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    Default Timing cone shovels (and ironheads) with points

    I just wrote this up, in answer to a PM, and I thought I would post it here. Probably been done a hundred times, so here is #101:

    If you have the original points, then you can static time the motor, and as a final check you can use a strobe timing light if you wish.

    First step is to remove the point plate, and then remove the mechanical advance unit for inspection, cleaning, and lube. On these older bikes, most of the advance units are worn out and in need of replacement. If the weights are flopping around on the pins, the unit is toast.The import replacement advance units are serviceable and will last for a couple of years if properly lubed. White lithium grease on the pins and center post and all points of contact is the way to go. Install the advance unit being sure the drive pin is in the slot on the cam nose. Tighten the bolt gently, remember it is only a 10-32 size, despite the 9/16 hex head.

    Once that is handled, set the point gap to .016 - .018 on each lobe. A difference of .002 between lobes is acceptable. If the difference is more, use a soft (aluminum or brass) drift and small hammer to bump the point cam toward the lobe with the smaller gap. Drift on the bolt head, and go easy. You may have to do this a couple of times but it's worth the trouble.

    Once the point gap is set properly, you can do the static timing. Find the advance timing mark on the flywheel:
    Remove plugs. Remove the timing hole plug.
    Jack up the bike so the rear wheel is off the ground, and put the trans in high gear.
    Roll the motor forward using the rear wheel, and with a finger over the front cylinder plug hole, feel for compression.
    Pay attention now, this ain't in the book: On the rear cylinder, with a screwdriver or piece of wire or whatever, feel for the rear piston to come to TDC as you continue to turn the motor forward with the rear wheel. If you have felt compression on the front cylinder, the rear piston should be near TDC, so you won't have to move the motor far. After the rear piston is at TDC, look in the timing hole and roll the motor forward a little bit. The advance timing mark will appear in the hole. Stop when it is centered in the hole. If your motor has the original flywheels, the advance timing mark will be a vertical line.

    Now, to set the timing, you must turn the point cam counterclockwise to the limit of the advance unit travel, which is full advance. I use some small 90 lock ring pliers, or small bent needle nose pliers to grab the point cam and twist it. You may need to unscrew the condenser and move it out of the way. You can let it hang by its wire. You want the points to just start to open as the point cam hits the limit of its travel. Adjust the point plate as needed to make that happen.

    You can use a test light with the lead clipped to the point wire, and the probe grounded. With the ignition on,the light will light as soon as the points start to open. Don't leave the ignition on, because it will fry the coil if you leave it on with the motor not running.

    After all this, you can check with a strobe timing light, looking for the advance mark to come to the center of the timing hole when the motor is revved up. You need one of the clear plastic plugs for the timing hole to keep the oil off you. I find that the static timing is sufficient if done correctly, and so I do not use a timing light on point and coil systems.

    Hope this will help someone who is new to the shovels or ironheads.

    Jim

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    Quote Originally Posted by JBinNC View Post

    Now, to set the timing, you must turn the point cam counterclockwise to the limit of the advance unit travel, which is full advance. I use some small 90 lock ring pliers, or small bent needle nose pliers to grab the point cam and twist i
    This tool is handy as tits on a milk cow ... Frees up both hands ...

    Click image for larger version. 

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    Locks the point cam at full advance ...

    (Allows you to fondle the ol' Lady) ..

  3. #3
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    Awesome, thanks.

    I remember you shared a neat trick about sliding a thin piece of brass tubing over the pins(?) and timing it at full advance statically as described above. Was that to help with starting? to adjust idle speed timing? Can you describe that again.

    Are there different timing marks for certain years?

    And wondering with aftermarket flywheels that may not have factory marks- is there a piston height measurement for full advance?

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    Quote Originally Posted by TriNortchopz View Post
    Awesome, thanks.

    I remember you shared a neat trick about sliding a thin piece of brass tubing over the pins(?) and timing it at full advance statically as described above. Was that to help with starting? to adjust idle speed timing? Can you describe that again.

    Are there different timing marks for certain years?

    And wondering with aftermarket flywheels that may not have factory marks- is there a piston height measurement for full advance?
    The advance weights have pins that fit into holes in the advance unit base. The holes restrict the movement of the pins, from one side of the hole to the other, and that is how the advance weight travel is determined. The advance unit should have 15 of rotational movement, and since it is mounted directly to the cam, that 15 equals 30 at the crank. That means if you set the advance timing for a big twin at 35 BTDC, then the starting and low idle timing will be 5 BTDC. You can press a piece of brass hobby tubing over the advance weight pins, thereby increasing their diameter. That in turn will limit the advance weight movement. So say that the advance unit only moves 13 after this mod. That 13 equals 26 at the crank. So if you set the advance timing in the usual way, at 35 BTDC, then your starting and low idle timing will be 9 BTDC. With even a mild cam upgrade, that small change can help starting and low speed response. This is called "tuning."

    In late '80 or early '81, H-D changed the timing marks so that the advance mark that had been a vertical line for 70 some years became a dot, and the front cylinder TDC mark that had been a dot became the vertical line. Since the flywheels can be swapped between the two styles in shovel motors, using the rear piston position to identify the advance timing mark is a quick trick to be sure you have the right mark, even if you don't know the details of the motor. That also goes for aftermarket flywheels which may have a variety of different marks.

    Jim

  5. #5

    Join Date
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    Default

    Quote Originally Posted by JBinNC View Post
    I just wrote this up, in answer to a PM, and I thought I would post it here. Probably been done a hundred times, so here is #101:

    If you have the original points, then you can static time the motor, and as a final check you can use a strobe timing light if you wish.

    First step is to remove the point plate, and then remove the mechanical advance unit for inspection, cleaning, and lube. On these older bikes, most of the advance units are worn out and in need of replacement. If the weights are flopping around on the pins, the unit is toast.The import replacement advance units are serviceable and will last for a couple of years if properly lubed. White lithium grease on the pins and center post and all points of contact is the way to go. Install the advance unit being sure the drive pin is in the slot on the cam nose. Tighten the bolt gently, remember it is only a 10-32 size, despite the 9/16 hex head.

    Once that is handled, set the point gap to .016 - .018 on each lobe. A difference of .002 between lobes is acceptable. If the difference is more, use a soft (aluminum or brass) drift and small hammer to bump the point cam toward the lobe with the smaller gap. Drift on the bolt head, and go easy. You may have to do this a couple of times but it's worth the trouble.

    Once the point gap is set properly, you can do the static timing. Find the advance timing mark on the flywheel:
    Remove plugs. Remove the timing hole plug.
    Jack up the bike so the rear wheel is off the ground, and put the trans in high gear.
    Roll the motor forward using the rear wheel, and with a finger over the front cylinder plug hole, feel for compression.
    Pay attention now, this ain't in the book: On the rear cylinder, with a screwdriver or piece of wire or whatever, feel for the rear piston to come to TDC as you continue to turn the motor forward with the rear wheel. If you have felt compression on the front cylinder, the rear piston should be near TDC, so you won't have to move the motor far. After the rear piston is at TDC, look in the timing hole and roll the motor forward a little bit. The advance timing mark will appear in the hole. Stop when it is centered in the hole. If your motor has the original flywheels, the advance timing mark will be a vertical line.

    Now, to set the timing, you must turn the point cam counterclockwise to the limit of the advance unit travel, which is full advance. I use some small 90 lock ring pliers, or small bent needle nose pliers to grab the point cam and twist it. You may need to unscrew the condenser and move it out of the way. You can let it hang by its wire. You want the points to just start to open as the point cam hits the limit of its travel. Adjust the point plate as needed to make that happen.

    You can use a test light with the lead clipped to the point wire, and the probe grounded. With the ignition on,the light will light as soon as the points start to open. Don't leave the ignition on, because it will fry the coil if you leave it on with the motor not running.

    After all this, you can check with a strobe timing light, looking for the advance mark to come to the center of the timing hole when the motor is revved up. You need one of the clear plastic plugs for the timing hole to keep the oil off you. I find that the static timing is sufficient if done correctly, and so I do not use a timing light on point and coil systems.

    Hope this will help someone who is new to the shovels or ironheads.

    Jim
    Great post on a commonly asked issue

    Id like to also add that I have seen allot of points setups on cones and sporties that also had worn/broken springs, pins and bushings, and/or wore out shafts that wobbled when run, which wont allow for any kind of solid timing and the owners would chase down fuel or electrical probs outside of the actual cause. Wore out shafts are fairly common on circuit breakers on early shovels, pans and knucks.

    I ran into that issue myself: Had a 64 pan that would start up in two kicks and idle all day long like a Singer: Then over time, kicking was more involved, and idle quality got worse, as did perf across the board: I did the whole timing check, new points, plugs, coils, PR adjustment, carb adjustment, etc. Finally, after a bad day of kicking, once I got it running, I removed the circuit breaker top and looked at the points while running: Quite a wobble as the shaft was just plain worn out. Fixed it, ran again like a sewing machine

    Another common prob I have found is a loose electrical wire connection at the points (where the wire from the coil attahces to the points).

    Folk's that inherit these type(s) of problem even have it worse as the cause will just get worse, and folks tend to chase their tails trying to nail the prob down

  6. #6
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    Default

    Another problem that the advance unit faces is Sporties with mega miles on them ..

    The cam cover bushing becomes worn far past max worn spec and causes the the unit to snap back after the cam lobe has went over high lift.
    This condition works the unit very hard and leads to rapid failure (Flyweights and Pins takes a beating) ...

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