Should the Regulator be too Hot to Touch?

[5twins]

The play probably won't hurt anything, you just need to make sure it is advancing only the set amount of degrees it's supposed to. As they wear, the amount they advance grows. There's an easy fix though, read about it here .....

http://www.xs650.com/forum/showthread.php?t=8636

 

[freddy3]

i had a similar problem, the pin that holds the ATU to the shaft came out.

I'm still not clear on which pin you're talking about? Is it the pin in the end of the cam that fits into that small, round spacer with the directional arrow and notches that the advance weights fit into? Or is there another pin behind the advance backplate that can't be seen in any of my photos?
So far, I've only seen the one pin in the end of the cam, which is right where it's supposed to be in the last photo of my set from last night.

and i agree that the weights are being held in place by the ATU's body. i would pry the tabs out slightly to see if that helps, they look to be at too tight an angle, like they've been squeezed in...

I'll check that this evening. If the tabs ARE too close, 2 questions:
1) Can I just fit a flat head screwdriver in between the weight and tab and (gently) pry them out?
2) Is there a spec that details the amount of space between the weight and stopping tab?

beautiful close up pics, btw, freddy,

Thanks.

 

[5twins]

There's another pin behind the advance that you can't see. That's why I've been telling you to take it off. That's the only way to check that pin. Did you do the TDC test I mentioned?

Don't try bending the tabs. It weakens the unit and the tabs break off in short order. Did you check that the advance rod rotates freely? I should correct my earlier post. You can't really grab that little disc, the weights are in the way - grab the 10mm nut that holds it on instead and rotate it that way by hand to check for binding of the rod.

 

[freddy3]

Am I correct that if I find that the engraved line on the backing plate points directly north or south when the crank is at Top Dead Center (the T mark on the stator), that means the pin or key that's behind the backing plate is in the correct position and I do NOT need to remove the screw-thingy and/or backing plate? Is that correct?

There's another pin behind the advance that you can't see.

To be clear, you want me to pry or lever this screw-thingy off (then the advance backing plate should slide off the shaft):

That's why I've been telling you to take it off. That's the only way to check that pin. Did you do the TDC test I mentioned?

I won't be able to get back to the bike (I keep it at a public storage) until this evening and I'll do the TDC test (rotate the crank until the rotor lines up at the T on the stator and check the location of the engraved line on the advance backing plate to see if it is pointing directly north or directly south) then.

Don't try bending the tabs. It weakens the unit and the tabs break off in short order.

If, as some have noted, the tabs are bent (too close to the advance weights), is my only option to replace the backing plate?

Did you check that the advance rod rotates freely?

Yes and it's new, as of last year. (I had a problem with the idle "hanging" when revved and I replaced the advance rod in an effort to fix that - problem turned out to be the advance weight/spring assembly, which I replaced.)

I should correct my earlier post. You can't really grab that little disc, the weights are in the way - grab the 10mm nut that holds it on instead and rotate it that way by hand to check for binding of the rod.

My metric skills are nil. Is the 10mm nut the one that holds the cam shaft in on the advance side? If so, I didn't detect any binding when it turned a couple of times before I removed it yesterday, but I'll certainly re-check it this evening.

 

[freddy3]

Success....well, mostly, but with a slight twist !!

It was a long (HOT....102+ degrees) fight, but I finally got the bike running with the timing--both at idle and at ~3000rpm (via the timing light)--dead-on....well, except for an odd ghost in the left cylinder (more about that below).

But it was only after I reinstalled the notched nut the way it was originally (flange side in) that I was able to get it timed and running. As it turns out, that screw-thingy doesn't come off; the advance backing plate, once levered free, slides over it and off. Once I got the backing plate off I could see the pin behind it and the slot in the rear of the backing plate that that pin fits into. And with the pin in place, the backing plate only fits on one way and, on this bike at least, the engraved line on the backing plate does NOT point due north or due south when the rotor's at TDC.

Also, I cleaned/relubed the advance inner rod and made absolutely sure it rotated like butter and that nothing was binding as I turned it while watching the points move up-and-down as they should. Definitely, no problems with that inner rod.

As I reassembled the advance unit, I made sure that all the moving parts moved freely; and that the weights had sufficient space between them and the stoppers on the backing plate and that they rotated smoothly on their pins and retracted all the way when I pulled them to their maximum deflection point and then let them go.

After everything was re-assembled, I reset the points to .35mm and then began timing the right cylinder with the timing light. It was nearly perfect right-out-of-the-box and the screwdriver indent in the points backing plate (for setting the timing) is now more centralized than it was when the notched nut in the advance unit was installed with the flange facing outwards. So that seems more correct.

Similarly, when I revved the engine to ~3000rpm, the rotor mark now moves properly forward towards the Advance line on the stator. I can't honestly say if it stopped right at the line, but it was close. Definitely, behaving differently than yesterday when the timing mark just sat on the 'F' no matter how much I revved the engine.

The only thing that didn't look right is that when I time the left cylinder, the timing mark on the rotor appears twice, at the same time! That is, I'm seeing two images of that timing mark with the timing light. One appears where it's supposed to be (between the 'F' lines on the stator) and the other image appears just to the right of the right-hand 'T' line. I'm also hearing a slight misfire in the left cylinder, which I think was the original problem I've been having and why I originally said the idle was "slightly rough".

As I kept the timing light running (engine at idle), I noticed that every 4-5 seconds or so, the ghost image would disappear, momentarily, and I'd see a single timing mark dead in the middle of the 'F' lines. So, while there's still something wrong somewhere, I figured the timing isn't gonna get much better than that until I can figure out what's causing that ghosting in the left cylinder with the timing light.

Here are photos of what I saw. Before I began, I set the crank to TDC and checked the orientation of the engraved lines in the advance backing plate and center spacer. As you can see, they're definitely not pointing due north or south:

I ran the crank around again 'til TDC to check the other side. As you can see, the line's rotated 180 degrees, but still not pointing north or south.

Once I got the advance backing plate off, the inner pin obviously hasn't fallen out:

And you can see the cut-out in the rear of the backing plate where that pin resides, so I don't really see how you can possibly install the backing plate incorrectly with that cut-out (for the pin) there:

While I had it out, here's the advance inner rod. You can see the cam at the points end and the pin at the advance unit end. The rod is new (as of late last year) and looked fine, so I just cleaned and relubed it before reinstalling:

In case they're useful, here're a couple of shots of the inside of the cam shaft with the rod removed. From the points side:

From the advance side:

Once I reinstalled the backing plate, I moved the crank to TDC:

....and re-checked the orientation of the engraved line on the backing plate to see if it was now pointing either north or south. As you can see, it's just the way it was when I took it apart:

Here's a photo of the assembled advance with the weights in their normal (closed) position:

Here, I'm gently pushing the weights apart to illustrate the arc of movement. It looks pretty normal, so I think the apparent tight fit from yesterday's photos were just due to the missing cir-clips:

And here's a short video showing the movement of the advance weights while I'm manually turning the advance rod (from the points side) after I got everything back together:
http://triumphpc.com/work/xs2/final.avi

I haven't driven the bike since I got it back together (late, dark and I was too beat), so I'll reserve final judgement for a bit. But, from what I saw just revving it in the parking lot after I finished this evening, I think I'm kinda back where I was a couple of days ago where the engine's running great except for a slight roughness in the idle (likely related to that ghosting I was getting with the timing light when I timed the left cylinder).
Hopefully, if my description of the ghosting sparks someone's thoughts as to what might be causing it, I can finally get this long thread closed and use this heat wave for something productive (Yamaha'ing).

 

[sgallaty]

That 'ghosting' sounds funny to me - i forgot, do you have a single coil (that puts out a + and - ?

Otherwise I'd check the dwell on your left cylinder points, and also check the points for good contact. You said you replaced the condenser.

that faint line sounds like a weak retarded spark that's causing misfires. Bad/loose cable, bad boot, bad ground somewhere from the points forward.

 

[freddy3]

I tried (a number of times) to snap a photo of the ghosting, but all I got was the single mark above the 'F'. I had a friend with me today and he saw it as well.

I've got dual coils and I'll have to wait until the new digital dwell meter arrives (in 2-3 weeks), because my old analogue dwell meter only supports 6- and 8-cylinder engines and when I set the points with it, the engine barely runs (there're a handful of posts within this thread detailing the problem I've had trying to set the points with my current dwell meter) and runs like crap). The points are new (as of Wednesday) and were installed along with a new condenser. Plugs are also new.

It's very weird, but I'm sure you're right about it being something loose or a bad contact or ground somewhere. The question, after I've virtually replaced every component within the charging and ignition systems (some more than once!), is how to locate the source of the ghosting/missing left cylinder?

 

[sgallaty]

Be methodical and thorough. You're almost there, and you've got a pretty good bead on the problem.

 

[5twins]

I told you the threaded thingy doesn't come off, it's the end of the cam. I DID NOT tell you the scribed lines would point north and south at TDC, the pin stub on the plate will. You see on the back of the advance that post or plug above the locating slot to help retain the pin .....

That shows through on the front of the unit as a little nub .....

This little nub should point up or down (north or south) at TDC.

 

[freddy3]

I told you the threaded thingy doesn't come off, it's the end of the cam. I DID NOT tell you the scribed lines would point north and south at TDC, the pin stub on the plate will. You see on the back of the advance that post or plug above the locating slot to help retain the pin .....

You're right. I misread your post. I've been going 'round in circles with all the ignition, charging, advance, etc problems (and remedies) I've running through over the past few weeks....and running back-and-forth to my public storage unit almost daily; and doing all of this troubleshooting/work in 95-100+ degree heat (and surreptitiously - "work on motor vehicles in our parking lot is strictly forbidden"), which has made me a bit foggy on some of the details of this lengthy thread, so please bear with me. My apologies.

Anyway, re the orientation of the pin. This is the orientation of the pin and backing plate now:

Is that close enough to due north or does it need to be dead-on like this:

 

[5twins]

I think you're good because you are actually not on the "T" mark in your pic, you're on the letter "T". TDC is the slash mark just to the right of the letter "T", the one with red paint on it in your pic. Move the rotor mark over to that red painted slash mark and I'll bet the pin does point straight up then.

 

[freddy3]

Good. Pin orientation issue solved.

Any ideas re the remaining problem: slightly rough idle vs the ghosting timing mark readings for the left cylinder (i.e., the timing marks are appearing at two places at the same time on the rotor when viewed with the timing light)?

What I mean by slightly rough idle is that it sounds like one of the cylinders (most likely the left since that's the one that was ghosting with the timing light) is intermittently "missing". Back when this whole thing began, that missing would cause the bike to stall at stop lights. But somewhere along this thread, the stalling improved to the point where the idle's just not smooth and I can hear one of the cylinders intermittently "missing".

 

[5twins]

You might try shimming the end play out of the advance rod. Some of the brand new ones have quite a bit. It can cause the timing marks to jump around if it's excessive.

 

[freddy3]

I've been checking that rod to see if it was loose every time I had it out and there doesn't seem to be any play in it. At least not lengthwise (i.e., it doesn't move in or out when I try to push/pull on it from either end). Is that where the play you're referring to would be?

 

[5twins]

Yes, but you say you have none so ..... I'm not sure what the problem is.

 

[freddy3]

Just wondering... Do you think the (new) points could've been damaged while I was monkeying around with the timing over the past couple days?

 

[sgallaty]

The timing marks appearing twice is curious.

Your next step is to put an oscilloscope with an inductive pickup on the spark plug cable and see what the spark circuit looks like.

I think you may be having spark based misfires.

I know it doesn't make sense with all the new stuff but it almost sounds like you have points that are bouncing (bad contact, debris). The ghosting can happen with a bad condenser too but you've made it clear that this was replaced.

Check resistance on your spark cables through the coils, and move the coils around while doing it.

 

[freddy3]

The timing marks appearing twice is curious.
Your next step is to put an oscilloscope with an inductive pickup on the spark plug cable and see what the spark circuit looks like.

I think I should explain that I'm not an electrical engineer and the only electronic test gear I've got is a Fluke 75 DMM, a Sun inductive timing light and an old (analogue - with needle pointer) tach dwell meter (made for 6- and 8-cylinder engines). I don't have an oscilloscope and wouldn't know how to use one if I did. Sorry..

I think you may be having spark based misfires.
I know it doesn't make sense with all the new stuff but it almost sounds like you have points that are bouncing (bad contact, debris).

Actually, that does make sense. Originally, I thought I might not've gotten the little pin on the back of the points plate into the hole on the timing plate and that might've caused either the points to shift around or be the source of the erratic (ghost) readings I'm seeing in the left cylinder. But I just went over there and double-checked and the pin was in the hole. Just to be sure, though, I removed the left set of points to be sure there wasn't any debris between the point contacts or behind the backplate, but it all looked fine.

The ghosting can happen with a bad condenser too but you've made it clear that this was replaced.

Yes, just a couple days ago.

Check resistance on your spark cables through the coils, and move the coils around while doing it.

Sorry, excuse my naivete again, but do you want me to hook up one lead of my DMM (obviously, set to measure resistance - that part I get) to the metal contact inside the spark plug wire cap (the end that fits onto the spark plug) and the other DMM lead to one of the screws on the left cylinder coil while physically moving the coil around (off the bike)?

 

[sgallaty]

I was thinking it could be good to take the bike to a buddy that's got like an old bear diagnostic machine and have them run a scope on the output side of the plugs.

This is a good read :

http://books.google.com/books?id=otgDAAAAMBAJ&lpg=PP35&pg=PA35#v=onepage&q&f=false

I'm not suggesting that to be difficult, I'm saying that you have a pretty interesting problem and you could benefit from having a knowledgeable guy look at the wave form. You MAY have a faulty coil, or bad boot or even a fouled plug but the waveform will help you diagnose that.

I know it seems like an odd suggestion, but there's a right tool for the job and when the job gets unusual so does the tool =)

 

[freddy3]

sgallaty: At this point, if I had such a friend with the appropriate test gear (or even spare garage space where I can concentrate without having to look over my shoulder!), I'd be there. In fact, I probably would've taken that route right from the beginning, were it an option. But, unfortunately, I've got what I've got and that's why I'm here asking all of these stupid questions. One way or the other, I'll get the bike fixed (always have), but it helps to have a 2nd (or 3rd) opinion when up against weird problems or stuff I'm not real familiar with.
Again, my apologies to anyone who feels I'm wasting the forum's time. That certainly hasn't been my intention. I'm just trying to return an historically reliable bike back to the road.