I have a leyland 400 in an Albion CD65 1970 model

The motor in my Albion CD65, a leyland 400 and I have a problem that the motor has over revved a few times to 3400 rpms checked oil levels etc, all looks ok including linkages, anyone had similar problems

What pump is it..a MiniMec ?......see if anything in the rack or plungers is sticky,one cause can be a sticking fuel unit.......might also be partial miss on that cylinder......,might also be a screw coming loose......take the cover plate off and have a look.......a lot of those pumps run better if you fill the sump with heavy oil every sixmonths or so......this fix was recommended by Leyland in the 70s.......I have many service bulletins from Leyland Australia.

John. .. please explain??? Filing the sump with heavy oil????..... and run with it?.. how / what will this achieve? EMNTK... my ignorance is deafening.

Oops....fill the pump with heavy oil.......in the cambox,which is normally lubricated by diesel leaking past the units........I recently did this with an old Hino,wasnt overrevving,but putting heavy oil in the pump improved running a lot......the leyland pumps were prone to cam and lifter scoring running on diesel......anyway ,diesel is a lot thinner than it was then....more like kero now.