S&S Cycle EZFI-C - Manual (Page 4)

4
EZFI-C™ OPERATION
The EZFI-C system is simple to operate. A 10 position mode switch allows you to select which RPM and throttle range to tune. The 10 operating
modes are listed in Table 4. The display is turned off in Mode 0.
The Value LED displays the adjustment percentage for the selected range. The indicated number is the percent fuel being added (positive) or taken
away (negative) from the base pulse width. The small LED is lit when the adjustment is negative, which means the EZFI-C is leaning the mixture out
in that range.
The Up and Down buttons raise or lower the fuel adjustment for the selected operating range.
Advanced tuning of both front and rear fuel maps is possible when our EZTune software is used in conjunction with our S&S® Super Stock® diagnostic
cable. These are available separately.
Basic Tuning Tips
Now that you have EZFI-C installed and understand how to operate it, you are ready to tune. Here are some basic tips to make tuning with EZFI-C
faster and more productive.
Take Notes
Tuning while riding is not a safe practice. If the engine hesitates, surges, or doesn’t run right, make a mental note of which operating range it is
occurring in. Just keep tabs on the RPM, throttle position (cruising at part throttle or accelerating hard at wide open throttle?) and the behavior
(surging, sluggish response, missing, etc.) Then at a safe spot, pull over and write down your notes.
Warm Up The Engine Before Tuning
Starting your tuning session with a warm engine minimizes the amount of temperature compensation that the stock ECM might be adding in. It also
ensures repetitive results. If you tune the motorcycle with the engine cold, you will probably end up re-tuning it later when it’s warm.
If Possible, Measure What The Engine Is Doing
The fastest method of tuning requires wide band air fuel ratio (AFR) measurements. There are numerous stand-alone wideband systems available,
which can be operated while riding the motorcycle. Most tuning centers are equipped with wideband systems, which usually analyze the AFR
using a sensor inserted into the exhaust pipe. Either method will provide better data than “seat of the pants” interpretations of engine operation.
Knowledge of the AFR at various operating points allows you to dial in the precise fuel adjustments necessary to hit your target AFR.
Know Your Symptoms
Adding fuel does not solve all running problems. Many engine modifications will require a reduction in the amount of fuel at certain operating
points for optimal tuning. Don’t be afraid to take fuel away.
Coughing or surging usually indicate a lean condition. These conditions will require adding fuel to correct. Measuring your AFR with a wideband
system will give much better results than trying to diagnose the symptoms.
Tuning On Closed Loop Vehicles
Closed Loop vehicles require no special considerations with the EZFI-C.
Table 4 - Operating Ranges for Mode Switch Settings
Mode Switch Position Adjustment Range
0 None – display off
1 Wide open throttle 1250-2000 RPM 60-100% TPS
2 Wide open throttle 2000-2500 RPM 60-100% TPS
3 Wide open throttle 2500-3000 RPM 60-100% TPS
4 Wide open throttle 3000-4000 RPM 60-100% TPS
5 Wide open throttle 4000-5000 RPM 60-100% TPS
6 Wide open throttle 5000-6000 RPM 60-100% TPS
7 Wide open throttle above 6000 RPM 60-100% TPS
8 Entire operating range above 5000 RPM 0-60% TPS
9 Acceleration enrichment (0 = none, 10 = maximum)
Picture 2
Mode switch Up/down buttons
Negative LED Value LED