sportster timing marks

26390 Views 15 Replies 6 Participants Last post by FrankieD, Oct 11, 2012

vik morgan

Discussion Starter · Feb 1, 2012

Unlike big twins, sporty's do not seem to have very detailed timing marks. I have a '95 and I am guessing that the single dot indicates 30 drg BTDC? Is there a mark for TDC? and to verify the timing on the rear cylinder I would guess to pull the ingnition, mount a timing wheel and mark the flywheel at 75 BTDC at the front cylinder?

1 - 16 of 16 Posts

DarkGoat

· #2 · Feb 2, 2012

single dot is 35 degrees btdc(domestic timing) double dot is 20 degrees btdc (international timing) line is top dead center front cylinder. All 96 and later ignition modules are timed at 20degrees. If you are using stock ignition you do not need to verify rear cylinder timing. Timing is all set to front cylinder.

Threadkiller

· #3 · Feb 2, 2012

^Acccurate information^ However most, if not all aftermarket ignition systems generally use 35*BTDC as their 'home' timing mark. When using one of these systems setting up the static timing is usually sufficient for proper combustion. TK.

DarkGoat

· #4 · Feb 2, 2012

Keep in mind that 35 or 20 degrees is a base line and your machine due to its state of tune may require advancing or retarding to find optimal running.

vik morgan

Discussion Starter · #5 · Feb 2, 2012 (Edited)

Thanks for the info. Its got a Daytona Twin Tec ignition and according to their instructions, they static time off of TDC. Once static timed I'd like to verify that the front and rear are hitting at the same mark from their respective TDC.
With the current state of tune, or lack-there-of, I am trying to get everything back to a common starting point which means to me checking everything- timing at the front and rear cylinders, compression, cam timing, blah, blah.
The rear is actually my concern as it seems very weak and there is no carbon build up in the port. And, whether or not related, the bike also has some pretty bad reversion and likes throwing fuel out the wrong way.

DarkGoat

· #6 · Feb 2, 2012

vik morgan said:
Thanks for the info. Its got a Daytona Twin Tec ignition and according to their instructions, they static time off of TDC. Once static timed I'd like to verify that the front and rear are hitting at the same mark from their respective TDC.
With the current state of tune, or lack-there-of, I am trying to get everything back to a common starting point which means to me checking everything- timing at the front and rear cylinders, compression, cam timing, blah, blah.
The rear is actually my concern as it seems very weak and there is no carbon build up in the port. And, whether or not related, the bike also has some pretty bad reversion and likes throwing fuel out the wrong way.

top dead center on the compression stroke of the front cylinder. If you time it a TDC overlap stroke it will not run

sporty257

· #7 · Oct 10, 2012

I am installing a new fire ball hi-4 ignition from crane cams onto my 2002 xl1200c. i am having a problem. I aligned the timing mark in the window (the TDC line) turned on the ignition, loosened the mounting screws, and proceeded to turn the module clock wise till the led light turned off. The problem is the light never turned off. i went full left and right and got nothing the light stays on. The bike starts but is running on the front cylinder only. I know this because it is only blowing cold air out of the rear exhaust while the front one is blowing hot air. What am i doing wrong?

G

· #8 · Oct 10, 2012

MAKE SURE THAT YOU ARE ON THE POWER STROKE and the rotor cup is index into the cam...

100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

DarkGoat

· #9 · Oct 10, 2012

I have had trouble getting static lights to turn off as well try cycling the igniton. Dragstews is right of course...must be on compression stroke. Take a plug out and feel for air being pushed out, front cylinder.

DarkGoat

· #10 · Oct 10, 2012

are you using it as a single fire or dual fire set up?

sporty257

· #11 · Oct 10, 2012

dual fire

DarkGoat

· #12 · Oct 10, 2012

dual fire and not firing on one cylinder, check the fundimentals...spark plugs, wires.

sporty257

· #13 · Oct 10, 2012

The rear plug fires when when it is out of the bike. I pulled it out of the cylinder and grounded it against the cylinder and cranked the bike and it sparks. But when the bike is running it just blows cold air out the pipe, I can grab and hold the pipe and it never gets warm. Only on the rear cylinder.

DarkGoat

· #14 · Oct 10, 2012

cylinder pressure can kill spark, the plug is still suspect. Any other work done to this machine?

sporty257

· #15 · Oct 10, 2012

No completly stock except for a set of drag pipes. I'm running a new oem coil and wires

FrankieD

· #16 · Oct 11, 2012 (Edited by Moderator)

I remember putting the dyna ignition in my '57xl and I was told to hook up the cylinders reversed.I was told the distributer rotates reversed to a big twin and the kit was only made for the big twin not sportsters.

Intro Please.....Will break the Ice better....

1 - 16 of 16 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.