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here are three selections; Street/Stock, Mild and Performance. Select the cam that best suits your application.

NOTE: If lobe separation angle (LSA) is less than 108° you may need to go to the next larger cam profile. If cam duration is longer than 250° the Atomic EFI will not be suitable for your application.

Yes, with the addition of a MSD PN 6010 box, it can handle the fuel delivery, but not individual coil spark. If you are running a front mount distributor and single coil, you will be able to use timing control with an ignition box.

No. The annular rings on the Atomic throttle body are designed by MSD’s engineers to work as special injector nozzles. The rings are not in a venturi and at no time does the fuel get pulled out because of low pressure. They help to spread the fuel out and have been shown to improve per cylinder fuel distribution. Even cylinder distribution, like that from a carburetor, helps make more consistent high rpm horsepower.

The fuel system configuration is very important. The common setup will not work on the Atomic EFI. Please see Diagram below:

An Air Fuel Ratio is the volume of air per each unit of fuel put into the engine. 14.7 units of air per 1 unit of fuel is “stoichiometric” meaning there is the exact right amount of air available to burn all of the present fuel. A lower AFR number means there is less air to match the fuel, and therefore the engine will run “Richer”. Oppositely, a higher AFR number means that there is more air to match the fuel and the engine will run “Leaner”.

A magnetic, points or standard coil negative will work, but not a hall-effect 5V signal. The signal out of any MSD distributor or MSD Ignition Control Unit will suffice to supply an RPM signal for the Atomic. NOTE: An Ignition Control Unit is required with most applications.

Yes capacitive discharge type ignition systems are compatible.

Why the switch from analog to digital? The main advantages of a digital ignition are: accurate timing; smaller ignition box size; full access to the timing curve via dip switches; you can change the initial timing at the MSD box electronically instead of moving the trigger around physically; reliability (because there are fewer components to fail).

Whether for motorcycle use or watercraft use, each MSD Digital Ignition is optimized for the particular vehicle. Obviously, a full technical explanation of correct ignition timing for each individual engine would take up too much room here. A broad overview of how to arrive at a timing curve is shown in the guide below.

Factor	Advance For	Retard For
Cylinder Pressure	Low	High
Engine RPM	Low	High
Energy of Ignition	Low	High
Fuel Octane	High	Low
Mixture (Fuel/Air)	Rich	Lean
Temperature	Cool	Hot
Combustion Turbulence	Low	High
Load	Light	Heavy

General Tuning Tips:

• You need to have all systems operating properly before you can fine tune your ignition system. Here are a few tuning tips for watercraft and motorcycles.
• Reading spark plugs is an important element of tuning. Take a good look at the insulator's ceramic coloring.
• A good light tan/gray color is perfect.
• If the plug is black with wet or dry deposits, it's usually a fouling problem. Heavy dry deposits might indicate too rich a carburetor(s), too cold a plug heat range, low compression, timing is retarded too far, or the gap is too big.
• If the deposits are wet, it could be due to a blown head gasket, bad rings or valvetrain problems, or too rich a carb setting.
• Silver specs, black specs, melting, or breakage at the firing tip on the plug is a sign of detonation.
• A white or real light plug color could possibly mean the carb(s) is too lean.
• Spark plug color is only accurate when checked after a high speed run, engine turned off at max rpm, and craft glided in with engine still off. No idling allowed!
• Each cylinder should be fine tuned as a separate motor/pipe/carb combination. Not all carb screws on multiple carb set ups will necessarily be adjusted the same - or jets necessarily the same size.

In most cases, it is usually due to a bad ground or no ground at all. Check all connections. Here are a few things you could check: make sure the ground wire is securely attached; that there is no paint under the ground wire; the connectors have good secure connections; there are no breaks in the wires; the battery is fully charged. Check for a bad on/off switch to the ignition box. You could have a bad coil, and switching it out for a coil that you know is good is the fastest way to determine whether a coil is the culprit. Perhaps you have a bad triggering device. Check it by removing the spark plugs (leaving the spark plug wires on), and grounding them to the engine. Next: clip the two green trigger wires coming out of the engine, and repeatedly touch the 2 wires going to the ignition box together. Make sure the power to your ignition is on. You should get a spark, or the L.E.D. (if equipped on your MSD box) should light. If you get a spark, then the trigger is bad. If the L.E.D. light turns on and there is no spark - then either you have a bad coil, a bad spark plug wire(s), or a bad spark plug(s).

A rev limiter does just what its name implies: it limits the revolution speed of the engine. Why is this important? If you have the throttle wide open on a watercraft and it comes out of the water, there is no load on the engine. The engine will dangerously zoom up in speed past its intended design and physical limits, possibly destroying itself. On a motorcycle if you have the throttle wide open and miss a shift, the same thing happens: a rapid increase in rpm's, possibly destroying parts. A rev limiter is placed in the electronic circuitry that prevents the engine from over-reving. At a pre-set rpm - say 7,000 rpm - the rev limiter engages. Once the engine reaches 7,000 rpm, it interrupts the signal to the coil, alternating on/off, slowing the firing sequence, and preventing the engine from rapidly shooting up in rpms. Factory rev-limiters are generally set at low rpm levels. If you have modified your engine you may not notice any performance gains due to the stock rev limiter's low rpm limit, which is why you would use a MSD Rev Limiter. With our units you can set the point, where you want the rev limiter to limit the engine's rpm.

With a MSD Ignition you can run a wider spark plug gap than you would be able to with a stock ignition. The MSD Ignition has a higher voltage output and can jump the spark plug gap easier. As an example, if you normally would run a .028 inch gap on your spark plug with a stock ignition, you could run a .032-.034 inch gap with a MSD Ignition. There are variables that will affect the gap size: the higher the compression - the smaller the gap; the hotter the output of the ignition - the larger the gap, etc.

Water is injected into the expansion chamber at specific rpm levels, this alters the sonic wave in the pipe. The water molecules directly affect the sonic wave properties, modifying back pressure deflection. You want the water to be injected at low to mid range rpms, and to be tapered off before your engine enters your upper rpm levels (leaving enough water to prevent any rubber couplers from melting). At 3,000 rpm the MSD Pulse Width Modulated (PWM) Switch turns on the water, by gently pulsing it on and off, then (at a rpm you preset) it will flow a steady stream of water. At a user preset rpm, the water starts pulsating on & off again, as the rpm rise, the volume of water decreases until the shutoff point is reached. There is no abrupt changes in power with the MSD PWM Switch...as though you are hitting a pipes' powerband. With the water gently pulsing on and off, instead of suddenly on and then suddenly off you avoid the unwanted pipe "power band" effect.

The primary benefits are low and mid range power increases. To also gain top end performance you could restrict the water flow in your pipe's stock cooling system, and use the MSD PWM switch to not only tune the pipe, but cool it at the same time. This is tricky because if you restrict the stock water cooling too much, you could melt the rubber couplers.

RF Noise stands for Radio Frequency noise. It is generated by spark plugs when they spark, and on motorcycles by points. RF noise causes CD ignitions to run erratically if they aren't shielded. A good way to lower RF noise is to use a good set of RF suppression spark plug wires - like MSD's 8.5 mm Super Conductor Wire or our 8mm Heli-Core wire. The Super Conductor uses a special winding procedure with a ferro magnetic impregnated center core that is an effective RF suppression spark plug wire. In addition to using good spark plug wires, make sure that all grounds are good and clean. If you still have RF problems, shielding the ignition or moving it away from the RF source helps reduce interference.

Easier starts, more horsepower, better throttle response are the expected results from a MSD capacitive discharge ignition - whether it's an analog or digital system.

With the multiple spark discharge of a MSD ignition, it is finally possible to completely ignite the air/fuel mixture in the cylinder - giving you more horsepower. In a 2-stroke engine this is important. When you suddenly give the engine "the gas" after idling, the engine will bog down. This is the result of a weak stock ignition trying to burn off the excess fuel that has built up in the cylinder. The stock ignition's weak spark can't do the job. A MSD ignition has a hotter spark to start with, and along with the multiple spark discharge, a MSD ignition will thoroughly ignite the air/fuel mixture.

Checking for spark output of your MSD is easy. Following is a simple procedure for testing your MSD for spark.

• Turn the ignition switch “OFF”.
• Remove the coil wire from the distributor cap and place it 1/2” from ground. DO NOT CRANK OVER THE ENGINE. When you continue with this test, a high voltage spark will jump this 1/2” gap so make sure there is no fuel or flammable mixtures near the plug wire end.
• If triggering with the Magnetic Pickup (Green and Violet):
  • Disconnect the magnetic trigger wires from the MSD. Turn the Ignition Switch “On”. DO NOT CRANK OVER THE ENGINE.
  • Use a paper clip or jumper wire to short the Green and Violet wires going to the MSD together several times. A spark should jump the gap every time the wires are shorted.
• If triggering with the White wire (points/amplifier):
  • Disconnect the White wire of the MSD from the distributor trigger or ignition amplifier. Turn the Ignition Switch “On”. DO NOT CRANK OVER THE ENGINE.
  • Tap the White MSD wire to ground several times. A spark should jump the gap as you do this.
• If there is no spark, substitute another ignition coil and repeat the test. If there is now spark, the coil is at fault. If there is still no spark it is possible that the MSD Ignition needs to be serviced. If the warranty period is over, MSD offers repairs at nominal fees. For more information on repair services, contact our Customer Support Department at (915) 855-7123 or [email protected]

• A high rpm miss when the engine is under load?
• An rpm limiter that seems to activate at the wrong rpm?
• Erratic operation of electronic devices/ECUs?
• A tachometer needle that seems to “bounce”?

All of the above can be caused by Electro Magnetic Interference (EMI) generated by the ignition system. Specifically through the coil and spark plug wires. The ignition system is a miniature power station and the spark plug wires are its transmission lines. The wires (in particular, “solid core” wires) can broadcast EMI that seeps into electronics and causes erratic behavior.

To combat EMI you need to run a set of helically wound spark plug wires such as MSD’s Heli-Core or 8.5mm Super Conductor Wires. Having the conductor wound around a special center core produces a “choke” that holds EMI inside the wire. Solid core wires on the other hand, have no suppression capabilities and should not be used with an MSD Ignition. MSD’s Super Conductor Wires have extremely low resistance (less than 50 ohms per foot), yet are designed to suppress EMI like a high resistance wire.

Other steps to avoid EMI problems include routing your coil’s primary wires away from other plug wires. The magnetic pickup harness coming from the distributor or crank trigger should be routed away from other wires and is a good idea to have it mounted along a metal surface that will act as a ground plain. MSD also offers a six feet long shielded mag pickup cable, PN 8862, that can be used if you are having problems with EMI interfering with other electronics on your vehicle.

MSD's Tach Adapters are solutions to two problems that may occur in a few applications after installing an MSD Ignition. They will modify the tach signal of the MSD so tachs that have trouble picking up the MSD’s signal and on select import vehicles with fuel injection systems, they will boost the signal so the ECU can trigger the EFI.

Some tachometers, original equipment and aftermarket, may have trouble reading the MSD’s tach signal causing erratic readings or just not working. An MSD Tach Adapter modifies the tach signal so these tachometers can read them correctly. MSD lists different tachs and applications that may require an Adapter in our catalog and the Ignition Control Instructions.

Some import vehicles may experience a no run situation after installing an MSD. This is because some systems use the same trigger source to operate the ignition and the fuel injection. When the MSD is installed this voltage signal becomes too low to accurately trigger the fuel injection. The PN 8910 Tach Adapter will usually remedy this problem. Ford Probes and Toyotas require a special Adapter that can be ordered directly from MSD.

If you experience any of these problems after installing your MSD, contact our Customer Support Department for more information on your application.

MSD does not have a module to replace the breaker points system in your stock distributor, however an MSD Ignition Control will work great with a points trigger ignition. In fact, if you replace the points when you install your MSD, you’ll probably won’t have to replace or adjust them for years!

The MSD’s trigger wire connects directly to the breaker points wire so when the points open, the MSD is triggered. Since the MSD’s capacitor is responsible for sending the spark energy to the coil, the points are only used as a trigger reference signal. With this connection there is very little current crossing the points so the wear is nominal at best. Also, the MSD controls the dwell so the adjustment of the points is not that critical either. This setup works great with street cars and budget racers, but when you begin stepping up performance more and more, the need for a quality distributor comes into play.

MSD’s Pro-Billet Distributors are engineered to deliver precise trigger signals, provide accurate distribution of the sparks and are reliable. A magnetic pickup is used to trigger the ignition. Unlike points, this pickup is maintenance free and is capable of accurate trigger signals throughout 10,000 rpm.

The spark plug is the point in the ignition system where electrical energy is converted into heat, consequently, the larger the gap the greater the amount of heat available to light the air/fuel mixture. However, too large of gap combined with increased cylinder pressures can put excessive pressures on the initial voltage needed to ionize (cross) the gap. Finding the optimum plug gap for your application is best determined by experimentation because there are so many engine variables to consider.

An MSD Ignition Control has enough output power to consistently fire wider spark plug gaps on a performance engine. As a starting point, follow the engine builder or manufacturer’s recommendation for the plug gap. With that, you can experiment with increasing the gap until the best performance is found.

As a rule of thumb, it is recommended to increase the plug gap by .005” - .010” followed by testing and tuning. Keep in mind that larger spark plug gaps also place increasing demands on the secondary portion of the ignition system including the distributor cap and rotor, coil wire, and spark plug wires. They should all be in top condition and checked periodically during the race season. Remember that electricity takes the path of least resistance to a ground so if the gap is too large the spark may short to another point with less resistance.

In the last few years a lot of other “performance” ignition companies have cropped up and not surprisingly, their ignitions are all similar to an MSD. They’re capacitive discharge, multiple sparking designs with rev limiters and timing controls. MSD was the first ignition company to use capacitive discharge, multiple sparking technology. We were the first to offer rev limiters, billet distributors and crank triggers. We know what it takes to deliver ignition performance and reliability. These are things you only learn with experience and we have over 25 years of exclusive performance ignition experience.

MSD goes to great lengths to provide the best performing and most reliable ignition components available. Every ignition that leaves our building has undergone a battery of tests including a four hour burn-in. The complete MSD line features a one year warranty and we have an excellent core of engineers, technicians and support personnel at the races and available to answer your calls about ignition systems.

In short, MSD builds the best performing and most reliable ignition products available and we have the wins and records to back this up. When you’re reading through the magazines or walking through the pits at a race, look inside the winners’ cars to see what ignition they’re running; MSD Ignition.

Bonus Pointers:

• You don’t need a ballast resistor if you are using an MSD Ignition Control. If you are using a points system with a Blaster Coil a ballast resistor is required.
• You can run an MSD Ignition Control to a 16 volt battery source.
• Do not run solid core spark plug wires with an MSD Ignition.
• Yes, an MSD will install to a late model LT-1 Chevrolet engine.
• Route your magnetic pickup wires away from coil primary wires and plug wires.

Conventional CD ignitions supply one spark of intense energy but for a short duration (time). An MSD uses multiple sparking technology to take advantage of the quick rise time and power of a CD Ignition by producing a series of sparks. More sparks equal more heat in the combustion chamber resulting in complete combustion of the fuel mixture which produces more power. At lower rpm, there are many benefits to multiple sparks including a smooth idle, improved throttle response plus the spark series prevents fouling plugs or fuel loading up in the cylinder when air/fuel distribution is poor.

The multiple spark series of an MSD Ignition Control lasts for 20° of crankshaft rotation. At lower rpm, 1,000 rpm for example, there is plenty of time to fire the plug a number of times to ensure ignition of the fuel mixture. As rpm increases, the piston travels up on the compression stroke faster resulting in a shorter amount of time available to fire the plug so the number of sparks that occur decreases. By about 3,000-3,300 rpm, there is only enough time to fire the plug once. From about this rpm range on, an MSD ignition control delivers one intense, full power spark.

The biggest difference is that the majority of stock ignitions are inductive ignitions. Inductive ignition systems are used due to their simplicity and inexpensive production. For stock applications these ignitions are adequate, but when it comes to gaining performance, factory inductive ignitions fall short.

The primary weak link of a stock ignition is because the coil serves double duty. The coil must act as a step-up transformer to create a higher voltage spark, plus it needs to store this power until the ignition is triggered. As engine rpm increases there isn’t enough time to completely step-up the voltage before the ignition is triggered resulting in a weaker spark. This low voltage spark may not be enough to light the fuel mixture in the cylinder which will result in a misfire and loss of power.

ACD ignition, like an MSD 6 Series, is capable of producing full power sparks throughout the entire rpm range. It draws its energy directly from the battery where a custom wound transformer steps it up to over 460 volts. This voltage is then stored in a capacitor until the ignition is triggered. At this point, all of the voltage is dumped into the coil where it is transformed into even more voltage, anywhere from 30,000 - 45,000 volts depending on the coil, which is sent to the distributor and finally to the plugs.

The ability to produce high power sparks throughout the entire rpm range of your engine is why you need a CD ignition. The payoff is complete combustion of the fuel mixture which results in more power, increased throttle response, a smooth idle, quick starts, improved economy and reduced plug fouling.

All engines will benefit from a CD ignition but when you’re planning on engine modifications, the need for an MSD Ignition increases. In particular, if you’re planning these types of engine modifications, you should be installing a CD ignition:

• Improving air flow into the engine or richening the fuel mixture (rejetting or larger injectors)
• Adding a super/turbocharger or a nitrous oxide system
• Increasing the compression ratio and consistent high rpm operation

The battery is the fuel tank for the ignition system (magnetos excluded). When it’s empty there is no electrical power available for the ignition system to convert into heat at the plug gap. In long duration racing events such as circle track racing, an alternator is highly recommended. In drag racing, a charging system is not a complete necessity as long as you have a good battery and charge it in between each round. Also keep in mind that electric fuel and water pumps, fans and solenoids eat up a lot of current as well.

Race cars without charging systems must have a battery with a large enough capacity to power all the electrical parts. For example, an MSD 6 or 7 series ignition consumes approximately one amp per thousand rpm, so at 5,000 rpm the MSD alone is using five amps. An MSD is designed to produce full power sparks with a supply voltage of 10 volts, but if the supply drops below that, ignition output will suffer.

An MSD can be used with 16 volt batteries, but no performance gain will occur because the output power of the MSD is regulated. The advantage of a 16 volt battery is increased electrical capacity. For more information on battery requirements with an MSD, ask your MSD Customer Support Tech for our Battery Tech Bulletin.

There is no real way for our Techs to answer this question but they can point you in the right direction. It takes testing and tuning time to find the best curve that fits your application. Many variables affect the ignition timing curve such as compression, cam specs, intake system, fuel, exhaust, altitude, driving habits and so on. The chart on page 3 lists some factors that will help you determine what sort of timing curve you should work towards for your specific application.

MSD’s mechanical advance mechanism is accurate and easy to adjust so you can try different combinations with the supplied springs and stop bushings. We also offer a variety of electronic timing controls so engines with locked out timing or crank triggers can take advantage of altering the timing as rpm changes.

Note: When you are testing different curves, listen for detonation (spark knock) which is a sign of over-advanced timing.