Timing with a pamco.

[ninskrillz]

So tomorrow in going to check the timing on my 71. It has a pamco ignition. I've never timed an engine before. I've tried to find the answers in looking for but came up short.

How do I advance/retard the timing with a pamco ignition? Do I loosen and turn the pamco plate? Do I have to test both cylinders?

I understand how the timing gun works (pretty much). I also intend to check the advance weights and springs to make sure they still have a nice snap. Got myself a nice cheap timing light from harbor freight (same one Mike's sells). Any tips greatly appreciated.

 

[pamcopete]

ninskrillz,

1. Starting with the timing light itself. You may find that it skips a beat once in a while. They just don't make em like they used to, especially the cheaper ones.
2. The PAMCO ignition is a wasted spark system, just like the stock TCI, and as such it produces a negative voltage on one of the spark plug wires and a matching positive voltage on the other.
3. The timing light works best on the negative wire as that is the polarity of a conventional distributor type ignition.
4. There is no easy way to tell which wire is negative.
5. Try both wires and use the one with the most stable operation.
6. Locate the small slot on the flywheel and paint it with something white, like paint.
7. The timing light will strobe the flywheel and "stop" the image to show where the slot on the flywheel is relative to the timing marks "T", "F" and full advance.

8. The timing mark should be on the "F" mark at 1200 RPM.
9. The timing mark should be at the full advance position at 3200 RPM.
10. To adjust the timing, loosen the screws holding the PAMCO plate and rotate the plate clockwise to advance the timing and counter clockwise to retard the timing.

 

[ninskrillz]

Great write up Pete! Thanks for the info!

 

[JV650]

Wasted spark! now that explains it. for the longest time I've been trying to figure out
what the hell! one lead firing off one coil with two spark leads.

 

[PickleSlice]

Wasted spark! now that explains it. for the longest time I've been trying to figure out
what the hell! one lead firing off one coil with two spark leads.

Quick explanation - http://www.gillcontrols.com/ignition-explained/wasted-spark-non-wasted-spark-ignition/

 

[pamcopete]

About the only downside to a wasted spark system with a single dual output coil is that one of the spark plugs wires is positive while the other is negative. Spark plugs are about 40% more efficient with the negative voltage because that causes the hot tip of the plug to emit electrons and the heat helps to propel the electrons from the hot tip to the relatively cold ground electrode.

That is why dual output coils are always "high performance" coils because the spark plug with the positive wire has to have 40% more energy to do the same job as the hotter tip on the negative wire plug. So, both plugs have the higher voltage, but only the positive plug really needs it.

This phenomena also means that some exotic spark plugs, like the Iridium's, are really only beneficial with the hotter negative spark plug wire. It's a waste of money on the positive wire. Ford recognizes this phenomena by providing a different spark plug for the positive and negative spark plug wires in their wasted spark engines, which virtually all engines are now.

 

[JV650]

Pete,

So on the feed and caring of your e-ignition it mentions something to the affect of not
leaving the ignition on without running the bike. Where as the e-advance has an auto cut-off. I plan on putting in the e-advance at somepoint, in the meantime can I just put a cut-off switch in until that time so I can have the ignition switch on with out worrying about
burning up the e-ignition?
Would a low voltage/amp switch be ok, I've got a mini rocker rated at 6amp@250vac. would this be ok?

TIA.

Oh and what lead would I want this switch to be on to disable the e-ign?

 

[pamcopete]

JV650,

That's called a kill switch and it is standard equipment on all motorcycles.

 

[JV650]

Ya understood, I'm looking at tucking in a small switch hidden away. extra security.

thanks
Jim

 

[mikeh36]

So I attempted to set/check the timing tonight. At 1200 rpm the timing mark was bang on the F. Had my wife bring the idle up to 3200 rpm and the timing mark stayed bang on the F. It didn't move at all. Not sure what to do now.

 

[5twins]

Check to see if the advance unit is working. It sounds like its not.

 

[mikeh36]

Thank 5twins. I'll check that tomorrow night. Just did a little research and if I'm understanding correctly, as I apply throttle the weights should spread away from the advance rod correct? I know I did a slap test on the weights when I installed the rod but I've never looked at it since.

 

[5twins]

Yes, the weights fling out as RPMs increase. The inner ends of them fit in slots in the little disc mounted on the end of the advance rod. When the weights fling out, they turn that little disc and the advance rod about 1/8 turn. That turns the points cam, or in your case, the Pamco rotor, on the other end of the advance rod to a different position. It rotates it "ahead" slightly. That's what advances your timing. The "trigger" on the rotor now reaches the pick-up on the backing plate a little sooner. The cylinder fires a little sooner or more advanced.

So, do that "slap" or "snap" test on the advance unit again but watch to see that the advance rod is actually being rotated a little bit as you pull the weights out to their stops. If the rod isn't turning then you're not getting any advance.

 

[mikeh36]

Thanks 5T. I'll look at it tonight.

 

[mikeh36]

My week got in the way of working on the bike but I got a chance this afternoon to pull the advance cover off and check the advance unit is/was working correctly. First I pulled the weight away from the disc and the disc does rotate without any problems. Then I fired the bike up and put my timing light on the advance unit. When I gave it throttle it weights did spread out and as far as I can tell the disc did rotate a bit as well. It was tough to tell as I was trying to keep the timing light on the AU, give it steady throttle, and keep the damn bike from walking across the garage floor.

At this point I'm at a loss on what else to look for. The AU is new with the PAMCO ignition in June. Is there a chance the springs that came with the kit I got from xs650Direct are too stiff (saw on another posting where someone had shortened theirs and the AU stopped working)? The bike seems to run okay and has decent throttle response (I'm past the hammer the throttle and race through the gears stage of my life). I did notice the last time I had it out to warm it up before checking the timing that I was getting "idle" hang where the idle would get itself stuck around 2000 rpm, I'd adjust it down, after a minute or two I'd have to adjust it back up, then the next time I cracked the throttle it'd hang again. I don't know if that's because something is foobar'd with the AU or if it's something else (couldn't find any air leaks) but I figure one problem at a time. I'm on the verge of ordering Pete's electronic advance but the Mrs. is starting to question the amount of $$ I'm spent.

 

[5twins]

If the little advance disc is rotating that should turn the advance rod with it, along with the Pamco rotor attached to the other end. The timing should advance then. The hanging idle speed could indicate the advance rod is sticking in the advanced position. And, maybe it was stuck in the retarded position when you did your timing check. That's maybe why you saw no advance happening. With the motor off, work the advance unit by hand. Turn the little disc and advance rod full open then let go of it. The springs should snap it back quickly to the retarded position. It should turn by hand pretty easily and smoothly. Do you have the bushings at both ends of the cam greased up good where the advance rod passes through them? You need to keep the advance rod lubricated for it to work right.

 

[mikeh36]

I did grease the rod pretty good (I think) when I installed it. I didn't put a thick layer of grease, just a thin uniform layer. I didn't grease the bushings themselves as I thought the grease on the rod would take care of that. I'll check the movement by hand and see what happens. Should I be adding grease to the outside of the bushings as well?

Edit: Out in the garage now. My fat fingers can't get a grip on the AU disc but I can turn the rotor disc easily an the weights open and snap closed when I release the rotor.

 

[5twins]

It sounds like everything is working as it should. Maybe your timing light was giving faulty readings? A dual output coil flows the current down one plug wire, through the motor, then back up the other plug wire to the coil. That makes one plug wire technically a "+" charged wire and the other a "-". Some timing lights work better on a certain type of wire charge, giving erratic readings on the other type. Try your timing light again except hooked to the other plug wire, not the one you used the first time around.

If you have the stock advance rod bushings in the cam, the outer ones will have grooves around their I.D. like so .....

Those grooves are there to retain grease, a reservoir so to speak. Pack them full of grease and the rod will have a good supply of lube for years .....

Figure on pulling the rod and refilling the bushings every 5 or 6 years.

 

[mikeh36]

I did try both plug wires on the idle timing but didn't see a notable difference and I think I tried it when I was trying to get the advance timing but I'll give that another shot. The bushings came as part of the pamco ignition kit and are smooth brass. Thanks for your help 5T

 

[mikeh36]

Looks like I didn't seat the locating pin for the ATU to guide onto properly so my guess is it was slipping under high rpm causing the lack of advance. Still haven't got it timed because it's pissing rain so no warm up run but a cold timing showed the timing marks advancing.

But I do have a question... I understand I have to rotate the PAMCO plate to adjust the timing but if I get it set properly at idle (right now it's on the T instead of the F) and it's off at full advance, any changes I make will affect the idle timing. Or is it a case of finding a happy medium?