So, who uses centre plug heads?

[Donnie]

and is it too much hassle getting at the plug if you are using a full frame body? ie not a cutdown?

[Warkton Tornado No.1]

Centre plug heads (on the centre axis) have all needed the back damper off in my experience; hence they only tend to get used in competition where the format offers benefits in terms of manufacture/modification. Sometimes a normal length ceramic cannot be accommodated & special low profile plugs have had to be sought.

Offset combustion chambers are not unique to Lambrettas (or V*spas) as there are advantages to moving the bowl to the cooler side of the barrel.

[Donnie]

Hmmm cheers for that WT something to think about. Its on the gt186 which doesnt have an offset bowl which is partly why Im considering going to the centre plug position.

[Warkton Tornado No.1]

I’ve thought some more about the issue of plug removal & wonder whether a dedicated low profile wrench might be use-able, although the cowling may be a restriction, even if you can get the plug cap off.

Spark Plug Wrench.JPG