I can't get the threads to catch and I can't feel any thread at all.

Before I start tearing stuff apart I thought I would see if anyone has any clever tip to fix this.

Assuming I pull the manifold and tin and clean out the orange crap, is it OK to use a thread insert here?

I swear this motor has some DPO bodge on every part.

I think a thread insert is the only choice, at least until the motor is rebuilt. Either a coil or a Time-sert would work. It may affect the reading ability of the CHT sensor a little. On a rebuild, swap heads and drill & tap a new hole; better yet, have a machine shop do it.

It just keeps getting worse. The area around the sensor loks messed up to me. Isn't there supposed to be a boss that the hole is drilled into so that the sensor screws in flush.

Here's a picture:


Note the traces of orange RTV that was used to hold the sensor in. I'm amazed it ever ran like that.

Try again on picture.

dude,
you almost there...get a used head and replace it...

It will be faster and better in the long run.

Rich