The size of the spark generated by the spark plug and the ignition timing are important factors that affect the condition of the fuel engine. The OEM ignition system also provides the necessary and sufficient performance, but by installing high-performance parts, the performance can be greatly improved. The SPII Full Power Kit, which is designed and manufactured in-house by AS UOTANI, has been used by many users as an ignition system part that shows a difference.
SPII pursues high performance theoretically, not by feeling or atmosphere.
The combination of SPII high power ignition coil that produces a large spark and SPII control unit that can flow a large current realizes AS UOTANI's unique ignition system tuning. The rotor and pickup base, which create the ignition signal, are specially designed for each model and can be installed by bolt-on.
The principle of a fuel engine is that the electric spark from the spark plug ignites the air mixture before top dead center, and the expansion pressure from the explosive expansion in the combustion chamber pushes the piston down to produce power. There are a number of factors involved in tuning an engine, such as carburetors, injection, exhaust systems, chambers, camshafts, etc. Replacing these factors have no effect if the spark plugs does not produce a spark in the end.
There are several ways to improve the performance of the ignition system, such as replacing high-performance plugs and high-tension cords, but AS UOTANI is manufacturing its own parts to review the ignition system further upstream. To maximize the potential of the engine, the AS UOTANI has developed 2 products: the SPII Power Coil Kit and the SPII Full Power Kit. The former is the SPII High Power Ignition Coil, which can generate higher voltage and current than the OEM ignition coil, and the latter is a combination of the SPII High Power Ignition Coil and the SPII Control Unit (igniter) developed specifically for the motorcycle model.
The igniter and ignition coil are installed as a set on any motorcycle with transistor ignition. Both have been developed by motorcycle manufacturers and parts suppliers and have the necessary performance. However, as mass-produced motorcycles, they are subject to the same manufacturing cost barriers as other parts such as brakes and suspension. It doesn't mean that the OEM brakes can't stop, and it doesn't mean that the OEM suspension can't absorb shocks from the road. However, by installing external high performance parts, you can feel the performance surpassing the OEM.
The same is true for ignition system parts. The OEM parts can produce the necessary spark for accurate ignition timing, but there is room for further improvement in performance by spending more money. This growth potential is the reason why AS UOTANI created the SPII series.
One of the features of the AS UOTANI is its thorough and logical approach to development. In order to generate a bigger spark at the spark plug, the voltage and current generated by the ignition coil must be increased. To achieve this, the SPII High Power Ignition Coil selects a coil with higher performance than the OEM parts, and the voltage flowing to the spark plug is approximately 40,000 volts. Since the STD voltage is 20,000 to 30,000 volts, this is about twice the voltage. Similarly, the discharge current is 1.5 to 2 times higher than STD, and the discharge time is also 2 to 3 times longer than STD. The OEM ignition coil can provide the necessary spark power for a STD engine, but the SPII high power ignition coil is designed to increase the performance by adding more power.
If the ignition coil can produce a strong spark due to its high performance, then the OEM igniter is not sufficient. The ability of the ignition coil is affected by the winding ratio and resistance of the 2 sets of coils. The primary coil of the SPII High Power Ignition Coil has a lower resistance value than the OEM coil, which makes it easier for high current to flow. This allows the igniter to intermittently draw more current, but unfortunately, the OEM igniter does not have the capacity to do so. Specifically, there is not enough capacity in the transistor inside the igniter that interrupts the current flowing to the ignition coil.
For this reason, AS UOTANI has developed the SPII control unit using a high-capacity transistor that can drive the SPII high-power ignition coil with plenty of room to spare. By using a control unit capable of carrying a large current, the current flowing through the ignition coil is intermittent, and the high voltage generated during the intermittent flow is applied to the primary coil to obtain a larger secondary voltage and current. This is the outline of the high performance ignition system by AS UOTANI, and it is reasonable from every angle.
If you think of it as the same logic as famous brand suspensions and brakes, it will make sense that the pursuit of ideal performance will cost more than OEM parts. For discontinued motorcycles with point ignition, the SPII Full Power Kit is also more than just a tuning parts.
- Point 1: As with brakes and suspensions, there are products with ignition systems that offer performance superior to OEM parts.
- Point 2: AS UOTANI's SPII series is developed by theoretically constructing a mechanism to generate a strong ignition spark.
Point ignition motorcycles as well as transistor ignition motorcycles can experience value beyond price.
This custom model features a Kawasaki GPZ400 chassis with a Zephyr X engine. When installing the SPII Full Power Kit on such a motorcycle, choose the kit for the Zephyr X because the ignition characteristics depend on the engine.
On the left is the GPZ400 OEM rotor and pickup, and on the right is the SPII control unit parts for the Zephyr X. The OEM GPZ400 with transistor ignition has pickups for 1, 4 and 2, 3 plugs facing each other, but the SPII has only 1 pickup because it uses digital circuit to detect the ignition status. The waveform generated when passing the pickup differs between the side with one long projection and the side with the long and short projections next to each other, and the current to the ignition coil is cut off by judging the number 1 and 4 from the number 2 and 3 based on the difference.
The contactless, full-transistor ignition system is maintenance free, with nothing to do except replacing the spark plugs. However, points ignition, which was the norm until the 1970s, requires regular maintenance, such as adjusting the gap due to wear of the points contacts and adjusting the ignition timing. Also, since the points are physically opened and closed, the ignition timing becomes unstable depending on the engine speed. This is why transistor ignition has replaced it.
The OEM ignition system of many popular models in the discontinued motorcycle world, such as the Kawasaki Z1/Z2 series and the Honda CB750 Four series, is a point system. For these models, the SPII Full Power Kit is a product that allows for both tuning and repair. The reason why racing carburetors are still favored is because a new racing carburetor is more stable and smooth from idling than an OEM carburetor that is not in good shape due to wear and tear on various parts.
There are some owners who think that point ignition has more of a unique characteristic than digital ignition, but motorcycles equipped with the SPII Full Power Kit, which generates powerful sparks one shot at a time even at idling rpm, have an excellent sense of stability at low rpm. Also, even if the carburetor setting is slightly off, the spark plug has a large spark to trigger a strong combustion.
The effect on older point ignition motorcycles is clear, but it is also a strong ally for older transistor ignition motorcycles. The 6-cylinder models such as the Honda CBX and Kawasaki KZ1300 have many enthusiasts, but new OEM igniters are not available. Even if it is hard to break, it is an electrical component and there is no way to fix it if the plug stops firing. AS UOTANI has also developed the SPII Full Power Kit for these models, so owners can continue to ride with ease.
- Point 1: By installing the SPII Full Power Kit on the point ignition, which is inevitably subject to performance degradation over time, it is possible to achieve both high performance and maintenance-free operation.
- Point 2: The SPII control unit may be able to revive transistor-ignition motorcycles that have become immobile due to lack of spare parts.
Prepared for tuning based on analysis of the OEM ignition curve.
The pickup becomes a single piece, but since the pickup base is OEM parts, installation is completely bolt-on.
The designation of 1.3mm spark plug gap after the SPII full power kit is installed shows the pride in the strength of the spark and the size of the spark. Normally, the gap of STD plugs is 0.7 to 0.8 mm, and even with the wide gap designation, it is 1.1 mm. If the gap is wider than this, the OEM ignition unit will not be able to send out sparks, leading to fire loss. Even with an ultra wide gap of 1.3mm, the spark can be sent out at high voltage, so the initial spark is large and the mixture can be ignited without fail.
One of the reasons why the SPII full power kit is so trusted is that it can be developed specifically for each motorcycle model and can be installed as a bolt-on. Whether the OEM system is transistor ignition or point ignition, when motorcycle manufacturers develop the ignition system, they set the ignition curve that is suitable for the OEM engine. Specifically, the ignition curve starts from the ignition timing at idling, the engine speed at which the ignition timing advances, and the maximum advance angle value.
Such settings are not necessary when only the ignition coil is replaced, but for the SPII Full Power Kit, the OEM igniter is replaced with the SPII control unit, so the ignition curve must be programmed anew.
In developing the SPII control unit for each model, AS UOTANI analyzed the ignition curve of the OEM igniter for all models and set multiple ignition curves based on the results. Therefore, even if the SPII Full Power Kit is installed on the STD state of everything from the engine itself to the intake and exhaust systems, you will be able to enjoy the benefits of only the strength of the powerful spark without any discomfort.
On top of that, multiple ignition maps are programmed to select the best ignition state according to the engine tuning and riding style, and the rider can easily select the map by simply switching the mode switch.
Good mixture, good compression, and good spark are the 3 most important elements for a fuel engine. Compared to the first 2, spark is often neglected, but enhancing it can have a definite payoff. AS UOTANI's SPII is a high performance parts that maximizes the potential of both OEM and tuned engines.
- Point 1: The ignition curve of the SPII control unit is set based on the analysis of the OEM curve of the motorcycle model to which it is installed, so it is compatible with engines with OEM specifications.
- Point 2: Multiple ignition timing settings that can be adjusted according to engine specifications and rider's riding style.
See HONDA Moto Index Page
See KAWASAKI Moto Index Page
See Accessories for HONDA CB750 Four (CB750K)
See Accessories for KAWASAKI GPZ400
See Accessories for KAWASAKI Z1300 (KZ1300)
