Should the Regulator be too Hot to Touch?

[sgallaty]

No man, not at all - and that's not what I am saying.

Even if you had a buddy who could do it for you, coming here and asking questions is valid.

We're here because we want to spend our time here =)

That's not at all what I am after - I was actually hoping you would find an oscope so I could see the output for clues.

 

[freddy3]

sgallaty: I got that.

I just took the bike for a short drive and it's got a pretty severe flat spot on acceleration. Kinda like turbo lag (for those of you with old turbo-driven cars), but it's never done that before. And I get the feeling it's also running hot, which it's never done before. So I've gotta re-do the timing.

Do you know if I can use the dwell meter (it has alligator clips) to check when the points open?

I've been using the Fluke 75 DMM (it has a continuity checker that beeps when there's continuity and stops when there isn't!), but it only has metal tips (no way to clip the leads onto anything). So I've gotta hold both leads while I'm rotating the crank with the other hand, which is a bit difficult.

With all the weird problems, I'm re-reading the timing section of the OEM Yamaha Service Manual and thinking that I must've gotten something wrong, early on. Somehow, I got it in my head that I was supposed to set everything based on the F and T (as opposed to the lines around them!). Maybe I got the point (relative to the stator lines) where the points open wrong or something like that?? It's gotta be something simple because virtually everything's new and I can't believe a new part would have the same weird problem I began with.

So, this evening, when the temps drop down below 100+ (presuming it doesn't rain), I'm going back and starting over. I want to reset the points to be sure they're opening at the right time and I'm guessing I'll then need to re-gap the points, which will then require resetting the timing.
Ugh!

 

[Gordon]

Not a dwell meter, but a diode checker on your meter should be good. What is even better is a test light. Clip the lead to the point set your checking, turn on the key, and rotate the engine with a wrench. Plug wire's grounded, of course. When the point's 'open', the light will come 'on'. it is the same as using the strobe light, just not running. Oh, forgot, ground the probe end of the test lite.
Have you tried to synchronize the carb's at all. Use the 'dead cylinder method' in the tech section. They are pretty close using that method, and fairly easy operation. There is a whole lot of info there. Read it all a couple time's, so you understand what they are telling you. Once you get all this maintenance work done a few time's, it will be alot easier, and you will gather some 'old school' knowledge on engine operation. This is all basic stuff, and once you 'get it', you will see what I am saying. Also, every single one of us started this same way, by asking alot of question's. I, fortunately, was a high school (trade school) instructor for a couple of years, so, finding an explanation you understand is easier for me. I remember being such a pain in the ass when I was young and starting out, but the one's who taught me were the same way with me, very patient..

 

[sgallaty]

the sequence goes like this :

Points close
primary coil builds up pontential
shaft rotates.. time passes
points open
primary coil field collapses
secondary coil is charged by collapsing field
spark plug sparks

so, when you set your timing with the timing light, that is the result of that sequence, and the timing you have to adjust for.

you need to get some clips for your tester so you can test continuity on the points to see when they close and open

 

[freddy3]

Gentlemen (and I'm including the RetiredGentleman in this announcement):
I'm done!

There's no need to draw this already ridiculously overlong thread out any further, because....it's fixed! Yes, I said "fixed", as in problem(s) solved! Oh, and without any qualifications.

She's idling (actually, pur-r-r-r-ring's probably a more apt descriptor) at ~1100 and runs like a dream. I took her out for a short drive in the country and then back through a (nearly) stop-and-go main city street with lots of stoplights and she never missed a beat.

As it turned out, starting over was probably the only way I'd ever've gotten to this point. Somehow, although I've done this dozens of times over the 36+ years I've owned this bike (until I lost my garage/house a dozen years ago, I used to run through the entire tune-up process (including timing) at the beginning of every riding season), I missed a small paragraph in the Service Manual explaining that you need to manually gap the points to .4mm before continuing with the rest of the points adjustments/timing process.

As soon as I read that (and it finally dawned on me that I'd done that many times before) and proceeded to gap 'em correctly, all the other settings/parameters fell into place without a hitch. Since I was following the "A" plan in the manual (which times the bike statically), I can't verify whether the left cylinder's still "ghosting", but my gut (and the final results) tells me it isn't.

Anyway, I want to thank all of you who stuck with me through this for your help and support. I wish I had half your knowledge and experience.

At the end of the season, I've gotta replace the clutch (yes, it's the original from '72), so you can probably guess that I'll be posting another thread asking more questions.
Thanks again, Everyone, and have a (safe) ride on me!

 

[sgallaty]

Mission accomplished, happy to have been a help - if a help I was.

 

[freddy3]

Mission accomplished, happy to have been a help - if a help I was.

Yes. And much obliged, sgallaty.

 

[5twins]

Once you get your 2 cylinder dwell meter, you should never have to stick a feeler gauge in your points again. I gap them by eye close enough so the bike will start then dial them in exactly with the meter.

 

[xjwmx]

Somebody has the Hunter Thompson look down for real.

 

[freddy3]

Once you get your 2 cylinder dwell meter, you should never have to stick a feeler gauge in your points again. I gap them by eye close enough so the bike will start then dial them in exactly with the meter.

I'm definitely going give it a try as soon as it arrives. But it's nice to see it as a convenience instead of a necessity (or the last hope).

Somebody has the Hunter Thompson look down for real.

I don't know about that, especially, now that I've got a huge smile on my face! And thanks again!

 

[xjwmx]

It was interesting. Glad you're running.

 

[jack82]

Hi there,......Thought I'd jump on this old thread as I have a similar problem to the OP.

I'm getting my 79 Special back on the road after 20 years sitting in the corner of the shed. The bike is stock standard. Cleaned the carbs,fresh fuel,new battery, started second kick and idled like a good thing, .

While checking the lights, turn signals etc I noticed the green resistor attached to the regulator gets too hot to touch within 20 seconds of the ignition key being turned on.(this is without the bike running)
Any ideas on where to start tracking down this problem? …...Cheer's Jack.

 

[2XSive]

Those old mechanical regulators need to go. You can easily replace that, along with what I guess is the original rectifier, for less than $30, all in. There's plenty of threads on here how to do it along with the exact parts you'll need. Just do a search for reg/rec mod.

 

[jack82]

Those old mechanical regulators need to go. You can easily replace that, along with what I guess is the original rectifier, for less than $30, all in. There's plenty of threads on here how to do it along with the exact parts you'll need. Just do a search for reg/rec mod.

Thanks mate,......will do a bit of searching.