No power over 3000RPM - Engine trouble - XS2 1972 XS650

...I have installed a volt-meter, my battery charges, etc. Floats around 12 when not running to up to 13 when running...

That, plus your runtime degradation, makes me think failing rotor.
Best to do the charging system checkup.
And/or, another quick test:

Charge up the battery.
Replace the fuse, use a 10 amp.
Disconnect the regulator.
Ride it around.
If it runs better, and doesn't blow the fuse, suspect the rotor.

If not,

Charge up the battery.
Replace the fuse, use a 10 amp.
Disconnect the regulator and rectifier.
Ride it around.
If it runs better, and doesn't blow the fuse, suspect the rectifier.

If not,

You've got your work cut out for you.
Time to thoroughly inspect the harness...
 
It's definitely an "over center" geometry. This would take some descriptive tutorials to explain that...
Ever wonder why a 747's landing gear doesn't collapse on the ground with about a million pounds sitting on them? Over center locks. The harder you push, the more locked they become. Glad someone gets it.
 
Starting to look like it's the first option (rotor). What do I do?

Jose'

That, plus your runtime degradation, makes me think failing rotor.
Best to do the charging system checkup.
And/or, another quick test:

Charge up the battery.
Replace the fuse, use a 10 amp.
Disconnect the regulator.
Ride it around.
If it runs better, and doesn't blow the fuse, suspect the rotor.

If not,

Charge up the battery.
Replace the fuse, use a 10 amp.
Disconnect the regulator and rectifier.
Ride it around.
If it runs better, and doesn't blow the fuse, suspect the rectifier.

If not,

You've got your work cut out for you.
Time to thoroughly inspect the harness...
 
Starting to look like it's the first option (rotor). What do I do?

Jose'
Before you spend a ton of money... verify the rotor is bad. Use an ohm meter and check resistance across the rotor brush rings. Should be above 5 ohms, any less is bad. If that's what is causing the fuse to blow, you're probably looking at less than 1- 1.5 ohms. You really need to check that before throwing money at it. Even if you planned on spending the big bucks on a PMG upgrade, you STILL need to find the source of the short that's blowing the fuse first.
EDIT: Forgot to mention... also check both brush rings to ground. They should be open.
 
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Yep, found this http://www.bikermetric.com/techtips-2-the-xs650-charging-system/ and already on it - if I could only find my meter....

Before you spend a ton of money... verify the rotor is bad. Use an ohm meter and check resistance across the rotor brush rings. Should be above 5 ohms, any less is bad. If that's what is causing the fuse to blow, you're probably looking at less than 1- 1.5 ohms. You really need to check that before throwing money at it. Even if you planned on spending the big bucks on a PMG upgrade, you STILL need to find the source of the short that's blowing the fuse first.
EDIT: Forgot to mention... also check both brush rings to ground. They should be open.
 
Yep, found this http://www.bikermetric.com/techtips-2-the-xs650-charging-system/ and already on it - if I could only find my meter....

xs650LA, I'm gonna put you on the spot here, not so that information shouldn't be x referenced, as it should be because we need to be confident information we are getting is right.............But..........Why look for the information elsewhere before looking on here........in that link it states the rotor has to be 5.5 ohms or it is shot........Do some research on that information or you could be throwing away a good rotor............those guys are more inclined to be PMA advocates.

Using the search on here, with the question "testing rotor"........ http://www.xs650.com/search/7426992/?q=testing+rotor&o=relevance

Tech menu under "Electrical"....... How-To: Diagnose charging system problems (charging system guide) Explanation of the electrical systems on the XS650

It has also been found that a rewound rotor can Ohm out a 4 Oms and be working perfectly. This is due to the size of the winding's. Stock rotors do not Ohm that low...........i am not going to tell you what it should be, the information is in your manual and in the links i have posted............
 
Oops, did not know that researching the net was a xs650 faux pas. I tend to look around for as many information sources as I can...

Speaking of PMA, I might go that route after all I've read. My advance is shot, now if my rotor is shot too, pretty much beats the purpose of trying to fix things. I haven't had time to find my meter (long story), but I did run some testing as per the indications of @TwoManyXS1Bs. And here is what I have to report:

1. At home I let it rest since Sunday and today I finally got a break from work where I could play with this stuff. I did not even put the battery on tender since Sunday. I put a 10 amp fuse in (my rig only has one fuse..yeah...nice). Keep in mind, the bike was as it was out of the tow. So I turn all systems on and nothing blows. The battery reads 12.1. Not going down too fast (my headlight is always on), so it seems all fine. Ok....that's strange.
2. So being all's good, I kick it and the bike starts with a 10 amp fuse just fine. Revv it up and runs for a while and it's fine. I did not take if for a ride. But I shut it off, and it's fine fine. Great.
3. A while later I go back and I try the same, systems on, kick it, runs, rev rev rev, put some choke on to warm it up, get too confident and the engine dies on me. And as that happens, I hear the pop in the exhaust and BAM, the fuse goes out. In short the fuse blew just as the bike died out.
4. Fuse is burned, so I am like...ok, WTF. I turn everything off and I put another 10 amp fuse in. Turn the key and lights are on, battery seems fine so I turn the handlebar ignition lever to On...BAM fuse out.
5. Ok, so now I am curious, somewhere there is a lot of power buildup. After it ran for a while I saw about 12.5W in my battery so that one has plenty of juice (it seems). As per @TwoManyXS1Bs recommended I unplug the regulator, pop another 10amp in and BAM it dies as soon as I turn the key on... strange...
6. Just for kicks I unplug the rectifier too, put another 10 amp in, turn the key and BAM, another fuse out...

I haven't had the chance to look for my meter, so I haven't really had a reading. But what do you folks think this is? I even unhooked all the connections, went around and checked all cables. It looks messy but I don't see anything that jumps at me... the brushes seem fine, etc.

So here's where I am at. I HATE the wiring on that thing and all the components are old - as in original ones. Seems like my advance unit is shot, maybe my rotor is shot... seems like I'll have to redo (or thoroughly re-check) my wiring. So I am wondering, should I not just bite the bullet, save up 600 or so bucks, get a PMA (I know, heresy :)) get an e-advance unit, and in the process get myself a decent fuse box, a decent schematic, and redo the whole thing? I know it's going to be a pain but I always thought at some point I have to redo the wiring on this sucker (it's spaghetti and it's supper mikey moused, as in... wire colors are all over the place, spliced all over, etc).... thoughts? Advice?




xs650LA, I'm gonna put you on the spot here, not so that information shouldn't be x referenced, as it should be because we need to be confident information we are getting is right.............But..........Why look for the information elsewhere before looking on here........in that link it states the rotor has to be 5.5 ohms or it is shot........Do some research on that information or you could be throwing away a good rotor............those guys are more inclined to be PMA advocates.

Using the search on here, with the question "testing rotor"........ http://www.xs650.com/search/7426992/?q=testing+rotor&o=relevance

Tech menu under "Electrical"....... How-To: Diagnose charging system problems (charging system guide) Explanation of the electrical systems on the XS650

It has also been found that a rewound rotor can Ohm out a 4 Oms and be working perfectly. This is due to the size of the winding's. Stock rotors do not Ohm that low...........i am not going to tell you what it should be, the information is in your manual and in the links i have posted............
 
If you disconnected the Reg. and rectifier, you just eliminated the whole charging system. Regulator feeds the rotor. Stator feeds the rectifier.So none of that is the problem.

The fact that you turned your kill switch on and the fuse blew tells me it's in the ignition system. Could be a shorted coil, condensers... and because you had the points out of it, it's possible they could be intermittently shorting out. Try disconnecting the hot wire to the coils and see what happens. Then backtrack and disconnect the condensers and look at the points and make sure they're not touching metal they shouldn't. Judging from the pics, I'm still suspicious of the harness though... If I had to guess, the coil is ok till it warms up then shorts out. But that's just a guess.
 
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Yep, I agree it's not the charging system. I went back and unplugged it all for sure. I also rechecked the whole assembly (brushes, etc), not looking like that's the problem. Oh-boy am I going through fuses like it's going out of style... anyway, one thing is strange here. All fuses up to 30 blow up the same way. Only with a 30amp fuse in does it seem ok. But I haven't started it and ran it long enough (did not have enough time). But 30amps?!!?!

I actually ordered new coils the other day from MikesXS, should I put those in? Not sure what condensers you are referring to. Is that the starter condenser? I also took a good long look at all the wiring, I cant really tell what is going on because of the mess, but I did not see anything that looks like it's blatantly shorting. However, my electrical engineering study days are long gone. Is it possible a condenser is building up enough amps that it is the culprit? Seems like that's what you are saying... if so, it makes sense, I run it for a while and the condenser builds up until it gets charged up and then BAM all fuses get a 30+ amp charge when I turn things on. This would make sense. MY guess is that the condenser would then slowly release charge and the next day or so, when I go back, it all works fine even with a 10amp fuse...until...the condenser charges up and then it's blowing fuses all over again. Does this make sense?

But yeah, it's def not the charging system.... now is it the ignition or the starter?. My guess now is for the ignition system. after I wrote the paragraph above I quickly went to look under my tank and yep, there are two condensers there just below the tank close to the coils and above the engine...maybe one of those suckers is faulty? Still, the faulty condenser would not behave like this by going up to 30+ amps would it?

Cheers, thanks for all the help so far, and pardon my ignorance about all this if what I said above made absolutely no sense :)


If you disconnected the Reg. and rectifier, you just eliminated the whole charging system. Regulator feeds the rotor. Stator feeds the rectifier.So none of that is the problem.

The fact that you turned your kill switch on and the fuse blew tells me it's in the ignition system. Could be a shorted coil, condensers... and because you had the points out of it, it's possible they could be intermittently shorting out. Try disconnecting the hot wire to the coils and see what happens. Then backtrack and disconnect the condensers and look at the points and make sure they're not touching metal they shouldn't. Judging from the pics, I'm still suspicious of the harness though... If I had to guess, the coil is ok till it warms up then shorts out. But that's just a guess.
 
Hi xs650OLA,
you know the random ads they throw onto the bottom of your screen trying to sell you on better windows or whatever?
On the bottom of this page and ONLY on this page there's an ad from Standard Magneto.
Do you suppose the Motorcycle Gods are sending you a message?
 
Only with a 30amp fuse in does it seem ok. But I haven't started it and ran it long enough (did not have enough time). But 30amps?!!?!
These bikes came with a MAIN fuse rated at 20 amp. If you only have one, make it a 20. A 30 just allows more current than the system was designed for. Remove the 30 before you burn something else up like the wiring! What you are looking for is a short to ground somewhere, that's what blows fuses. A condenser shorted to ground, the coil shorted to ground, the points, the wiring.... something in the ign. circuit is shorting to ground. That's what you're looking for. That's best done with a meter.
 
So here is an update. I disconnected the charging system as I had mentioned before. And I also replaced the Coils with MikesXS new ones. I then proceeded to take out all the zip ties and painstakingly went over every wire and every connection. I even put tape around connections I thought might have a chance to touch the frame or something (remember, I have a spaghetti harness...). In any case, I then plopped a 20amp fuse in and started the bike...

First thing. Something must have been off with my coils. With the new ones the bike revvs HIGH. Like the RPMs in neutral are much higher. I changed nothing on the carbs or anywhere else since the bike started giving me this electrical issue. So not sure but something is more spiffy now with the new coils.

Second, the bike starts fine. Did it several times with the starter engine, etc. BUT after 3 or 4 times of starting it and stopping, etc...the FUSE blew up... and then it just keeps on blowing up. I don't think it was the sparks. So now I am thinking this might be my points (?!) how can it be that it runs so well and then it craps. Then for a while it just blows every fuse. But I swear, I do nothing to it other than put a new fuse and turn the key and then the kill switch to on...and it blows. But if I wait a few days, do absolutely nothing, and plop a new fuse...it starts...until a while after running when I shut it off...it blows. What happens when the engine stops? It seems to be that when the engine stops thats when the fuse blows....

I'm dogged on figuring this out. Even though I bit the bullet and ordered Hugh's Charging and Ignition systems and also a bunch of stuff to redo the wiring from scratch. I've always wanted to do the wiring and my goal is to get this bike to a condition I can ride it with certainty I will make it back home after say 20 or 30 miles trip. Everybody I have asked has told me to upgrade to a new charging system and a new electronic ignition. I am happy I managed to learn to do it with the points system and learned a lot, but my knowledge will do me little if this thing needs a nudge every so often when I ride it and I get stranded without tools... Anyway, that's my next challenge, new electric pretty much everything :) but I am still going to figure out first what is messing this up before I put all the new stuff in. I have to! Help is appreciated either way :)
 
Let it warm up till the fuse starts blowing, then disconnect the condensers and see if that stops the fuse from blowing. At least you've eliminated the coils as the problem...

Condensers shorting out are extremely rare, but it does happen on occasion.
 
Wow............................92 posts and you are still struggling. That's a bad move to buy an aftermarket PMA and ignition from HHB. Those are poor quality Chinese parts. Your stock Japanese parts are high quality.

I notice you are very reluctant to use a VOM, after that has been suggested by several members.
You have been getting a lot of good advice, but you're not listening to the advice. You are going around in circles and solving nothing.

You have an electrical problem (fuse blowing). There is only one way to solve that problem. You must use a VOM and a wiring diagram and spend lots of time measuring resistance of the various circuits. You have only been 1 month, which is nothing. These old bikes could take 6 months or maybe a years to sort things out. By buying new expensive parts is the worst thing you can do at this point.........................its like flushing money down the toilet. Only after you have identified the real problem, is it wise to buy new parts.

Have you measured the resistance of your alternator rotor from slip ring to slip ring, and from one slip ring to the rotor frame.? As soon a the fuse blows, you should immediately be measuring resistance, as the intermittent short circuit may only occur for a short span of time.

Stop buying expensive parts until you sort things out. If you don't have the ability to sort this out, you should try to find a knowledgeable person in your neighbourhood to help you. Old bikes are not suitable for everyone.
 
LOL, i've been working on this sucker for 3+ years, so I hear ya.

I've been measuring with a VOM (Voltmeter) and I can't seem to find anything at all. I even tried disconnecting as much as i could of anything (lights, switches, etc). BTW, can say it's likely NOT the condenser either @JimD54 - I just went and did like you said, I put a fuse in (15A) blew it, took out all the wires to the condenser, put another fuse in, same thing... I'm starting to think this is Points related as you suggested earlier. Just not able to figure out where...I've been avoiding tinkering with the points after fretting so much to get them and the timing right...but I guess I might have to.

On that note @retiredgentleman I agree to a certain degree on the figuring out before adding new. But if I am redoing ALL of the electrical, it's really pointless and just for my own education - and at that, only while I am still having fun with it. However, my bike's wiring is a Mikey Mouse job and was never good. A "knowledgeable" guy did a re-wiring for me but because I was tight in budget he banged it together to make it work. And...he used the old original (?) wirings that look pretty damn bad (some dry, some are cracked, a lot of splicing where it's just increasing the wire length, although all those look properly soldered, etc). So my plan is to not only put in new parts, but also do it well from scratch and simpler, so there are less failure points. Besides, If I build it from scratch I'm bound to get to know it in and out.

As for Hug's stuff. Man don't say that... I fretted about this and did a lot of research. I asked around, read lots of forums etc. A lot of folks swear by it and say it's the best around. Plus Hugh is known for stellar customer support, and from what I could tell the difference between his and others was maybe 50 or 80 bucks and I will gladly pay that to have better instructions and some dedicated help. But, back to my struggle. I think I have pretty much eliminated the charging system as being part of the problem. So I am replacing it because mine is old and I want to further slim down my build with less and less bulky components.

All that said. I bought a bike that was almost stock and modded it already quite a bit. That's to say, I am not a purist :) I like the old with the new, that is why I built the light bucket with the inserted digital meter in it...although, that meter by Dakota has already failed due to vibration and I have a feeling the one they sent me (for free and 2 years later, a perk of using US made and being friendly) is looking not so good either due to vibration. I appreciate your preference but I'm simply more interested in getting this to a reliable state and of good quality. The old stuff is great but it's 45 years old... and hardly will be cheap to replace, and likely will break too.




Wow............................92 posts and you are still struggling. That's a bad move to buy an aftermarket PMA and ignition from HHB. Those are poor quality Chinese parts. Your stock Japanese parts are high quality.

I notice you are very reluctant to use a VOM, after that has been suggested by several members.
You have been getting a lot of good advice, but you're not listening to the advice. You are going around in circles and solving nothing.

You have an electrical problem (fuse blowing). There is only one way to solve that problem. You must use a VOM and a wiring diagram and spend lots of time measuring resistance of the various circuits. You have only been 1 month, which is nothing. These old bikes could take 6 months or maybe a years to sort things out. By buying new expensive parts is the worst thing you can do at this point.........................its like flushing money down the toilet. Only after you have identified the real problem, is it wise to buy new parts.

Have you measured the resistance of your alternator rotor from slip ring to slip ring, and from one slip ring to the rotor frame.? As soon a the fuse blows, you should immediately be measuring resistance, as the intermittent short circuit may only occur for a short span of time.

Stop buying expensive parts until you sort things out. If you don't have the ability to sort this out, you should try to find a knowledgeable person in your neighbourhood to help you. Old bikes are not suitable for everyone.
 
Yep, at some point I found my meter and found this post too. Those pictures have been my guide for more than a few hours...I did this when I checked all the connections and wires and took out (almost) all of the zip ties and swapped the coils. I just don't see it. As I said earlier, I am thinking there is something in the points. I disconnected all of the charging system and almost all of the indicators, lights etc and this thing still happens... when I click the key I see a spike (what blows the fuse). It's probably something to do with the ignition system, because if I have the bike on it's all good. Only when I turn power by moving the kill switch from off to on does the fuse blow... so there is something shorting along my ignition route (no?). I also replaced the coils and now did a test on the condenser and nothing. So I am moving downstream to the Points because honestly I'm kind of down to that :) Could be something else, but what else gets power when one switches from off to on in the kill switch? Might it be the starter? Its strange since I don't touch it and the fuse blows the first time only when I turn the bike off. Which leads me to think...might this be the kill switch that is shorting and I will be laughing for the fool I am :) when I test it, seems fine though....


Stop running power through your loom and do a continuity test on the whole bike. This will isolate and pinpoint your problem area. .................your are not doing any good except to the fuse manufacturers and their profits.

Continuity test http://www.xs650.com/threads/continuity-testing-made-easy.49917/#post-513643
 
:) I did that. I understand the concept of resistance, or the need for lack thereof for continuity testing. I followed your example on that post... so far, continuity for the charging part of the system seems just fine. But I was by no means as thorough as you were in that post... I did not do all connections and if I got a slight reading I did not go and clean the connection or replace it with a new one like you did...

Still, I'll keep going.

There should be no power on when doing continuity testing. Disconnect the battery.
 
Carving out the salient points.

...I am thinking there is something in the points.

Only when I turn power by moving the kill switch from off to on does the fuse blow... so there is something shorting along my ignition route (no?).

...test on the condenser and nothing.

...So I am moving downstream to the Points

...might this be the kill switch ....

The points and condensers are on the grounding side of the coils. Current has to go thru the coils first before getting to those. Besides, the points function is to ground that side anyway.

Your problem is somewhere between the kill switch (including the kill switch), and the coils, and the safety relay (including the safety relay). That's the only place where grounding can produce enuff current to blow a fuse...
 
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