Rave Valve Adjustment; Available Rave Springs; Rave Valve Maintenance - BOMBARDIER 1996 Ski-doo MX Z440 Handbook

The 583 RAVE has, in effect, two ports. Let's compare them separately. With the RAVE valve open,
the exhaust port timing of the 583 and 537 are identical with a total open duration of 202°. The
exhaust port of the 583, however, is 1 mm (.039 in) wider than on the 537. When the RAVE valve
closes, the exhaust port timing of the 583 matches that of the 467 with a total open duration of
189°.
C) ADJUSTMENT
The red cap on the RAVE valve cover should be turned all the way in and bottomed in normal use.
Backing the red adjuster out will reduce the spring preload and allow the RAVE valve to open at a
lower RPM.
At high altitudes, exhaust gas pressures will drop and the spring preload may have to be
decreased. It is doubtful that any adjustment will be required up to an altitude of 2400 m (8000 ft.).
Above that, however, the spring preload can be reduced by turning the red adjustment screw out
up to a maximum of four turns.
The only other time adjustment of the spring preload should be considered is if the engine has
been modified in any way.

AVAILABLE RAVE SPRINGS :

Year
94
95
96
Optional
D) MAINTENANCE
There are no wear parts anywhere in the system and there are no adjustments to be periodically
checked. The only possible maintenance required would be cleaning of carbon deposits from the
guillotine slide. Cleaning intervals would depend upon the user's riding style and the quality of the
oil used. Using Ski-Doo or Blizzard oil, we would suggest annual cleaning of the valve. If a
customer uses a lower quality, high ash oil, more frequent cleaning may be required.
No special solvents or cleaners are required when cleaning the valve,
04-26
Rotax Part number
779 420239941
670
583
779 420239941
670 (one pipe)
670 (two pipe)
583
599
454
All models same as 95 specs except
454 420239945
420339942
420339944
Free length
52.5 mm
48 38.0 mm
48 38.0 mm
52.5 mm
46 42.0 mm
48 38.0 mm
48 38.0 mm
40 48.5 mm x D.8
47 42.0 mm
48.0 mm
42.5 mm
48.5 mm x D.9