Most motorcycle problems are caused by the nut that connects the handlebars to the saddle.

Spark issues - not a cb500

Share
avatar
Jameshambleton
Moderator
Moderator

Posts : 1871
Location : Bedale, North Yorkshire

Spark issues - not a cb500

Post by Jameshambleton on Wed 03 May 2017, 8:59 pm

So I've acquired a gpz500 as a none runner from a friend previously stolen recovered 4 times!  Shocked

I've tried to start it and found it hasn't got any sparks from either coil. 

I've fully charged and tried 2 different batteries, cleaned the spade connections on the coils and checked the connections from the pickup going into the loom.

I've tried a different set of coils from my cb400sf and I'm getting the same result, and I have tried grounding the spark plug to a clean bit of metal on the engine with no avail from either the cb400 or the gpz coils. suggestions?

I've ran a multimeter inline with one coil and it was reading 5v but now the leads on my cheapo multimeter have had it so I can't test anything else oh and the fuses are ok

Suggestions?
avatar
ANDYC
the 900
the 900

Mechanic
Posts : 771
Location : Windsor

Re: Spark issues - not a cb500

Post by ANDYC on Thu 04 May 2017, 8:33 am

It may be the ignition pick up coil. The one that reads the timing from the trigger wheel on the crankshaft.  Or possibly the CDI unit.
avatar
Pukka
Crotch Rocketuer
Crotch Rocketuer

Posts : 34
Location : Woking, Surrey

Re: Spark issues - not a cb500

Post by Pukka on Thu 04 May 2017, 2:30 pm

ANDYC wrote:It may be the ignition pick up coil. The one that reads the timing from the trigger wheel on the crankshaft.  Or possibly the CDI unit.



What year model it it? I believe the pre 1994 models had an issue with the alternator magnets which could take out the ignition pickup coils if they went as above.
avatar
Jameshambleton
Moderator
Moderator

Posts : 1871
Location : Bedale, North Yorkshire

Re: Spark issues - not a cb500

Post by Jameshambleton on Thu 04 May 2017, 3:45 pm

Pukka wrote:

ANDYC wrote:It may be the ignition pick up coil. The one that reads the timing from the trigger wheel on the crankshaft.  Or possibly the CDI unit.

What year model it it? I believe the pre 1994 models had an issue with the alternator magnets which could take out the ignition pickup coils if they went as above.

Mine's the 94 model so it shouldn't suffer from that issue. It's the mk2 so it shouldn't be affected as it was the mk1 that suffered from that issue afaik. 
I'm waiting on some new leads for my multimeter and then I'll try again. I rechecked the fuses today and they were all intact.
avatar
eternally_troubled
Admin
Admin

Awesome!
Posts : 3680
Location : 'ere be fens. (near Cambridge)

Re: Spark issues - not a cb500

Post by eternally_troubled on Sun 07 May 2017, 7:48 pm

When the multimeter bits come I'd certainly test that there is some kind of continuity to the ignition pick-up coil - if you are luky then the Haynes (or whatever) might list a nominal resistance (suffice to say it should be less than infinte!).

Also - you could try (v briefly!) connecting 12V (probably better with 6V) across the coil then removing it - should cause a spark across the spark when you remove the supply.
avatar
Beresford
the 900
the 900

Posts : 1445
Location : not that far from Kirkistown

Re: Spark issues - not a cb500

Post by Beresford on Sun 07 May 2017, 8:54 pm

On Gumtree there's a stolen recovered 2003 GPZ500S for sale near me, less than 20K miles. Asking £300 or offers. Would that be worth a look. No doubt it needs work, at least a new lock barrel and key.
avatar
Jameshambleton
Moderator
Moderator

Posts : 1871
Location : Bedale, North Yorkshire

Re: Spark issues - not a cb500

Post by Jameshambleton on Mon 08 May 2017, 5:59 pm

Ok so I've found the issue, on the ignition barrel there is a 500 ohms resistor. When this is powered the signal goes to the cdi that controls the coils. When the bike is hot wired the resistor isn't present so the bike won't start as the cdi isn't telling the coils to fire the spark. 

Now my option is a new ignition as this one is also after market so the socket wiring points are in different locations, so I can't solder on the connections as I had hoped.
avatar
eternally_troubled
Admin
Admin

Awesome!
Posts : 3680
Location : 'ere be fens. (near Cambridge)

Re: Spark issues - not a cb500

Post by eternally_troubled on Wed 10 May 2017, 9:26 pm

Jameshambleton wrote:Ok so I've found the issue, on the ignition barrel there is a 500 ohms resistor. When this is powered the signal goes to the cdi that controls the coils. When the bike is hot wired the resistor isn't present so the bike won't start as the cdi isn't telling the coils to fire the spark. 

Now my option is a new ignition as this one is also after market so the socket wiring points are in different locations, so I can't solder on the connections as I had hoped.

Is that, by any chance, an anti-hotwiring resistor? :) You could always move the resistor into the loom and use a different type of lock/switch...

Sponsored content

Re: Spark issues - not a cb500

Post by Sponsored content


    Current date/time is Fri 20 Oct 2017, 3:11 pm