#1 & #3 cylinders not working [CB750 1995]

[Bogs]

For a week, my valve head cover was leaking. So i decided to replace the valve head gasket yesterday.

Before i replaced the gasket, all four cylinders are working. After the replacement, #1 and #3 cylinders are not working, I know they’re not working because of the engine sound, the pickup when i rev it up and I checked all four exhaust pipes (#1 & #3 pipes are cold whilst the #2 & #4 pipes are hot.)

- so replaced fresh #1 and #3 plugs. Still not working.
- all four spark plug caps are tested and still working.
- carbs are working great, newly synced (last month).

What could possibly wrong?

Thank you for all the help.

 

[brettp]

Check your number 1 coil (left side of bike). Make sure the two electrical connections are good. Cylinders 1 and 3 are both fired with that same coil.

 

[Bogs]

Check your number 1 coil (left side of bike). Make sure the two electrical connections are good. Cylinders 1 and 3 are both fired with that same coil.

Wow!!! You’re a Life saver!!!

I didn’t noticed, i switched everything (the plug caps). What’s wrong was,

Plug 1 with cap 3
Plug 2 with cap 2
Plug 3 with cap 1
Plug 4 with cap 4

With your help, i checked the ignition coils and caps. And placed it to its proper plugs.

Thank you so much

 

[brettp]

Very welcome. Enjoy the miles!