Bit by the bad plug theads in both heads

[JerryCPP]

I screwed up one of my heads by trying to install a timesert where one had already been installed. (Too late at night, too tired, to dark to notice.) The second one went in crooked. I had to have the hole helicarced and rebored. The cost was so close to a new head, I'd recommend a new head. The EMPI heads Sonex sells now are far superior to the original and the MOFOCO heads. Nice heavy casting, cooling holes bored where the old ones were blocked, and great workmanship throughout.

[lutorm]

In case anyone runs into the same problem: It worked fine to Timesert a previously helicoiled spark plug thread. The insert cutter did not cut an entirely new thread (the helicoil thread appears to be the same pitch as the Timesert one, which I guess makes sense, they're the same pitch as the original thread) but the insert screwed in and locked in place OK.

Whoever did the helicoils did not make them aligned with the preexisting seat, though, but the new seat cut by the Timesert seat cutter fixed that. It just had to be cut a bit deeper than one would have hoped.