Spark plugs - advantage of longer plugs?

[Colin Lindsay]

2 hours ago, NonMember said:

Ideally that's a head off job, as you don't really want bits of crud sitting on top of the piston.

That's for the winter layup. The Herald has been used regularly for what seems like the last twenty years by the (elderly*) owner who has forgotten oil changes, plug changes, and even antifreeze, so I'm servicing what I can but as always, anything changed or replaced disturbs something else - so it's going to be a busy winter. It's funny that I removed short plugs, then the first cross-reference I checked says long plugs, but they won't fully fit so I'll stick to short for now then find out exactly why when the head comes off. When I started this thread, the idea that the suggested plugs wouldn't actually fit wasn't even considered, hence the query on what the difference in the length would do to the running.

 

*if he ever finds out that I've called him that he'll probably do me harm.

[Pete Lewis]

a 14mm nut tap loaded with grease normally catches any debris , the unused  bit of thread gets as crusty as the combustion chamber 

then a 3/4" in a 1/2" plug hole just binds up 

Pete