Mallory Ignition ACCEL Ignition 35496 User Manual

Page 5

ACCEL IGNITION

www.accel-ignition.com

RECOMMENDED TIMING SETTINGS

Street and race advance curve families are shown in Figures 6 and

7. Each family has minimum and maximum curves. The advance slope

switch allows you to run an advance curve in between these minimum and

maximum curves. Advance slope switch setting zero corresponds to the

minimum advance curve. Switch setting 9 corresponds to the maximum

advance curve. Higher switch settings result in a more aggressive curve.

Tuning a particular engine setup always requires some trial and error

experimentation, but maximum power is usually obtained by using the high-

est advance setting possible without audible spark knock. Some recom-

mended starting points are given below:

For stock engines run on normal pump gas (87-89 octane), use the street

advance curves and advance slope setting 5.

For stock or mildly modified engines run on 92 or higher octane gas, use

the street advance curves and advance slope setting 7.

For high compression engines, use the race advance curves and

advance slope setting 2.

You can adjust the initial timing by rotating the ACCEL module relative to

the gear housing (clockwise rotation increases initial timing).

If you experience spark knock only at low RPM, you can try reducing the

initial timing while maintaining an aggressive advance slope for maximum

power at high RPM by increasing the advance slope switch setting. If spark

knock is a problem at high RPM, decrease the advance slope switch setting.

Note that the wide-open throttle (WOT) curves are active unless the

VOES input is grounded. During idle and cruise, the VOES input is grounded

(green VOES LED illuminated) and the low manifold pressure (MAP) curves

are active.

RPM LIMITER SETTING

You can set the RPM limit from 3,000 to 9,900 RPM in 100 RPM incre-

ments by means of two rotary switches. The RPM limit is X100 switch set-

ting (i.e. 57 = 5,700 RPM). Inadvertent settings below 3,000 RPM are ignored

and result in a 3,000 RPM limit.

The Model 35496 uses a newly developed RPM limiting algorithm that

has been highly optimized for odd firing V twin engines. When the engine is

held against the RPM limit, cylinder firing is always paired. This eliminates

a torque couple and results in very smooth operation compared to random

or sequence type RPM limiters.

Set a safe RPM limit that is appropriate for your engine. Most Evolution®

engines with OE valvetrain components should not be run over 5,700 RPM.

STATIC TIMING PROCEDURE

1. Timing marks are located on the flywheel and may be viewed by

unscrewing the inspection hole plug. Most engines will have both TDC

and advance timing marks for the front cylinder as shown in Figure 8. If

you are not sure, refer to your shop manual. You can also identify the

TDC mark by removing the spark plugs and rotating the crankshaft (turn

rear wheel in high gear) until the front piston comes up on TDC.

2. For static timing, you must rotate the crankshaft so that the front piston

is at TDC on the compression stroke. Remove spark plugs and rotate

crankshaft. If you place your thumb over the spark plug hole, you

will feel pressure as the piston comes up on the compression stroke.

Continue rotating the crankshaft until the TDC mark is precisely centered

in the inspection hole.

3. Ground the spark plug cables to avoid a shock hazard. You can use small

jumper wires with alligator clips for this purpose.

4. Turn on the ignition switch. The red LED is used as a timing indicator.

Note that the LED does not immediately illuminate when power is first

turned on. Rotate the ignition unit back and forth until the red LED illumi-

nates. Then slowly rotate the unit clockwise until the LED goes out. Note

that the LED goes out at TDC.

5. Tighten the standoffs to secure the unit. Turn off the ignition switch and

reinstall the spark plugs.

PRECISE TIMING PROCEDURE

1. Use a standard timing light. Note that most dial-back type timing lights

will not work correctly with dual fire applications. If you have a dial-back

timing light, set the dial-back to zero. Do not enable multi-spark while

setting timing.

2. The precise timing procedure is based on using the 35° BTDC timing

mark and race maximum advance curve with VOES grounded that

reaches 35° BTDC around 2,000 RPM (refer to Figure 7). To use this pro-

cedure, you must have a VOES switch connected. If a VOES switch is not

used, you must ground the purple/white wire while setting the timing.

3. Set mode switch to 4 for dual fire or 6 for single fire. Set advance slope

switch to 9. Connect the timing light pickup to the front cylinder spark

plug cable. Loosen standoffs securing the ignition unit. Run the engine

at a steady speed just over 2,000 RPM. Rotate the ignition to center the

35° BTDC timing mark in the inspection hole. Tighten standoffs and verify

that the timing has not changed. When done, change mode and advance

slope switches back to desired values.

Figure 6 - Street Advance Curves

1000

2000

3000

4000

5000

6000

7000

ENGINE RPM

ADV

ANCE

(DE

)

MAX ADVANCE AT WIDE OPEN THROTTLE

MIN ADVANCE AT WIDE OPEN THROTTLE

MAX ADVANCE WITH VOES GROUNDED

MIN ADVANCE WITH VOES GROUNDED