened the throttle more, it pulled through it. I don't know whether it has any bearing on this problem...but it could be a plug breaking down.

Scott

pablo · #8 PostAuthor: **pablo** » Thu Feb 14, 2008 10:15 am

If you've just put it all back together I'd say it could be any one of a number of things!

I'd check ignition - standard points? - did you fit new condensers? - coils okay?

Also, obviously, carbs. Did you clean them all out?

Cheers, P.

debben1 · #9 PostAuthor: **debben1** » Fri Feb 15, 2008 12:22 am

Check the auto advance unit too,

hiroz · #10 PostAuthor: **hiroz** » Fri Feb 15, 2008 5:38 pm

the bike has a new dyna s ignition fitted, new coils from z power although i have a brand new set of dyna coils to fit if necessary has anyone had any experience of running with dyna coils fitted are they well suited or not . so engine has been timed and auto advance is working perfectly.
must be carbs i hope ! :??

Pigford · #11 PostAuthor: **Pigford** » Fri Feb 15, 2008 6:46 pm

Dyna coils & Dyna S will be 10 x better than original :wink:

As long as its all fitted OK :shock:

Iain marshall · #12 PostAuthor: **Iain marshall** » Fri Feb 15, 2008 6:52 pm

Have a look at the carbs and keep us posted,are you going to the Ingilston show this year?catch up with you there(thats got you thinking)

pablo · #13 PostAuthor: **pablo** » Sat Feb 16, 2008 7:57 am

Fit those Dyna coils! I've had some on my A4 now for years. Highly recommended. P.

Rich · #14 PostAuthor: **Rich** » Sat Feb 16, 2008 9:09 am

Have you checked that the holes in the emulsion tubes are not blocked ?

misfiring a4

misfiring a4

misfiring a4

MISFIRING A4

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