BREAK-IN PROCEDURES

 

Sprint Instructions:

• The engine should be broken-in with starting with part throttle runs through the gears with light loading and low rpm. Gradually increase the length and loading of the pulls through the gears over a period of 5 minutes. Do not apply full throttle or rpm above 11,000 during this period.
• Cool down for 3 minutes and check for leaks and loose connections.
• For the next 5 minutes apply short bursts of full throttle in all the gears. Gradually increase the length of the full throttle bursts until full throttle is constantly applied in 1st thru 4th gear and intermittently thru 5th and 6th gear.
• Go racing.

Road Race Instructions:

• The engine should be broken-in with starting with part throttle runs through the gears with light loading and low rpm. Gradually increase the length and loading of the pulls through the gears over a period of 5 minutes. Do not apply full throttle or rpm above 11,000 during this period.
• Cool down for 3 minutes and check for leaks and loose connections.
• For the next 5 minutes apply short bursts of full throttle in all the gears. Limit the rpm to 11,000.
• Cool down for 3 minutes and check for leaks and loose connections.
• For the next 5 minutes apply full race power and rpm in 1st thru 4th gear out of each turn. Use part throttle and limit rpm to 11,500 in 5th and 6th gear until the next turn.
• Cool down for 3 minutes and check for leaks and loose connections.
• Go racing.

RECOMMENDED SETTINGS

CARBURETOR JETS
Always start rich and lean the jet until maximum performance is reached. Never run leaner than the maximum performance jet size. The maximum performance jet size will vary with weather conditions. If two jet sizes run the same, always revert to the richer jet.

 

In general for Senior 125 Stock start with a 175 main jet for ambient temperatures around 70 degrees and a 172 main jet for temperatures around 85 degrees. For SKUSA S3 start with a 172 main jet for temperatures around 70 degrees and a 170 main jet for temperatures around 85 degrees

IGNITION TIMING
Ignition timing can be varied by loosening the ignition stator plate retaining screws and rotating the stator plate. The stator plate is scribed with a mark for 0 degrees advance.  If the stator plate with the mark is removed, consult SRS before adjusting the timing.

PISTON
THE PISTON AND RING USED IN THIS ENGINE ARE STOCK HONDA. DO NOT USE OTHER PISTON/ RING COMBINATIONS BECAUSE OF DECK HEIGHT AND COMPRESSION VARIATIONS.

COOLING SYSTEM
Check the water level in the cooling system to verify that it is full. If the cooling system is allowed to run with too little water, the engine will overheat and damage to the piston and cylinder will occur. When filling the cooling system that has been dry, use distilled water and verify that there are no air pockets trapped in the water pump or hoses. If air pockets are left in the system, water may not circulate and the engine will overheat. USE REDLINE WATER WETTERRedline Water Wetter is in stock at SRS Engines
IN THE COOLING SYSTEM TO PREVENT CORROSION.

RACE FUEL & OIL
Maxima 927Maxima 927 oil is in stock at SRS Engines
castor oil mixed @ 6.0 oz per gallon of fuel gives excellent lubrication, low deposit formation, and eliminates ring sticking. Use only quality race fuel of 100 octane rating or above such as Phillips B32 or VP C12.

CLUTCH ADJUSTMENT
Adjust free play to approximately 3/8-inch to 1/2-inch at the end of the clutch lever. Limit travel to one inch once the clutch is engaged. More than that might allow the outer clutch friction disk to jump out of the clutch basket.

TRANSMISSION OIL
Use Redline Shockproof Lightweight Gear OilRedline oils are in stock at SRS Engines
. Do not use petroleum based ATF’s or gear oils. Change the transmission oil after initial break-in and practice on the first race weekend for a new engine and every 2 race weekends thereafter. Fill the transmission up to the sight hole with the engine level. That will require 650ml oil if your engine is new and/or dry. Refill with about 600ml, for routine oil changes.

SPARK PLUG
The stock spark plug connector contains an internal resistor so a non resistor plug can be used. Start with an NGK B10egNGK B10eg spark plugs are in stock at SRS Engines
or equivalent heat range spark plug. {modal url=http://www.superkartsusa.com/dmdocuments/2009-2010-SKUSA-RuleBook.pdf|type=greybox|width=700|height=600}S5 Engines{/modal} will do well with a NGK B9egNGK B9eg spark plugs are in stock at SRS Engines
.

IGNITION COIL MOUNT
The ignition coil should be mounted in a way that isolates it from engine vibrations. There are several anti vibration mounts available or that have been improvised by karters. That isolates the coil from vibration and keeps spark plug wires short.

 

Keep the ignition module at least 5 inches from the ignition coil and sparkplug wire. The seat back is the preferred place to mount the coil. The two wires leading from the CDI module must be lengthened to reach from the CDI to the coil.

 

Connect a grounding wire between the laminated core of the coil and the engine crankcase.

Engine Mounting
See the Engine Mounting Article.

 

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