The plug colour looks good, John, nice and tan with no black bits, was the tip just melted as opposed to broken? If the piston crowns don't show any sign of pitting due to any localized melting, colder plugs may be the answer. The NGK BR7EFS plugs with a 0.9mm gap may work better and are quite cheap, they hold up well on my R400D for track use, sometimes for full 1 hour sessions in high 30C ambient temperatures.
Thanks. I did read that but struggled to get a conclusion. I just ordered what caterham had on their site. Sounds like your choice might be less brittle.
The plug colour looks good, John, nice and tan with no black bits, was the tip just melted as opposed to broken? If the piston crowns don't show any sign of pitting due to any localized melting, colder plugs may be the answer. The NGK BR7EFS plugs with a 0.9mm gap may work better and are quite cheap, they hold up well on my R400D for track use, sometimes for full 1 hour sessions in high 30C ambient temperatures.
James
OK. Maybe I'll swap to them then.
People are saying they got too hot.
UFO7 WTF? , UberNiche printed stuff
Here is a link to a thread on 6 plugs I tried in the R400D back in 2017, before sticking with the BR7EFS since then: https://www.caterhamlotus7.club/comment/2228320#comment-2228320
James
Thanks. I did read that but struggled to get a conclusion. I just ordered what caterham had on their site. Sounds like your choice might be less brittle.
UFO7 WTF? , UberNiche printed stuff
The plugs James listed are better suited to your usage and are a grade cooler,
I would also consider a cylinder leakage test as 125 is very low, wondering if a portion of the errant electrode kissed a valve on its exit...?
Not sure which way you number them but No1 is a the front on the Duratec