I bought a pair of 18mm’s from the GSP co some years back for a French single I was renovating at the time, and they both failed to fire the engine as they weren’t sparking. I contacted the GSP people for a refund and he wouldn’t issue one as apparently I hadn’t “followed the procedure”.
This (he said) meant starting the bike on the old plugs then removing it/them and putting in the new ones while the engine is still warm.
“But this is a rebuild and I never had any old plugs” to which the answer was “tough, you’ve sooted/wetted the plugs under the insulator nose now and they’re useless”.
Tried all the usual methods of cleaning them but to no avail.
They have a good range of stuff but I avoid them now. Another customer lost…
