non starting nc23

[cbr_scott]

hi there guys, iv had a read through the boards but cant seem to find any help to this, well the problem started back when i first got the bike about 4 months ago, it was running fine so i stripped it down for some work,carb clean, setup ect... so after all that i rebuilt it and she fired up again no problems then just cut out and wouldnt restart so after replacing alot of eletrical components i.e coils,pick up coils, cdi unit, i then changed the spark plugs to get her going, and again she sparked into life again, iv since used her every day with no problems both to commute and long rides, them the other day i got to work parked her up but when i finished my shift i went to start her and she wouldnt start, i then got her into the workshop and got her stripped down again to start diagnoising the problem, it turns out i have no spark again the same as last time, so i have tried another know good spark plug in all leads but still no spark, iv checked all fuses, wire connections tried my other cdi but still no spark i then noticed that while cranking the fuel pump wasnt pulsing, so i check the pump out and it works fine with a direct feed, so iv traced the fault down to the fuel cut off relay, when i bridge the relay the pump runs so the haynes says the relay is faulty, so my question is how does the relay affect the spark?? and when i phoned honda to get a new one the guys having problems finding it on the fiche so i had a look myself and cant work it out either so c'mon guys please help...

sorry about the long post but i find it better to give as much info as possiable

[Matchlessman]

Hi Scott,

ive not got a haynes diagram to hand (my manual was left out in the rain about a year ago and ive not got round to replacing it) and im not that good at electrics, but ive had my triarm apart with electical problems a fair few times but i dont recall a fuel cutoff relay. :S

You say that the fuel pump will pulse if you bridge the relay, how fast does it pulse? mine on tickover pulses really slowly but it didnt seem to pulse until the engine was running.

have you tried for a spark whilst having the relay bridged?

If its a general spark issue, it might be worth having a look at the pulse generators? From the testing youve done its not likely to be a crap connections etc

[cbr_scott]

Hi Scott,

ive not got a haynes diagram to hand (my manual was left out in the rain about a year ago and ive not got round to replacing it) and im not that good at electrics, but ive had my triarm apart with electical problems a fair few times but i dont recall a fuel cutoff relay. :S

You say that the fuel pump will pulse if you bridge the relay, how fast does it pulse? mine on tickover pulses really slowly but it didnt seem to pulse until the engine was running.

have you tried for a spark whilst having the relay bridged?

If its a general spark issue, it might be worth having a look at the pulse generators? From the testing youve done its not likely to be a crap connections etc

hi there matchlessman

im glad im not the only one then with eletrical problems
i have replaced the pulse pick up coils, and still no joy..
what i havent done tho is bridge the relay and try for a spark at the same time, once bridged the pump pulses realy quickly and flows lots of fuel..

the fuel cut of relay is a safety device and is connected to the fuel pump and the coils, what its function is i dont exactly know i could explain the wiring lay out if it helps you any, as im stumpped, im not sure if the relay needs to see a pulse from the coils to eniergize the pump or the relay switches the coils and the cdi sends the pulse..
the relay is not your conventinal relay i opened it up to have alook

i thought i would had more help on this on
but cheers anyway

[Matchlessman]

Hi Scott,

Bike electrics are everyones nightmare so it doesnt surprise me that you havent had many replies.

It might be worth giving Graeme France a call and having a chat with him, theres probably a backfeed frome something that energises/activates something else thats crucial for a spark. Graeme is pretty much the guru on our bikes so would probably be able to give you much better advice than anyone.

[Incognito400]

Fuel cut off relay is a saftey switch that only puts out to the fuel pump if the engine is running. It has connections going to the coils (so I'm guessing if the coil gets nothing, neither does the fuel pump). Apart from that no idea how it works

Wouldn't have thought relay would have any effect on spark - if in doubt just unplug it and double check. Bike will run (apallingly badly) without a fuel pump.

Disclaimer: I know nothing....