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Author Topic: Initial Spark Timing- where do YOU have it?  (Read 1445 times)

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Offline BlackMax

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Initial Spark Timing- where do YOU have it?
« on: July 23, 2009, 06:42:05 AM »
Set at the "F" mark (5 degrees before tdc I'm pretty sure) or do you have it set more/less advanced....?   Just curious where everyone has it.
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cycleman

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Re: Initial Spark Timing- where do YOU have it?
« Reply #1 on: July 23, 2009, 06:52:44 AM »
Your correct, stock setting at the F mark. That's what I use.
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Offline mystic_1

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Re: Initial Spark Timing- where do YOU have it?
« Reply #2 on: July 23, 2009, 05:28:36 PM »
I've always set mine right on the F.

mystic_1
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Offline Zaipai

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Re: Initial Spark Timing- where do YOU have it?
« Reply #3 on: July 23, 2009, 05:30:56 PM »
Quote from: mystic_1 on July 23, 2009, 05:28:36 PM
I've always set mine right on the F.

mystic_1

Same here.. (75 CB550F)
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Offline lordmoonpie

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Re: Initial Spark Timing- where do YOU have it?
« Reply #4 on: July 24, 2009, 08:05:23 AM »
Mine's set at the parallel hair marks to the right of the F mark - about 38 degrees advance but then I'm running a boyer ignition in a very non-stock motor...
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Offline BlackMax

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Re: Initial Spark Timing- where do YOU have it?
« Reply #5 on: July 24, 2009, 09:27:46 AM »
Quote from: lordmoonpie on July 24, 2009, 08:05:23 AM
Mine's set at the parallel hair marks to the right of the F mark - about 38 degrees advance but then I'm running a boyer ignition in a very non-stock motor...

I show the parallel ticks to be more like 22 BTDC.  I show the "F" tick to be 5 degrees BTDC. 

Am I wrong? 
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Offline IHWillys

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Re: Initial Spark Timing- where do YOU have it?
« Reply #6 on: July 24, 2009, 09:59:29 AM »
How about where on the case mark do you set it?  I set it on the F mark but there is some variation there.  Set the F mark to the leading edge, trailing edge or the center of the case mark, etc.  I did not get out the wheel to see how much degree difference is there.  A few degrees of advance/retard can slightly change operating temps.  Do the middle cylinders run a bit hotter than the outer cylinders?  Small timing difference between them can help/hurt in that regard.  It also can affect ease of starting.  Advancing the ignition timing generally will decrease ease of starting.  How much depends, but it can be factor.

I have mine timed right now on the F mark lined up with the trailing edge of the case mark.  This puts it on the retarded side.  This is a resurrected, close-to-stock CB550F (came with a "new" rear tire made in 1994 on it) which I am likely to sell soon so I set it up conservatively.  I'd rather have maximum friendlyness in starting and low-end power vs tweaking the initial to push the whole curve up for possibly better high-rpm performance on this one.  Changing the curve would open up more flexibility but we're just talking about initial timing here.

Ken
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Offline Flying J

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Re: Initial Spark Timing- where do YOU have it?
« Reply #7 on: July 24, 2009, 10:42:00 AM »
what about what honda man says.
Quote
Advance the timing 2 degrees static, but cut off one turn from the springs on the advancer and reshape the end of the next coil so the springs will fit back onto the advancer mounts. This slows the advance curve about 5%-8%, depending on the year of your bike.
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Offline IHWillys

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Re: Initial Spark Timing- where do YOU have it?
« Reply #8 on: July 24, 2009, 11:34:04 AM »
Quote from: ffjmoore on July 24, 2009, 10:42:00 AM
what about what honda man says.
...

Well, the man speaks from mucho experience so I expect it's good advice.  One question would be what is the context of the advice?  Best peak power on an otherwise stock setup?  Best mid-range ridability on a stocker?  Slightly modified?   Best economy?  etc...  Tuning is replete with complimentary actions and compromises.

Ken
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Offline Gordon

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Re: Initial Spark Timing- where do YOU have it?
« Reply #9 on: July 24, 2009, 01:37:05 PM »
Quote from: ffjmoore on July 24, 2009, 10:42:00 AM
what about what honda man says.
Quote
Advance the timing 2 degrees static, but cut off one turn from the springs on the advancer and reshape the end of the next coil so the springs will fit back onto the advancer mounts. This slows the advance curve about 5%-8%, depending on the year of your bike.

I did this Hondaman mod to my 550 a few weeks ago.  Along with opening up the air intake a bit it really helped get rid of the flat spot in the mid rpm range. 
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Offline Jim F

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Re: Initial Spark Timing- where do YOU have it?
« Reply #10 on: July 24, 2009, 04:36:41 PM »
36 degrees BTDC on mine
with an ARD MAG
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