2004 FZS1000 Not running on all cylinders.

[CountFazer]

Hi All,

My bike isn't firing on all cylinders.
At first cyl 1 didnt fire from cold sometimes. I swapped the spark plug cap with cyl 4 to try isolate the problem. Left it for a couple of days. Then when I started the bike cyl 3 was not firing.

I've now checked ignition coil resistance, spark plug cap & lead resistance and they were all normal. When I plugged everything back together, cyl 2 & 3 were not firing. I then swapped the plug caps around some more but still cyl 2 & 3 not firing.

However, if I pull the plug caps off the spark plugs a bit so that they are loose, the cylinders fire!

Any ideas would be greatly appreciated.

Cheers,
CountFazer

[Trebus]

If you suspect electrical then probably be carbs and vice versa!

Has it been laid up? Could the pilot jets be blocked? Sometimes a run through with some carb cleaner additive can work but only ever had limited success. 

Sounds like you might be chasing your tail somewhat. Usual advice will be to cut a few mm of the end of the HT leads to ensure you have a good connection.

[CountFazer]

If you suspect electrical then probably be carbs and vice versa!

Has it been laid up? Could the pilot jets be blocked? Sometimes a run through with some carb cleaner additive can work but only ever had limited success. 

Sounds like you might be chasing your tail somewhat. Usual advice will be to cut a few mm of the end of the HT leads to ensure you have a good connection.

Hi Trebus,

I inspected the plugs for cylinders 2 & 3 and they were both fouled and not sparking properly, so I replaced them.
After that all cylinders were working. I also replace plugs for 1 & 4 for good measure.

The carbs were cleaned about 9 months ago (3000 km ago). Maybe the mixture screws were not set correctly.