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60 panhead, stroker motor. Only marks are two slashes one with 3 dots center punched around it and seems to be rear cylinder TDC mark. The slash behind it in rotation is just a slash and doesn't seem to line up with anything. Bike runs fine with points static timed off the front cylinder at TDC. Is it passable to just static time the dyna s off the rear cylinders compression stroke at TDC? 35 degrees is a guessing game without a degree wheel. It was running but the rpms where staying high when I backed off the throttle which could be carb related. I thought it was perhaps timing as it is a bitch to start warmed up. I do not have a manifold leak as I already checked that with a block off plate. Anyone chime in?
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Details: 1960 panhead stoker (fresh rebuild) I think 89-91 inches. Super E carb. .0295/80 i think. Dyna S ingtion. pushrods are right. solids, spin freely after both valves close. -
Timing plug hole is 8 degrees wide, if it's the usual 5/8-18 hole. If you have an actual rear cylinder TDC mark, and put it just forward of the front edge of the timing hole, that is 40 degrees BTDC of the FRONT cylinder. (Rear cylinder TDC is equal to 45 degrees BTDC of the front cylinder.) If the mark "following" your rear TDC mark is almost appearing at the rear of the timing hole as the rear TDC mark has just left the front of the hole, then that second mark is your front cylinder 35 degrees BTDC timing mark.
Are you advancing the ignition rotor against the advance weight springs when setting the timing using the advanced timing mark? Or is this a manual advance timer?
JimComment
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.031/.076 may be a better starting point for your jetting with a Super E on a pan (or shovel) stroker.
JimComment
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All great info, thank you. I have never seen marks in this order, but will verify the info you shared in the morning (I'm sure you're correct). If that second mark following rear TDC denotes advanced for front I am correct in thinking that if the rear is at TDC on its compression stroke the following slash is 180 out?
Regarding timing, per dynatek, due to it being in a reverse application you time off of the rear cylinder advance mark (which I do not have) Due to a lack of mark I have timed by the following:
Bring rear to TDC on compression stroke
rotate plate to fully retarded position (counter) then advance (clockwise) until I see and hear the plugs fire. I am not advancing the spring weights when I time with this procedure.
Any suggestions Jim?
Thanks in advanceComment
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When you are using a Dyna S in a timer that turns clockwise, the rotor magnets are simply triggering the pickup in the reverse order from the "normal" application in a cone motor where the timer turns counterclockwise. You still time the motor with the front cylinder advance timing mark in the usual manner. I don't know why Dynatek would tell you to time it with the rear cylinder advance timing mark (which as you note, not all flywheels have). That advice just complicates the procedure unnecessarily. Time it just like you would if you were using points.
If you have an automatic advance timer, then you MUST advance the rotor against the advance weights and springs if you are using the advance timing mark on the flywheel. As you note, the beauty of the Dyna S is that it will fire the plugs at zero rpm, making static timing easy and foolproof. (Lots of fuel motors used the Dyna S to trigger their ignition, and this easy timing setting is one big reason.)
As far as the marks on the flywheel go, remember that the full cycle of a four stroke motor is 720 degrees, or 2 full turns of the flywheel. Piston down, up, down, up; suck, squeeze, bang, blow. But any and all of the timing marks can only be put on the flywheel in its 360 degree circumference. So the front and rear cylinder marks are not 180 degrees out, they are 360 degrees, plus or minus 45 degrees, out (for the 45 degree v-twin).
I hope this helps you. I may have only made it clear as mud.
JimComment
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Dude, absolutely my thoughts as well on the timing procedure they use in this application. I will try timing off the front advance mark and report back. Thank you for clarifying everything, it has been helpful knowing that I'm not the only one that is thinking the way you are. Hopefully everything works.Comment
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Jim. Couple things. Changed my slow jet to a .31 still at a .72 main (will tune later) This is where I'm at. I've double checked wiring, it is correct. I've double checked the rotor for the dyna S is not 180 out and it is not. I've changed plugs to AC Delco 45s (what the parts store had that fit). I've set timing, holding the rotor in the advanced position, to the front cylinders advance mark, immediately after rear TDC mark (can view both in window) on the front cylinders compression stroke. It is coughing at the carburetor and sometimes wants to act like shes gonna fire. Would I be correct in thinking the timing is too far retarded from these coughs? I'm getting ready to go back to points, lol. Thanks brother.Comment
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First, the timing hole is 8 degrees wide, and the rear cylinder TDC mark is 10 degrees away from the front cylinder advance timing mark, so you should not be able to see both in the hole at the same time. (You might see both by looking past the edge of the hole, like looking around a door jamb.)
For the Dyna S rotor, be SURE you are using the right magnet for your front cylinder. Find the two magnets and draw lines from each to the center of the rotor. You will have a very shallow "V", 157.5 degrees actually. Looking at the "V", the right side magnet will be your front cylinder magnet, on a timer that turns clockwise.
If you are unsure of your advance timing mark, you can time the motor to idle timing, which is NOT ideal, but WILL result in decent starting if the motor is good. For this method, find the front cylinder TDC with a wire or straw through the plug hole, feeling for the piston at TDC. Find that front cylinder TDC mark, and mark it with some paint or something so you can find it later. Turn the motor over in the normal direction until the front intake valve opens and closes. Continue to turn until you see that front cylinder TDC mark just visible at the REAR of the timing hole. On your timer, the front cylinder magnet needs to be a little clockwise from the pickup. With ignition on, turn the body of the timer counterclockwise until the plugs fire. Lock it down there.
If you can't kick this motor to life after doing the above, there is something else wrong. I did the above in a campground parking lot with few tools, and the motor fired right up. You should be able to have the same success.
JimComment
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Never even open the timing plug when installing ignitions. Points, electric, or electronic.
Don't break out a test light either.
Simply set the plate centered in the slots and clock it advanced 5-10 degrees.
This is close enough to start.
Then like on an ok ld Chevy, twist the distributor back and forth till the open door stops shaking.
In our case the bars or sissy.
In other words, set the plate for smoothest idle (warm).
If it's not dead simple like this.
You have other issues (like Jim says)Comment
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This is how I work it too!
These 55 year old motors weren’t technological marvels 75 years ago. They’re simple. We over complicate stuff.
When I try to get it exactly right the first time I find it difficult. If I go the simply “good enough “ route then tweak from there it seems to go a lot smoother.
Get it to start then tune from there.Comment
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This is my first psnhead. Its a 58 pan chopper. 4 5/8 s&s wheels. My question is this. Just how did you get the dyna s igntto mount into the distributor? Did you make a mounting plate for it , do we use the advance weights because my distributor doesn’t use those. And the rotor swap? As you can see im green on the panhead stuff but good with shovels and evo’s. Thanks for any help given here. I attached some pics of my pan build.Attached FilesComment
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...how did you get the dyna s igntto mount into the distributor? Did you make a mounting plate for it ,
Found this; look at links in posts:
"If you really want to hide that Dyna, you can convert a stock HD timing cup in about an hour. I've done a few of these for friends."
If buildin' old school choppers was easy, anyone could do it... ain't nobody said it's gonna be easy...Comment
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