Hi All

Putting together a 8E trialer. Have obtained a two hole head however one of the holes is oversized.  I always thought the decompressor was same size as standard plug. Anyone know if this is any use for my build, or simply use the standard head.

Thanks in advance

it was probably stripped, it was common at one point to open out rethread and put a slave in. Now it would be helicoiled

Good point.  That could be the answer. Thanks

I've got a feeling the Villiers decompressor thread is bigger than spark plug size, if it's the same as a 32A I've got one in the garage somewhere, I'll seek it out tomorrow. I'm just up the road from you in Fontmell..... 

Wow . That would be great.

So the 32A decompressor I have has a thread of 0.700 inch (od) or 17.80mm in new money, and is 18 tpi as best as I can make out. Villiers Services do sell a blanking plug to take the valves' place if you don't want to use one, but they're handy on muddy drops!

Thanks for the effort. Will take a look this evening. If suitable are you selling?

I've sent you a PM.