Español   TACHOMETER FOR ROTAX ENGINES with Bosh Ignition System 57mm Diameter The IM-106 instruments have been designed especially to measure the RPM in Rotax® engines with Bosh Ignition System.  The IM-106 is available in 57 mm diameter.  The IM-106 not need external power suply. The minimum instrumentation requirements  for the BRP_ROTAX® two stroke engines include a gauge for continuous RPM monitorization. The AVIASPORT   IM 106 tachometer is specially designed to be connected to the BOSCH magneto generator mounted in the old ROTAX UL engines , but it can also be connected to other similar generators.  Unlike most of the existing tachometers, this one is connected only to the AC output ( lighting coil ) of the engine. This avoids the risk of stopping the engine if a failure in the instrument or connecting wires causes a short-circuit. It takes its power supply from the AC output, making connection to DC power unnecessary.   Technical data Case Plastic Weight 220g Suitable for Bosh ignition unit Power Supply Not need external power suply Scale 0..8000 rpm Subdivision scale 250 rpm each Max. Deviation 2% Dimensions See sketch Calibration Calibrated by the manufacturer prior to shipment. Wire Connections The two generator coils come joined in parallel. If using a rectifier-regulator, do not connect the tachometer in parallel with it. In this case it is necessary to separate the yellow wires from the green ones, leaving 7 wires coming out from the engine. The 2 black wires go to the kill switch, the brown wire is engine ground (usually no connected). The tachometer wires do not have polarity. WITH RECTIFIER-REGULATOR WITHOUT RECTIFIER-REGULATOR Dimensions