Hitchcocks Forum

Can someone shed some light on this?
I have just removed the fuel tank and observed some previous owner
has drilled and tapped a grease nipple into the top of the rocker box???
Any ideas why?

I've seen a few fittings added to Crusader rocker boxes, the idea seems to be to have extra breathing from the top of the engine. Not seen a grease nipple though, not sure much air would escape there!

REgards, Mark