Pamco timing question

[ann0yed]

I installed the Pamco today and my bike idles really well right where the mark is in the attached photo I took with the timing light. Is that right? What am I supposed to get that line on the rotor lined up with or in between? I thought I was supposed to line up with the line to the right of the "F" but that just made the bike stumble and die.

-jonathan

 

[5twins]

Your timing is too far advanced in that pic. At idle (1200 RPM), you should be somewhere between the 2 slash marks that have the "F" between them. At full advance (about 3K), you should be aligned with that unmarked slash to the far left.

 

[ann0yed]

Well it ran like crap in that range and seemed about to stall.

-j

 

[5twins]

The more important setting is where the timing ends up at full advance. Rev the bike to between 3 and 3.5K and put the timing light on it. You don't want the rotor mark to move to the left of that far left slash on the alternator. If it does, you're over-advanced and can hole a piston. Usually, if you're off at idle, you're off about that same amount at full advance. From your picture, you're pretty far advanced at idle. That would put you pretty far over-advanced at 3 to 3.5K. Don't run the bike much like that or as I said, you can hole a piston. You've been warned.

 

[ann0yed]

Ha ha, I have been warned and I will heed the warning and make sure that doesn't happen. Thanks for the help 5twins!

-jonathan

 

[pamcopete]

annOyed,

Well, there is a relationship between spark advance and idle speed. If you set your idle speed to 1200 RPM with the spark advanced that much, it will stumble and die if you retard the advance. What you have to do is increase the idle speed as you reduce the advance so it idles at 1200 at the same time that the advance is where it should be.

Judging from where your advance is, the engine should be idling at 2500 RPM or so, so set the RPM to 2500 before you reduce the advance. As you reduce the advance, the idle speed will come down.

 

[ann0yed]

This is all new stuff to me but I set the idle to 1200 (or as close as I could get it according to my Acewell speedo/tach which shows idle in bars) and rotated the plate so that the mark on the flywheel was within the F brackets and then revved it up to +3000 to see where the mark ended up and it was a little left of midway between the far left bracket and the left F bracket. That should do it right? Well, I'm about to go find out!

-jonathan

 

[ann0yed]

Ok, now I'm thinking I'm not done. Retard the advance? What? How do you do that? At 3000 is it necessary that the flywheel mark be at that far left hash mark? Oh, wait, when you say "retard the advance" you mean rotate the plate to move the mark on the flywheel as seen in the timing light?

-jonathan

 

[5twins]

The advance unit is made to advance your timing a certain set amount, something like 25° I think. When watched with a timing light, this will make the mark on the rotor move from the "F" area over to that unlabeled slash mark to the far left as you rev the motor to 3-3.5K. Yours only appears to be advancing about half of what it should be. Something may be wrong with your advance unit. I notice you started another thread about how badly your bike runs. Until you solve this timing advance issue, it's not gonna run any better.

 

[ann0yed]

Yes, that photo was taken while I was trying to adjust the timing at idle. I've since got the rotor mark to show up in the "F" area at around 1200rpm but when I rev the bike up to 3000 or thereabouts, the mark is about midway to the far left mark. I gather from what you've written that the mark MUST be all the way over above that far left slash mark at 3000rpm, correct?

-j

 

[5twins]

Yes, full advance occurs about 3000 to 3200 RPMs. Rev it up to about 3500 or so just to be sure you're running it fast enough to achieve full advance.

 

[XSLeo]

When reved up the timing mark should move toward the full advance mark. At about 3200 rpm it should reach the full advance mark but NOT pass the full advance mark. If it goes past the mark then you need to reset the idle timing more retarded, to the right. On my 75 with the Pamco I have the idle timing at the right hand line of the two F lines and it just hits the full advance line at 3200 rpm.

 

[ann0yed]

Great, I will try to do this. Thanks to everyone for the input!

-jonathan