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540 xdi ignition


Well-known member
My sons boat has the xdi on a O360. I have been curious as well. Does yours have 4 dials, with no digital readout?

Slidin Gator

Well-known member
I have a lycoming 540 with xdi ignition system. Curious what’s the optimum settings.

Have you discussed with whoever installed it? If not you should call Abner at Elite Airboats 863-261-2340, they are an installer and distributor of that setup.

Is the picture below the unit?
XDi Ignition - Electromotive

If so the 4 dials each control the following:
• Initial advance 0-30°
• 3k rpm advance 0-30°
• 8k rpm advance -12° to 12°
• Variable rev limiter 4k-15k or off

I don't know what the optimum settings are for your engine, but the standard (i.e. safe) Lycoming settings are 25 deg BTDC. I would set the first 3 to 25 and the rev limiter to off. Otherwise talk to the builder/installer/Abner for advice.


Slidin Gator

Well-known member
A word of advice. The following is listed in the XDI manual. Basically, without knowing that your timing trigger occurs at 0 Deg BTDC, the above advice might not be correct. From the manual:


5.1 Overview of Ignition Timing
Perhaps the most important step in tuning an engine is establishing the required ignition advance. An engine with too much timing will detonate, regardless of how much fuel is thrown at it. An engine with too little timing will perform poorly, and overheat the exhaust in short order. We are looking for the happy medium here. Keep in mind that the timing settings are solely dependent on the crank trigger installation angle. If the crank sensor is aligned with the 13th tooth of the trigger wheel when the engine is at TDC #1, the engine timing will be mechanically advanced by two teeth (12 degrees). When this occurs, the timing values on the knobs will be 12 degrees LESS THAN the actual engine timing. If the crank sensor is aligned with the 10th tooth at TDC#1, the timing will be mechanically retarded by one tooth (6 degrees). When this happens, the timing values on the knobs will be 6 degrees MORE than the actual engine timing. Always confirm your knob timing values with a timing light! Remember that dial-type timing lights will not read correctly with the XDI due to the waste-spark. To avoid potential engine damage, it is best to check engine timing with a timing light when first starting the tuning process.