Rotax V990

General Specifications

Weight

The December 2001 V990 workshop manual lists the engine weight as 143 lbs. The October 2003 V990RR workshop manual lists the engine weight as 148 lbs.

Displacement

According to the December 2001 V990 workshop manual:

RSV, RSV-R Tuono, Mille
	Up to 2000	997.6 cm³
	2001 and later	998.00 cm³
SL Falco
	Up to 2000	997.6 cm³
	2001 and later	998.0 cm³
RST Futura
		997.62 cm³
ETV Caponord
		998.00 cm³

Compression Ratio

RSV, RSV-R Tuono, Mille
	Up to 2000	11.4±0.5:1
	2001 and later	11.8±0.5:1
SL Falco
	Up to 2000	11.4±0.5:1
	2001 and later	11.8±0.5:1
RST Futura
		11.8±0.5:1
ETV Caponord
		10.4±0.5:1

Slipper Clutch

Pneumatic Power Clutch/slipper clutch/PBTL System details are in this apriliaforum post.

PBTL SYSTEM

The PBTL system on the RSV 1000 reduces the ‘braking’ torque transmitted by the engine during deceleration.

OPERATING PRINCIPLE:

Line 1 is connected to the intake passage whereas line 2 – downstream of the retaining valve – is connected to the airbox via the throttle valve. Line 3 links line 2 to the airbox when the throttle valve opens to an angle greater than 10-12 degrees.

During deceleration, the system configuration is as shown in the figure.

The negative pressure in the intake passages is transmitted to the clutch membrane via line 1+2.

The ‘retaining’ valve (non-return) comes into play and stabilises the pressure in the line.

Consequently, the clutch discs slip and reduce the torque.

During acceleration (throttle valve >12°), the valve, connected on the throttle unit axis, links up line 2 with the airbox, thus cancelling out the pressing effect on the clutch unit and taking the clutch pack back to its original position.