Breather Reed Valves - Crankcase - +0.030" Oversize - Evolution Big Twin '93-'99 MUC-OFF Aluminum backing plate that features

Aluminum backing plate that features zero flat surfaces

Includes a fitted rain cover specially designed to protect the seat from water and dirt

Easy bolt-on installation

blow by and oily air cleaners

Drilled for mounting in different positions: 90 degree

Breather Reed Valves - Crankcase - +0.030" Oversize - Evolution Big Twin '93-'99 MUC-OFF Aluminum backing plate that featuresBreather Reed Valves Crankcase +0. 030" Oversize Evolution Big Twin '93 '99 New style breather is not dependent on the rotation of the crankshaft to make it open and close. Instead, reeds open when pressure in the crankcase becomes greater than pressure in the cam chest, and close when pressure in the cam chest is equal to or greater than pressure in the crankcase By opening and closing "on demand," the reed valves automatically compensate for lag