Question on Spark Plugs

[herclepercle]

Hi All. I'm new

I have recently acquired a K10 1990 1.2 GSX. It has been a little beauty (apart from the clutch completely giving up in the countryside - ouch!).

It does have an issue with misfiring at present. I have replaced the air filter and have bought new spark plugs. They are NGK BPR5E. I've noticed some places specifying BPR5ES - should I be alarmed that mine doesn't have the S? Taking it to my dad's to sort out the spark plugs but it's quite a way so I don't want to waste the journey

P.S. I'll put some pics of "Bucket" up as soon as I've taken some

 

[h701micra]

They'll be fine to reassure yourself put the new beside the old and compare

 

[herclepercle]

Cheers

Should this sort out the problem? Anything else I should check for?

 

[h701micra]

Misfiring will be linked to the electronic side of things.
So it could be spark plugs, ht leads, distributor cap, rotor arm.

Very doubtful its the distributor, king lead or coil

Changing the first 4 items is a good way to eliminate most electrical issues