Kawasaki trade marked '
Electrofusion' process - was said to be nikasil (nickel silicon) at the time (
sic magazines) but may have been a molybdenum+steel (hard chrome?) coating fused to the cast aluminium cylinder bore
Kawasaki changed the process and/or composition in 2003 (and perhaps also at some other time in between)
I recollect them (OEM new) to be hard and shiney and mildly rustable (less likely to be nickel composition?) - replated ones usually dull with cross hatched hone for better lubricity
>2003 = KHI MX cylinders with composite of nickel-phosphorous alloy, inorganic materials like ceramic, silicone carbide and some organic materials
different replating outfits can offer different plating materials: such as Cermets - combing ceramic (hard particles) in a metal matrix (soft)
Aptec and replating:
http://kr-1s.co.uk/forum/viewtopic.php? ... 003#p49944
Motorcross and Off-Road Motorcycle Performance Handbook - Eric Gorr
"There are three types of plated cylinders, Kawasaki Electrofusion, hard-chrome, and nickel silicon carbide. There are several variations of the nickel silicon carbide process but the most common trade name is Nikasil. The nickel-based processes have many advantages over hard-chrome, Electrofusion, and sleeving. Nickel attracts oil and is an excellent carrier material for silicon carbide particles, a wear resistant material that carries the load of the piston. This material is electro-plated right on to the aluminum cylinder for the optimum thermal efficiency. Nickel can be honed with diamond stones which leave distinctive peaks and valley scratches in the cylinder wall which retain oil and provide a certain bearing ratio between the running surfaces of the bore. It's possible to rebuild a plated cylinder by fitting it with a sleeve. However you can expect to pay more for bore maintenance over the life of the bike, and lose thermal efficiency and horsepower. Plated cylinders are harder and last longer than sleeved cylinders. Kawasaki cylinders with the original Electrofusion coating or hard-chromed cylinders can be repaired with nickel plating or sleeving"
1979 air cooled KX250...Cycle World January 1979 <<< click
Six explosions of l.l5mm molybdenum wire using 16.000 volts and nine explosions of 1.6mm carbon-steel wire using 13,000 volts produce a porous Electrofusion surface approximately 0.070mm thick. The thin coating transfers heat very quickly enabling closer cylinder to piston clearances