Points timing trouble
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Cruiser
Joined: May 2013
Posts: 129
Likes: 8
From: Norfolk
Points timing trouble
I'm a little stuck here. I pulled my cam cover off to have a look in the gearcase of my new shovel the other day. The bike was running very strong when I got it home. I just sat down to time the bike and it's giving me hell. I've watched every video on the subject, read every forum post and just not getting anywhere. Can anyone 100% confirm which lobe I'm supposed to be going off with my test light? I have read it's the narrow lobe, but I am having trouble even getting the narrow lobe anywhere near the points lifter when the TDC mark is in the window. The adjustability just isn't there. How do I confirm that I've put the lobe mechanism on correctly, seeing as it will go on two ways?
Seasoned HDF Member
Joined: Nov 2006
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From: la la land jerzey
You have 2 things that must be in place before it will work for you
one points require that the advance mark and not TDC mark is used - but the engine Must be firing on the front cylinder
then the small lobe is front cylinder and it must be turned against the advancer in the cone to full advance BUT the point gap needs to be correct before you do anything
when all the ducks end up in a row it will seem easy - its a forehead slap
one points require that the advance mark and not TDC mark is used - but the engine Must be firing on the front cylinder
then the small lobe is front cylinder and it must be turned against the advancer in the cone to full advance BUT the point gap needs to be correct before you do anything
when all the ducks end up in a row it will seem easy - its a forehead slap
Road Master
Joined: Feb 2010
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I’m certainly not in John’s league when it comes to expertise but as he says, first set the points. Jack up the rear wheel and remove the plugs. John uses a straw in the front cylinder but I put my finger over the spark plug hole to feel the compression on compression stroke. Fully advance timer and set timing. By raising rear wheel, you get all the lash out and you can be on the left side of the bike to see the advance mark in the window. Once you’ve done it a couple of times, it becomes old hat.
Thread Starter
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Cruiser
Joined: May 2013
Posts: 129
Likes: 8
From: Norfolk
Ill try timing to the advance mark with the lobes advanced, but it just doesnt seem right to me that I cant even get the narrow lobe to make contact in the base timing position.
Last edited by Aaronbagby; Apr 4, 2021 at 09:18 AM.
Thread Starter
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Cruiser
Joined: May 2013
Posts: 129
Likes: 8
From: Norfolk
I had the cam cover off to go through it. I would not buy a 45-year-old motor just to run it until it blows without looking through it first.
Anyways, something way fishy is up. With the flywheels showing the solid line (TDC) on compression stroke, the narrow lobe on the cam follower is just too far away to make a spark with the advance weights swung out. By the time its within range, the points plate is so far clockwise that a screw wouldnt even be going into the aluminum backing anymore.
Knowing that absolutely anything could have been done to the motor since 76, I decided to confirm that the timing marks even matched up with anything. With TDC mark in the window, the rear cylinder is higher than the front. I suppose someone could have stroked the flywheels and then neglected to mark anything.
For clarity, the flywheels have three marks. The first to show up in the window is a single dot dead center, the second is a solid line, the third is another single dot but lower in the window. Does this correspond with any HD or known aftermarket schemes? Im aware of the early-model being a line for advance and a dot for TDC, and the late model being reversed, but never seen anything referincing a third single dot. What should my next move here be?
Anyways, something way fishy is up. With the flywheels showing the solid line (TDC) on compression stroke, the narrow lobe on the cam follower is just too far away to make a spark with the advance weights swung out. By the time its within range, the points plate is so far clockwise that a screw wouldnt even be going into the aluminum backing anymore.
Knowing that absolutely anything could have been done to the motor since 76, I decided to confirm that the timing marks even matched up with anything. With TDC mark in the window, the rear cylinder is higher than the front. I suppose someone could have stroked the flywheels and then neglected to mark anything.
For clarity, the flywheels have three marks. The first to show up in the window is a single dot dead center, the second is a solid line, the third is another single dot but lower in the window. Does this correspond with any HD or known aftermarket schemes? Im aware of the early-model being a line for advance and a dot for TDC, and the late model being reversed, but never seen anything referincing a third single dot. What should my next move here be?
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
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From: la la land jerzey
If you have someone who owns a shovel pan knuckle iron head sporty even an evo bike of anykind and they have tuned the bike themselves — they under stand your 180 out of time - not every time the mark come into the window its firing front cylinder its every other time it comes into the window
think about that and start over -
think about that and start over -
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Thread Starter
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Cruiser
Joined: May 2013
Posts: 129
Likes: 8
From: Norfolk
If you have someone who owns a shovel pan knuckle iron head sporty even an evo bike of anykind and they have tuned the bike themselves they under stand your 180 out of time - not every time the mark come into the window its firing front cylinder its every other time it comes into the window
think about that and start over -
think about that and start over -
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Tourer
Joined: Oct 2020
Posts: 419
Likes: 256
From: Zurich
The lobe thingy only goes one way in the advance mechanism.
My bike had points when I got it, was also running strong. The timing was set all the way retarded, but was still too early. Apparently there are points for sale which are actually from a Chevy, which fit the shovelhead but will cause wrong timing to the point it cannot be adjusted correctly.
I got a dynatek DS6-1 and ditched the points. Main reason is that the lobe height affect the timing interval between the cilinders, and is very hard to get correct. With a magnets style ignition like Dynatek the interval depends on the magnet placement, which I think is more accurate.
My bike had points when I got it, was also running strong. The timing was set all the way retarded, but was still too early. Apparently there are points for sale which are actually from a Chevy, which fit the shovelhead but will cause wrong timing to the point it cannot be adjusted correctly.
I got a dynatek DS6-1 and ditched the points. Main reason is that the lobe height affect the timing interval between the cilinders, and is very hard to get correct. With a magnets style ignition like Dynatek the interval depends on the magnet placement, which I think is more accurate.