V-Twin Forum banner
1 - 2 of 2 Posts

Premium Member
8 Posts
Discussion Starter · #1 ·
I am hoping someone can give me some additional advice as to the best method of setting the Spark Advance on a newly installed SE MAP Ignition Module for my NEW engine build of 800 miles?

Here are my bikes components:

2002 Fatboy

113" HD Kit (with stroker)
SE Bigger Bore Pistons (10:5:1)
SE CNC Ported Heads
45 Mikuni, with Doherty Power Pacc breather
Doherty Power Vents and Mist Free
SE Big Bore Manifold
SE 260 cams w/support brackets
Adj Pushrods
Roller Rockers
V&H Long shots (no baffles)
SE MAP Ignition

I have my SE Adjustable Ignition currently configured like this:

Curve Setting = 3 (High Performance engines with up to 10:5:1 compression

Engine Speed = 6000 RPM limit

Spark Advance = +4

My question is this, Harley defaults the Spark Advance to 0 setting, and I have been increasing it by 1 degree increments until I hear a pinging sound and then I will back it off 1 degree. Since I am not using a Dyno, is this the best method for finding the correct SA setting, or is there a better way? I am currently sitting at +4 degrees advanced with no ping (Amoco 93 octane) and it runs great, though I have not tried the +5 or +6 setting. My concern is can I do any damage by continuing to advance the spark, it's maximum advance is +6 degrees.

I was also told that advancing the spark will create more heat in the engine and to be careful with that. I have a laser heat tester so where should I be checking the engine temp ( jug, exhaust, etc.) and what is the range my bike should be operating in. That goes for the oil temp as well, what range should that be?

Thanks a million for your help!!


Premium Member
1,389 Posts
you first need to get it on a dyno...just a cheap $75.00 pull to see where your AF numbers are. Remember its 1) fuel )2 timing 3) exhaust.
A richer motor will tolerate more timing... Get the af numbers correct ..then play with the initial and slopes to see what it likes.... but my guess is if your fuel is good and not too lean ... that cam has lots of duration and overlap which means lots of bleed off and lower cylinder pressures. On curve 3 which is 9 degrees total retard from stock with a less agressive climb..adding 4 degrees puts you at curve 2 -0- (minus five degrees from stock) but with a less agressive curve (than 2). I bet with a 3.37 gear it would like curve 2 at 0 initial.
I would be more worried about detonation with a 9.8:1 37g build or a 26g in a 95" bagger than with your combination.
I ran my 95" Dyna at 10.6:1, SE heads and forged pop ups, with tw8G cams, and a 44cv with 3.37 gears on curve 2 -0- initail. 94 sunoco . 108HP 104tQ with no pinging.
Get the fuel good and add timing till the power falls off...but I dont think you have anything to worry about where you are now.
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.