APPLICATION:
1984-98 1340 BT
FXR 1984-1994
FXD 1991-1998
FLST 1986-1998
FLT 1984-1998
FXST 1984-1998

DETAILS:
Keith Black flat top piston set is .020 oversize with an 8.6:1 compression ratio for 1984-up Big Twin Evolution models.
The Keith Black 390 hypereutectic alloy is cast in a permanent steel mold which makes it possible to build a light weight piston that makes more power and uses less fuel and lasts longer. Pistons are .020 over sized, for a 3.498" bore and has a 8.5:1 compression ratio. The low heat transfer of the alloy keeps the skirts cool so piston expansion is minimal. The combination of a low heat transfer piston alloy and high compression ring placement increases power and economy. The high ring placement alone reduces detoantion and increases the top ring temperature. **Note:Run engine at moderate speeds for at least 500 miles, avoiding excessive running in lower gears, in order to properly break-in new pistons and rings.

UOM: SET

TECH NOTES:
No replacements rings available through Biker Parts Superstore. Use Hastingsring # 2KB258.020.