BRP ski-doo MACH Z 1000 SDI, Handbook

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SECTION 11 - COMPETITION PREPARATION
MMC2005-001_11A.FM
11-15
STOCK CLASS PREPARATION
NOTE: Any machining and/or grinding is illegal in
stock class racing. Keep your machine legal !
1. Remove and disassemble the engine according
to correct Shop Manual procedures.
2. With the crankshaft resting in the lower half of
the crankcase, set up a dial indicator and check
the run out of the crankshaft at both ends. You
should see no more than 0.05 mm (0.002 in) run
out. If you have the capability, adjust the crank-
shaft as close to perfect as possible.
1. Measure behind the key
2. Measure at 6 mm (1/4 in) from edge
3. Set your cylinder base gaskets and cylinders on
the upper half of the crankcase, and lightly
torque the cylinders to the half. Be sure to install
exhaust manifold on the cylinders before tight-
ening them to the upper crankcase half to en-
sure the same position of the cylinders on final
assembly.
Check the match of the gaskets and cylinders to
the base; match them perfectly with a die grinder
in the areas of transfer port passages. Also check
for any over lap of the exhaust manifold gaskets
where the exhaust manifold joins the cylinders.
Before reassembling make sure that parts are free
of any dust or particles.
4. Check piston to cylinder clearances, ring end
gap, cylinder taper and out-of round.
5. Assemble the engine using the correct seal-
ants where needed.
Rotary valve timing should be set with the closing
edge as close to specs as possible or slightly higher.
NOTE: Refer to chart page.
6. The engine should be pressure-tested for air
leaks. It should hold 6 PSI for 6 minutes with
no more than a 1 PSI/min. Ioss.
7. Lube the rewind and inspect the rope for frays
or cuts.
8. Oval racing must use taillight, brake light ele-
ment on continuously (jumper from taillight
wire terminal to brake light terminal on taillight
assembly), regulator, tachometer, and temper-
ature gauge.
9. Synchronize carburetors so that they open pre-
cisely together and ensure that the cut aways
of the slides clear the inlet bores of the carbu-
retors. After carb. adjustment, adjust oil injec-
tion pump.
10. On RAVE valve-equipped engines, check for
free movement of the RAVE valve mechanism.
Check the passageways between valve piston
and exhaust port for any carbon buildup.
Adjust RAVE preload. It is better to have the valve
open a little earlier than later.
NOTE: Pump fuels can be oxygenated or contain
alcohol. Have your fuel tested prior to the race.
Do not use fuel de-icers.
11. Tie wrap ignition wire connectors together.
12. Adjust carburetors for atmospheric conditions.
(See ENGINE PREPARATION section).
13. Break in a new engine before racing it. Perfor-
mance can be gained by getting some run time
on the engine. Ten hours of break-in is recom-
mended.
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