I bought, at considerable expense, 200 rocker box gaskets from the OE manufacturer of Moto Parilla gaskets.
These I can supply in pairs as an alternative to buying a complete engine set.
Having supplied such gaskets to one gentleman I was surprised to get an email of complaint.
” Those darn gaskets don’t work, my engine still leaks oil; I want my money back! ”
Unfortunately, until the “smart gasket” is invented which can accommodate bowed & uneven mating faces we will have to continue to ensure the faces we want to joint are flat & can be drawn up parallel with the gasket between them.
You need a surface plate, a sheet of #800 grit 3M abrasive paper, some light oil, a deal of patience & when fitting the covers to the head a degree of mechanical sympathy.
Firstly attach the paper to the surface plate then perform a couple of “figure of eight” circuits using very light pressure. High spots will be revealed caused by the cover being deformed by overtightening of the fixing screws. Work the cover until an even matt finish is achieved using a few drops of oil on the paper. It is now flat and with a fresh gasket & an appropriate amount of leverage applied to the fixing screws it will not leak.
Go gorilla & it will. I don’t give refunds for “leaky gaskets” :o)