A while ago I ran out of the wide copper spark plug washers and was using cheapies out of a kit. I found one washer decided to grow and thus would have been a poor seal. I have on order more champion washers from USA (AS&Sco) and look forward to replacing same ASP. Also the larger washers transfer heat better I am told. I think like most I use 2 washers under plugs (one where there is a CHT sensor). I have heard you have the sensor between plug and extra washer - Anybody know?
Ian M
