GAZELLE BREAK-IN PROCEDURES

The break-in fuel should be mixed with 7 oz per gallon of Maxima 927Maxima 927 oil is in stock at SRS Engines
castor oil or other high quality racing 2-cycle lubricant. Set the carb slightly rich. The engine should be broken in with starting with 2-second bursts of full throttle followed by about 5 seconds of cool down part throttle. Gradually increase the length of the full throttle bursts until full throttle is applied for the whole longest straight after about 15 minutes of run time. The 15-minute break-in should be broken into three 5-minute sessions with a cool down period between each session.

CARBURETOR ADJUSTMENT

For racing set the carb to about 1.5 -turns on the low speed needle and about 5/8 turn on the high-speed needle. The rich low speed setting may require that the engine is started with 1 turn on the low speed needle and then opened up when underway. For best race performance set the low speed needle as rich as possible while maintaining max acceleration off the turns. Set the idle speed adjustment to maintain idle and to allow lubrication to continue to enter the engine when the throttle is closed at the end of a straight away. EGT normally peaks at about 900 degrees F during a race. These settings are guidelines and will vary with air density and track conditions.

If the engine slows near the end of a race, richen the low speed needle slightly to cool the engine. This will usually help maintain power in a long race. For more information see Racing Diaphragm Carb Operation.

CARBURETOR REBUILDS

The diaphragms in the carb gradually become stiff when exposed to fuel. The stiffness affects the carb’s ability to meter correctly. If your carb starts to require a lean setting to keep from flooding and then is too lean at hi speeds, installing new diaphragms will usually cure the problem. The diaphragms will be best when new and will usually work correctly for about two weeks of fuel exposure. If there is any doubt, replace the diaphragms.

SPARK PLUG

The Autolite AR51Autolite AR51 spark plugs are in stock at SRS Engines
gapped at .032” - .035” is an excellent plug for the Gazelle engine.

EXHAUST FLEX LENGTH

The engine will perform well with a flex length of 2-1/4” to 2-1/2”.

RACE OIL

Maxima 927Maxima 927 oil is in stock at SRS Engines
castor oil mixed @ 7 oz per gallon of fuel gives excellent lubrication, low deposit formation, and eliminates ring sticking. A name brand 93 octane super unleaded fuel runs well in these engines, but can cause piston seizure if run too lean. Race fuel with higher octane is more consistent and safer and will pass fuel tech.

CLEAN CARBON

The engine is set with combustion chamber volume at about 7.0cc. The legal limit is 6.5cc. Just .003” of carbon buildup on the piston top is 0.1cc. Be sure to remove the head and clean any deposits from the combustion chamber and piston top before any race after which the head cc’s will be tech’ed.

NOTE: When you remove the head from your Gazelle, torque it back in a crisscross pattern to 150 inch-pounds.

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