Timing WAY too advanced

[franklin270h]

So I was firing up my 77 today. PAMCO ignition and e-advance. Initially when I went to fire it up, was struggling to get it going, had some pretty fierce kickback and backfire out of the carbs. Retarded the timing enough and got it to start, but was still extremely far advanced. On a timing light, PMA with Hugh's sticker to line up, fire mark is at ~6:00, was firing at nearly 9:00 way past the advance mark, that was at about 1500-2000 rpm (was struggling to get it to idle at that point just due to advance, had to hold the throttle some) and at that point was completely out of room on the plate cutout notches for adjustment. I shut it down just so I don't risk holing a piston.

I double checked TDC, which both pistons are at the top right on the mark, and camshaft locating pin is dead at 12:00 when at TDC, so I don't think it jumped a tooth or anything. Advance rod is stock one, locating pins in the same direction on both sides and i filed them to fit snugly into the channels for the rotor and advance replacement, they sit flush against the rod. Which with the e-advance I don't think you can be 180° out anyway given it has eliminated mechanical advance as a factor, but they are right regardless and pointing same direction. Cam chain tensioner and valve lash adjustments check out too. I also double checked the board mounting location on the pamco plate and it's right where it should be compared to all pictures I've seen, rotor also has all magnets in place and it is a 60° one. I unscrewed the e-advancer box and checked all solder joints and components and everything looks in order as well. It had points on it prior to and was fine on the timing, though I had the bike apart painting/restoring it so it has been a while since I've had an A/B comparison, I didn't do anything to the motor since then though.

I'm at a bit of a loss on it. Has anyone experienced anything similar to this?

 

[XSLeo]

How did you determine TDC?
Depending on how you did this you can have the timing marks wrong.
Leo

 

[franklin270h]

I sharpied alignment with the original stator as a safe measure to know I was in the ballpark, then for final precise mark i used a piston stop. I didn't have a degree wheel but I marked both and then marked the middle point between them on PMA rotor with a caliper, and that was right at where the original mark was as well. I've even shined a flashlight into spark plug holes and can see them at the top of the bore, even watched the dwell just to make sure. Part of why I'm at such a loss on this, I've double and triple checked tdc and cam but these are usually the kind of problems that you missed something really dumb.

But the other is, it's running like it is advanced. Barely able to start, kicking back pretty furiously and occasional backfire out of carbs, running really rough and it won't run much at all until you get >2000 rpm or so.

 

[scabber]

You might check to see if the pin that holds the trigger wheel is in place and it is in the correct position.

 

[pamcopete]

franklin...,

There are three locating pins for the ignition. You have identified two of them on either end of the advance rod, but there is a third one in the cam itself that locates the advancer replacement cap on the right side.

Here shown with the mechanical advancer plate.

Also, I think I have posted this 1,000 times, but here is 1001. Temporarily connect the ignition to a fully charged stand alone battery that is not connected to the PMA and see if the engine runs better that way. If it does, then your problem is the PMA and not the ignition.

 

[franklin270h]

franklin...,

There are three locating pins for the ignition. You have identified two of them on either end of the advance rod, but there is a third one in the cam itself that locates the advancer replacement cap on the right side.

Here shown with the mechanical advancer plate.

Also, I think I have posted this 1,000 times, but here is 1001. Temporarily connect the ignition to a fully charged stand alone battery that is not connected to the PMA and see if the engine runs better that way. If it does, then your problem is the PMA and not the ignition.

The camshaft locating pin has been in place the whole time, I filed it down too and made sure the advancer replacement fit flush against it. No play on either side as well. The locating pins for the rotor and (what used to be) mechanical advance are facing in the same direction.

I also did separately connect a battery to the unit and isolate it from the rest today when i took another stab at it. I suppose here comes the strange(r) part. Before i started i verified ignition itself, pulling a pin and rotating the rotor by hand with one plug out and grounded, which everything is firing as it should and getting a strong spark. Reassembled everything as it was before, results were the same. I was still at a bit of a loss, and was curious to see if retarding it further would help so I (which i competely understand is at my own risk) moved the PAMCO board to the opposite slot and reoriented the plate, so the board/sensor sat higher. Motorcycle fired right up after like 2 kicks, I put a timing light on it and set it up to fire mark at idle. Ran smoothly, idled, when i gave it throttle the advancer worked as it should. I left it there and it ran for a good probably 15 minutes while I was dialing in the carburetors and then I cut it off, came back later and it fired right up as well.

It's odd to me, and I'd actually understand it more if I were like 180° off or 90° off or something fairly "even" to crank/cam rotation. I didn't want to put anything PAMCO specific in the thread title because I'm not sure it is anything with the unit, which seems to work just great. I was glad to see the bike running nice and smooth but still a little bit stumped on the cause (when I was running it the PAMCO was on its own battery as well).

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[franklin270h]

Actually, and thinking out loud here, with the ignition is the first magnet or the trailing magnet the one where the spark plug is supposed to fire?

When I was testing the system (rotating the rotor with a locating pin pulled so i could freely spin), the spark plug was firing when the first magnet passed over the sensor when turning counterclock. I tried another rotor that I had ordered as a spare just to make sure the magnets weren't reverse polarity and the result was the same.

If it's supposed to fire with the first magnet disregard this, just was thinking because as far as the timing lining up that's almost the exact distance i had to place the sensor compared to original location and it runs great. I know hall effect sensors essentially create a positive/negative voltage dependent on what polarity magnetic field passes over them, wondering if something might have gotten inversed somehow?

Included an image to show what I'm referring to. And my sensor currently is right about where the top/first magnet that i highlighted in the picture is.

 

[pamcopete]

Franklin,

The large transistor that you refer to is actually the coil driver, not the sensor, so I gather that you have the original PAMCO with the E-Advancer added on?

The hall effect sensor is that very small transistor looking device on the PC board, so when the first magnet is over the driver transistor, the second magnet is over the Hall sensor and the first magnet has already passed over the sensor to turn the coil on. The second magnet, as you described, is the magnet that turns the coil off to cause the spark.
So, it sounds like you now have the PAMCO working OK?

I'm just curious to ask if perhaps you had the advance / retard plate directions reversed? Moving the plate clockwise advances the spark. Moving the plate counter clockwise retards the spark.

 

[franklin270h]

Franklin,

The large transistor that you refer to is actually the coil driver, not the sensor, so I gather that you have the original PAMCO with the E-Advancer added on?

The hall effect sensor is that very small transistor looking device on the PC board, so when the first magnet is over the driver transistor, the second magnet is over the Hall sensor and the first magnet has already passed over the sensor to turn the coil on. The second magnet, as you described, is the magnet that turns the coil off to cause the spark.
So, it sounds like you now have the PAMCO working OK?

I'm just curious to ask if perhaps you had the advance / retard plate directions reversed? Moving the plate clockwise advances the spark. Moving the plate counter clockwise retards the spark.

I had just drawn on the example pic from your site for that one as i didn't have any pics of mine and it was dark, I will try to grab a picture of mine if i have some daylight when i get off work.

Internet is hard to get every detail right so I'll try to retrace as clearly as I can

I have the newer simplified PAMCO plate meant to work with the E-Advance that doesn't have the driver transistor on the PAMCO board (which shipped 4/12, franklin is my last name) To get the timing retarded enough for it to align and run well, I had to unscrew the PAMCO board and flip the plate, which moved the board closer to the top left plate mount and effectively delayed the timing.

So right now, the hall effect sensor is located about where the first magnet is on the picture I drew on (which that picture I pulled from your website because it was nice and clear), if you were to draw a line from the middle prong of the hall effect sensor to the outside of the housing it would be pointing to between 12:00 or 1:00 I'd guess, or if comparing to an original pamco, roughly between where the screw mount and top of the driver transistor would be. Where the original location the hall effect sensor is closer to 3:00.

Things I have verified: all locating pin orientations correct, TDC, cam position relative to TDC, all wiring which has been soldered and heat shrinked, put the unit on an independent circuit with a battery that was reading 12.6V, when the bike was running I put a multimeter on the charging system with PMA and it was reading high 13V/low 14V range. I've also done a separate test with the bike off and a locating pin pulled while spinning the rotor, watching the spark, while rotating it counter clockwise I noticed the plug was firing when the first magnet passed the sensor.

So currently, it is working. Given that, the only concern I have is why I had to relocate it, and if somehow polarity could be a reason i had to. I'd be more than happy to grab pictures or put a multimeter on anything if it helps

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[pamcopete]

franklin...,

Yes, a pic would help explain what you did to get it to work.

 

[franklin270h]

franklin...,

Yes, a pic would help explain what you did to get it to work.

I might run out of daylight but I'll try to grab a picture or video when I get home. Thanks

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[franklin270h]

Grabbed a video of it, which hopefully gives a clear idea as to where the board and sensor are positioned to get the timing to line up, the physical location I flipped the plate the board mounts to so that it would effectively retard the timing. I pulled a locating pin in the advance rod and put the rotor on without the washer to show where the magnets are relative to the sensor. You can see the spark if you look closely but hopefully you can at least hear it, it seems it is firing as the first magnet passes. I've done that with two different rotors, results are the same.

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[pamcopete]

franklin...,

I think what's happening is the E-Advancer is "confused" by the very slow rotation of the rotor and fires when the first magnet of the next cycle is over the sensor. Try using your timing light shinning on the rotor with the engine running to see where the magnets are when the spark occurs. The E-Advancer algorithm is very dynamic, never static, so other than checking for spark, rotating the rotor will not give you an accurate picture of where the magnets are when the spark occurs.

As for the position of the plate, it is in a severely retarded position, but that is just a reflection of the relationship of your cam to the crank timing marks and you were not able to obtain a more normal location without changing the mounting position of the PC board.

I would suggest at this point that you temporarily reinstall the stock alternator rotor to verify your timing.

 

[franklin270h]

Apologies for late reply. I will do that and pull the PMA and go back to stock rotor whenever I get a chance, looking like it'll be another week or so due to an emergency work trip

 

[bill selkirk]

Any update on your timing issue, i installed the PAMCO ignition and e-advance and i am having the exact same issue...

 

[pamcopete]

The timing at idle will only be true with the engine idling at or below 1200 RPM. If your idle speed is greater than 1200 RPM, the E-Advancer will introduce some advance. The stock mechanical tach may not be accurate at 1200 RPM, so either get a better tach or set the timing for full advance at 3200 RPM or set the idle to the lowest you can without stalling the engine.

Also, sometimes there is confusion about which way to move the PAMCO plate to set the timing. Moving the plate in the clockwise direction advances the timing. Moving the plate in the counter clockwise direction retards the timing. Clockwise means the same direction that the hands move on an analog clock or watch.

 

[ebb0tk]

Im awakening the the thread a bit. Although im not running a pamco (heiden 277 ignition) same principle i guess. Im Iooking at same problem, too much advance (past mark) when revving 3k+. Idle set between F marks. Its bouncing pretty much too, the mark on stator. New springs and clips on atu, greased advance rod but didnt grease the weigth pins and for reference, the ears on the weights feel sloppy in the slotted disc. Should i peen them to tight fit as a first test too se if it helps?

I think i was over full advance mark of atleast 5-8 degrees. If i remember correct.

Any other things i should check?

Ive adjusted cam chain and Valve lash so all Good there.

 

[TwoManyXS1Bs]

... Its bouncing pretty much too, the mark on stator.
... the ears on the weights feel sloppy in the slotted disc. Should i peen them to tight fit as a first test too se if it helps?

Do a forum search on "drag finger", posted by "TwoManyXS1Bs".
Read the first 5 results...