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static timing

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frankovy
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Joined: Sat Apr 16, 2005 2:19 pm

static timing

#1

Post by frankovy » Fri Aug 11, 2006 12:43 am

what am i doing wrong. cotten if your ever in toronto canada give me a call.

this is what i'm doing
#1 piston is on compression stroke
slash mark is forward of hole in engine case.
larger lobe on magneto shaft is centered on points 16thou gap on points.
magneto fully advanced.
won't start compression seems weak.



Cotten
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#2

Post by Cotten » Fri Aug 11, 2006 1:30 am

Frank!

I dream of getting out of state (once a year), much less across the border.

Did you determine the compression stroke by the front intake valve?

I seem to remember it was the small lobe that corresponds to the front cylinder, and the wide is the rear, on my Joe Hunt that I never got to enjoy.

The lobe should be just starting to open the points when advanced; if the follower is on the peak, it is advanced too far.

Good luck!

...Cotten

frankovy
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Joined: Sat Apr 16, 2005 2:19 pm

timing

#3

Post by frankovy » Fri Aug 11, 2006 3:15 am

ya i pulled the plug and stuck my thumb you nowhere and kicked with right hand.

frankovy
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Joined: Sat Apr 16, 2005 2:19 pm

timing

#4

Post by frankovy » Fri Aug 11, 2006 3:19 am

your right about the lobe then maybe i am to far advanced i set the slash to the front of the inspection hole. do you think it should be centered or
more to the rear of the hole.

fourthgear
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#5

Post by fourthgear » Fri Aug 11, 2006 12:47 pm

frankovy
I'm don't know enough about Mags. to tell ya , but if you have a manual adv. circuit breaker ( distributor ) ,The timing mark is to the rear of center of hole and if you have an auto adv. system its in the middle of timing hole , kinda dead center. Of course the rear of the hole is to the rear of the motor. Some have played with where its at for diff. cams.

Cotten
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#6

Post by Cotten » Fri Aug 11, 2006 1:52 pm

With any ignition, I get her started with a rough static timing and then strobe to the middle of the hole. If the motor suffers from bad gas (pinging from high compression or heavy load), then a little forward might be wise.

I also suggest using the front pushrod to determine the compression stroke, as occasionally the exhaust stroke will produce an apparent compression at the sparkplug hole.

...Cotten

frankovy
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Joined: Sat Apr 16, 2005 2:19 pm

timing

#7

Post by frankovy » Fri Aug 11, 2006 4:28 pm

should the front push rod be unmovable at compression stroke?

fourthgear
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#8

Post by fourthgear » Fri Aug 11, 2006 5:19 pm

frankovy
The reason you check with the front intake push rod is to know that you are on the intake stroke and then of course you use a plastic straw ( both plugs removed)into the spark plug hole and as you continue turning the motor over , with the straw you can feel the piston comming up on compression stroke . when its comming up ( slowly), you need to watch the timing hole for your timing mark to come by and it is real quick and easy to pass up , if you do pass it ,just go thru the same proceedure to get it again , you don't want TDC you want BTDC , I don't use a strobe type light with point type ign. , I only use static timing , now electronic ign.s are diff. I do use a strobe type light. In answer to your question , the intake valve should be completely closed on compression stroke ,depending on where the piston is at and what cam you have in there .

frankovy
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frankovy

#9

Post by frankovy » Fri Aug 11, 2006 8:56 pm

where should the piston be at tdc. more importantly where should the piston be at btdc.

is this right tdc is just before the piston reaches the top of the cylinder compression stroke.
btdc is just past tdc please explain this may be my problem.
thanks for quick responce
frank canada
ever in ontario canada email me and come and visit not many panhead people up here i might be the only one. the rest are new h/d people.

Cotten
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#10

Post by Cotten » Sat Aug 12, 2006 2:51 am

Frank!

Just for clarity,

Please drop your front intake pushrod cover and watch the pushrod go up and down as you turn the motor through slowly. (Naturally, removing the sparkplugs makes that easier...)

As the pushrod is moving back down, then start watching in the hole for the line. At that point I like to use a mirror to see the hole as I bump the kicker with the bottom of my fist.

Static timing (meaning no strobe) gives a slightly retarded setting, so the Manual suggests putting the line slightly to the back of the hole. The middle will do fine, believe me!
Your piston will be at the proper distance before top dead center.

Then proceed to adjust your circuitbreaker.
(Naturally you will have gapped your points and made certain that your advance control linkage is in order beforehand.)

Let us know how it goes...


...Cotten

Red55FL
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2012 Heritage Softail Classic
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#11

Post by Red55FL » Sat Aug 12, 2006 4:45 am

Frank
To answer your earlier question:
TDC is Top Dead Center - the piston is at the very top of it's stroke.
BTDC is Before Top Dead Center - the piston has not yet reached TDC.
The timing mark is BTDC & the spark should happen just as the crank rotates the timing mark to the center of the timing hole.

Red

frankovy
Posts: 37
Joined: Sat Apr 16, 2005 2:19 pm

frankovy

#12

Post by frankovy » Sat Aug 12, 2006 5:34 am

thanks guys everythings set for saturday morning just incase it works
i don't want to wake up my neighbor he's a little crazy but a nice guy.
your new friend in canada! eh!
frank

mbskeam
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#13

Post by mbskeam » Sat Aug 12, 2006 5:50 am

BTDC=35deg, or 7/16 down from TDC


mbskeam

Red55FL
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2012 Heritage Softail Classic
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#14

Post by Red55FL » Sat Aug 12, 2006 12:46 pm

mbskeam
I know that this is a dumb question & once it is answered I will think it should have been obvious.
I have seen the "7/16 down from TDC" in reference to HD timing written several times & for the life of me I can't seem to grasp what it means.

7/16 of what?

Red

Cotten
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#15

Post by Cotten » Sat Aug 12, 2006 2:23 pm

Red55Fl!

It would be more accurate to say: 7/16" before TDC

In other words, the crank is turned to where the piston is coming up and stopped 7/16" before it reaches it full travel, and the circuit breaker is then static timed at that position.

...Cotten

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