Been looking at my 1990 cbr600 today, have no spark at all or fuel pump power. Ive tried live power to the pump and it works. Bridged rhe wire that goes to the fuel pump relay and that did kick the pump in so I know the kill switch works.

Ive got 12v at the coils + terminal. Ive checked and cant find any broken wires or fuses. The only thing I can think of is the cdi box but would that kill spark and fuel pump when you turn ignition on?

 

Have you checked the interlock? The side stand, neutral and clutch switches.

 

What do you mean by the interlock?
Its getting signal for neutral so I assume thats okay, ive tried it with the side stand up and down but in neutral wouldn't that discard the side stand anyway?

 

That's why it's an interlock :-)

The switches are interconnected so, yes, if it's in neutral and the neutral signal is connected to the ECU then you're OK.

 

Okay that makes sense, im not really clued up on bikes. Got a new cdi coming this week to try so hopefully that might solve it

 

Ive tried a new cdi and its exactly the same, no fuel pump and no spark. Ive got 12v still on both terminals on the coils but its still not switching. Ive got 12 at the fuel pump relay and the from the relay to the pump its not kicking out any power with 2 different fuel pump relays.

The cdi box I tried is from a 1994, could this cause no spark still. Im gunna try a new 1990 wiring loom and ignition seitxh to rule that out next

 

I have realised ive been testing only 1 coil. The coil leads loop over so the left hand coil does the 2 outer cylinder and the right coil does the inner 2 coils. My left coil is dead. Ive tried swapping the feed wires round for the coils and both time i had spark on the right coil but not on the left so a new coil should cure my problem.

I still however have no fuel pump prime despite having power to the fuel pump relay and tried a different relay. What else could cause spark but no fuel pump???

 

If the float bowls are full then the pump will not 'prime' as it would with an injected set up, so you may be overthinking this, sort the coils out and then see what happens. These bikes will work on gravity feed so if need be set up and auxiliary tank feed to the carbs.

 

Fitted the new coil and have spark. Fitted the fuel tank and bypassed the fuel pump relay. The fuel pump still works on the ignition and the kills switch so I think I'll leave it bypassed. Ive tried 3 fuel pump relays and all do nothing. The bikes run for the first time in 13 years so im happy with that. Just wanted to update the post and it is indeed possible to have spark without fuel pump.

Also for anyone looking into this I have read about putting 9v to the pink wire in the ignition to bypass a diode but mine doesnt have it so I assume 1990 models don't have that additional security feature. And finally I Fitted a newer cdi from a 1994 model and its worked fine.

 

Thanks for the update, brilliant that it is now running