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ZX10R starts sort of.
roadrunner - 6/7/20 at 03:30 PM

Got my regulator sorted and all plumbed in.
Engine starts and seems to run but noticed that it shakes slightly.
Turns out that it's only firing on cylinders 2 and 3.
1 and 4 primary pipes stay stone cold.
I have a spark to 1 and 4 and the plugs seem wet from fuel but I'm at a loss why they don't fire.

Any ideas I could look for.



steve m - 6/7/20 at 05:15 PM

Swop the leads on 1 and 4, ?

and try again


adithorp - 6/7/20 at 06:13 PM

Is it individual coil on plug or twin coil packs feeding 2cylinders each? Do you have sparks on 1+4?

roadrunner - 6/7/20 at 06:33 PM

Thanks fellas.
Because of the layout of the loom its difficult to get them wrong way round.

There are 4 coils like in all modern engines and there is a spark on those that are not firing.

adithorp - 6/7/20 at 08:03 PM

Try listening for the injectors operating with a screw driver. You should hear a click.

roadrunner - 6/7/20 at 09:44 PM

Originally posted by adithorp
Try listening for the injectors operating with a screw driver. You should hear a click.

I guess you rest the driver on the injectors as they operate.

adithorp - 7/7/20 at 06:37 AM

Yes. A long thin screwdriver is best. Rest the tip on what you want to listen to and the handle against your ear.

russbost - 7/7/20 at 07:32 AM

before spending loads of time on anything else I would try swapping the plugs from 2 & 3 with the ones from 1 & 4. If it's anything like other modern bike engines, if it's fouled the plugs it won't "unfoul" them. Would be very odd to have spark on all 4 & injectors only working on 2, plus you say plugs look wet, so sounds like it's getting fuel

roadrunner - 7/7/20 at 01:07 PM

Hi Russ.

I have tried different spark plugs.
I will try swapping plugs and coils though.

roadrunner - 19/7/20 at 04:50 PM

Hi fellas.

It now runs in all 4 cylinders.
I ended up taking the injectors out. Tested 1 that wasn't working, just put 12v through it alternating the current then swapped them over. At this point I had achieved 3 cylinders firing.
Took out the last one, put 12v through it and it seemed to be stuck. After a few swapping around of the current it started working.
All back together and working fine.

Thanks all.

adithorp - 19/7/20 at 05:06 PM


Might be worth sticking some injector cleaner in the fuel just to get rid of any residual lacquer. Forte is good or Wynns if you can't get.

roadrunner - 19/7/20 at 05:41 PM

Already done that.;-)