Running on three

[SMARTY]

So i was wondering how to test my coils, my project is at that stage were everything is toghether but is running on two, then found one coil wires the wrong way around. Now running on three. Carbs are rebuild and clean. Os it possiblw for the coil to be damaged were it only fire o. One lead? Thanks for any help

[wraith]

Mostly if a coil is not working it won't work on ever lead (there can always be a one off ) 

My first checks would be,

Remove spark plugs, 

Check each plug in ht leads and see if you're getting a spark on all plugs on all leads.

Could be as simple as one plug is fu*ked with it being flooded. Had this myself with new plugs but I'm finding there are a lot of bad plugs out there these days (NGK) 

[SMARTY]

Thanks, i have not changed the plugs. I will do the checks , thanks alot. 

 

 

[Upshotknothole]

As they said, really rare for a coil to only half die. You can try swapping the leads from the coil between the two plugs, see if the non running cylinder moves or not. Could be a bad lead if it does move. They get pretty hard and brittle with time.

[gsxwill]

On 8/22/2023 at 6:31 PM, wraith said:

Mostly if a coil is not working it won't work on ever lead (there can always be a one off ) 

My first checks would be,

Remove spark plugs, 

Check each plug in ht leads and see if you're getting a spark on all plugs on all leads.

Could be as simple as one plug is fu*ked with it being flooded. Had this myself with new plugs but I'm finding there are a lot of bad plugs out there these days (NGK) 

As @wraithsay there are a lot of bad plugs out there at the moment , picked up 12 last week 2 were bad 

[wraith]

2 hours ago, gsxwill said:

As @wraithsay there are a lot of bad plugs out there at the moment , picked up 12 last week 2 were bad 

I had a time not long ago where I was going to sell my kat, as it kept dropping into 3 cylinders and never the same cylinder that went down. Change plugs with new ones more time than I can remember. Did all the standard checks and all came out to be good, not until I started making the plugs that didn't work after a thought miles I figured out I had a lot of bad luck with getting  faulty plugs. So the kat was kept  I now avoid  buying NGK plugs unless I have no choice 

[SMARTY]

31 minutes ago, wraith said:

I had a time not long ago where I was going to sell my kat, as it kept dropping into 3 cylinders and never the same cylinder that went down. Change plugs with new ones more time than I can remember. Did all the standard checks and all came out to be good, not until I started making the plugs that didn't work after a thought miles I figured out I had a lot of bad luck with getting  faulty plugs. So the kat was kept  I now avoid  buying NGK plugs unless I have no choice 

What plugs do you use

[wraith]

Denso. 

They are dearer than NGK but I've not had a bad one, yet. 

[Captain Chaos]

Same here, at work we buy Denso plugs and no problems with bad ones. 

[Nick]

What is the denso jr9b equivalent?  Looks like x27etr?

I too have had issues with ngk quality - even when buying them from supposedly reputable places...

[wraith]

1 hour ago, Nick said:

What is the denso jr9b equivalent?  Looks like x27etr?

I too have had issues with ngk quality - even when buying them from supposedly reputable places...

Yes, for b12 and gsxr1100

[SMARTY]

Well, we will see today how it goes. I got ngks just to replace the old ones for now They are atleast 16 years old from sittiing in a dark gloomy wet scottish garage where i saves this motor from. So i tend to find the problem today. I will get sime denso plugs also. Thanks for the help.