79 xs650 Special - No Spark... But 12v. help?

dhx78

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Hello everyone
im somewhat newer here as far as posting, i usually just try to so research without posting and bothering anyone... but ive come to a dead stand still.
recently i picked up a 79 xs650special.. itd been sittin in a garage since 1987, 1yr longer then ive been alive lol. anyways the bike was given to me under the condition i hadda get it outta the garage by myself, proved to be pretty easy.. anyways, ive went through the bike..cleaned/checked everything i kno how. short list...
-new battery
-swapped Coils (from my 78)
-New Plugs
-Cleaned Gas tank
-Replaced carbs with my 78's carbs (lines, hoses, air filters)
-soaked cylinders with oil/trans fluid (not much, jus to lube them abit)
-Cleaned Points, Connectors, Checked Fuses
My valves, pistons both free... i have 12v at the coils and wires.
everywhere ive checked, 12v. the problem... i have no spark from the wire to the plug.
i have 12v up to my points... im thinking my problem is there tho.. but im just not sure. perhaps i havent cleaned them good enough or properly... but im not sure where to go from here, ive been in and outta the tech section... and thinking maybe i needa try adjusting the valves, cam and timing next.. just wondering if anyone had any pointers.. im somewhat new to worken on bikes but i kno my basic's. this is the 3rd XS ive owned and only one i havent had runnin after acouple days!

76' xs360
78' xs650
79' xs650 special
 
Something similar happened to me when I bought my '73 Honda CB450. Power everywhere but no spark. I cleaned the points. Still no joy. Finally, I removed the points and saw that they had a film on them of some sort from sitting for years. I had to take the points apart so I could get a larger file on the points. Filed the "film" off until they were bright and clean. Bike fired right up. Then, of course, I installed my new PAMCO ignition and tossed the points in the trash. I just wanted to be sure the engine would run before trying my newly designed PAMCO ! :D

So, you have to take the points apart in order to realy get them clean...:thumbsup:
 
Yup, I'd definitely be looking at the points as my first suspect. Make sure they're shiny and clean, wires from coils aren't shorted to anything and THEIR connections are shiny and clean, and the gap is correct.

Trying a known good set of plugs would be next.

After that would be the coils and wires which are pretty easy to swap.
 
Thanks for the quick responses guys. i was gonna pull the points apart to file them down ait better.. but wasnt sure if i should lol. im not to familiar with the points system, so wasnt to hastey on taking stuff apart. but tomorrow ima give it a try, i got brand new plugs and the coils are fairly new.. so ima clean'em, gap'em and hope for fire! im really interested in the pamco system.. that might be the route i go once i kno the bike is in good running order. thanks again, ill post my results.
 
Yeah points is an old technology BUT it has it's little tricks which are getting harder to find, now that even us old guys are forgetting the fine points (groan). In the day every shade tree mechanic could grab a matchbook and set the points blindfolded. (Where you going to find a matchbook these days, Ebay?)
Oh here is a bit of useful info LOL The wire from the points should be going back and forth from 12V to 0V as the engine cranks. Condensers often go bad even just sitting. Propane torch and wire brush the spark plugs frequently, a little oil from the top end lube, will bleed off voltage before they can spark the gap. Be vary careful not to leave the bike sit with the ignition on not running, it only takes a little time to smoke a coil or burn the contacts. It can go either way, I have spent major time getting a points system back operating. Then the other day a points bike that had been laying out in the weeds so long we had to torch the drive chain off it to move it and the bike had great spark and ran as soon as I hot wired the coils to the battery. I keep a little harness with an on off switch to bypass all the stock harness wire meandering and get known good voltage to the coils. a tail light or turn signal bulb clipped to the point wire should go on and off brightly as you crank the motor, a quick are the points working right test.
 
WooooHooo! thats how imma start this post. i cant thank everyone enough, that has put their info and knownledge on this site. big thanks to pamcopete and everyone who replied. im glad to say not only did i get spark after a good cleaning to the points but i got fire! i got everything clean and gaps checked... put her all back together and hit the starter once.. and Poof! she let a small backfire out. i cranked her abit then decided to kick 'er to save the battery and starter some strain.. after bout 20 kicks she fired up and ran. i ran it about 10min then shut it off and changed the oil again. let it sit for another 20min.. hit the starter and it fired right up, no hesitation. i cant believe how smooth it seemed to be running after 25yrs sitting in a garage! Thanks again guys, Youll be seeing me around! ill keep updated with pictures on this build and the re-build on my 78' xs650 chopper. im aiming at my brakes next, luckly that is my field so it should go smooth.. gotta love the specials, disc front&rear :)
 
a tail light or turn signal bulb clipped to the point wire should go on and off brightly as you crank the motor, a quick are the points working right test.

I'm doing battle with my recently acquired 78/79 XS. No spark at the plugs but the battery is new and putting out 12.6v. I tried the 12V light trick and got the following results:

When light was clipped to the orange wire it stays on even when motor was cranked. Light was dim, checked it with volt meter and it was about 9.8v

When test light was clipped to the gray wire, it didinot light at all, even when motor cranked.

Help appreciated! Thanks in advance.
 
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I'm doing battle with my recently acquired 78/79 XS. No spark at the plugs but the battery is new and putting out 12.6v. I tried the 12V light trick and got the following results:

When light was clipped to the orange wire it stays on even when motor was cranked. Light was dim, checked it with volt meter and it was about 9.8v

When test light was clipped to the gray wire, it didinot light at all, even when motor cranked.

Help appreciated! Thanks in advance.

Use your VOM to measure voltage,until you find where the voltage drop is occuring. Measure after the main fuse, then measure after the ignition switch, then after the ignition fuse, and finally after the kill switch (same point electrically as the coil primary). Any or all of these can rob you of voltage.

The stock fuse holders (with glass fuses) are infamous for corroding and causing high resistance and the resulting voltage drop. If your bike has them, replace asap with new automotive blade type fuse holders.
 
Pabeye, I might wager your problem is similar to dhx78. Being a 78-79, you have points and they need attention.
By the way the bike is either a 78 or 79 not both. Use your frame and engine numbers to id the year. There is a good thread on this in the XS650 tech section.
Leo
 
By the way the bike is either a 78 or 79 not both. Use your frame and engine numbers to id the year. There is a good thread on this in the XS650 tech section.

Hey Leo Thanks for the "heads up"........the sticker on the frame says 9/78...the title is 1979.........I would guess the frame sticker is the more accurate.

I'm still doing battle.....have started looking at all the wiring starting from the battery and working from there.........some VERY funky readings on the VOM. I'm trying to get an understanding of what is going on.........:)
 
Just like cars, the new model year begins production in the fall of the previous year. You have a '79 model.
 
I like points. they don't cost sh*t, are reliable, and don't leave me stranded anywhere. a now and then tuneup with plugs barely makes 20 bucks.
 
As 5twins said the production year doesn't coincide with the model year. The production year starts in August and ends in July. As in Aug 78 to July 79 are 79's.
This is shown on some of the vin to year charts.
Leo
 
One small step........I spent a couple of hours replacing the points and condenser and CAREFULLY adjusting the point gap........
IMG_4493_zpsfee3a748.jpg


GUESS WHAT! I got spark on both sides!........

Will wait for another day to dump in some fuel and see if the old beastie starts up.........fingers crossed!
 
I assume as you adjusted the points gap you also adjusted the timing. Changing the gap also changes the timing. So after adjusting the gap you need to set the timing.
Leo
 
Thanks Leo....when I adjusted the gap I just tried to eye ball the high spot on the lobe......not easy, in fact I asked the Mrs to help. I did know that there is a relationship between the timing and the points. Way back in the memory banks I had a strobe timing light for some cars ....on my 67 Vee Dub I used used a 12v bulb in a socket grounded to the engine which was enough. That knowledge base and the tools are long gone. I guess there is a thread some where on the board that describes how to do timing. I'll try to find it.

NOW, for the NEWS.....It's ALIVE!! I actually got the beast to run today using a home made testy bottle. She will only start by kicking though......even though the starter does turn the engine.maybe not fast enough? (battery is at 12,6V)


NOW the bad news......SERIOUS smoke coming out of the right side exhaust, along with lots of oil. Being the pessimist I am I figure the rings are shot on that side (I no longer own a compression tester) I was wondering if there is possible another , less $$ reason for this. I might also mention that a lot of smoke exits the breather hoses as I throttle up more on the right side than the left. The first start up video is here:

http://s271.photobucket.com/user/paladdo/media/MVI_4494-iPhone_zps47e0a755.mp4.html

Here is the still:

IMG_4501_zps0ac0f766.jpg


IMG_4497_zps48d53103.jpg
 
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...SERIOUS smoke coming out of the right side exhaust, along with lots of oil. Being the pessimist I am I figure the rings are shot on that side (I no longer own a compression tester) I was wondering if there is possible another , less $$ reason for this. I might also mention that a lot of smoke exits the breather hoses as I throttle up more on the right side than the left....

Pretty much indicates bad rings on that side. There is the rare and outside chance that they're stuck. A little marvel mystery oil in that cylinder, some cycling and waiting, might free-up. A compression test before and after adding the oil would help to confirm.

Other scenarios include oil seepage in headgasket (retorque head), and leaky valve guide seals (smokes alot after startup, then backs off). But, the breather blowby (when that side is throttled) pretty much confirms rings.

If you could borescope that cylinder, and it looks fine, then stuck rings would be my best guess...
 
Thanks TM........here is a little more information I forgot to post that might help you smart guys diagnose the problem. There was little smoke when the bike first starts, it seems to get worse as the bike runs. In addition to the smoke there is quite a bit of oil exiting the pipe, and finally when I pulled the plug id did not seem to be fouled by oil. I'm perplexed...thanks in advance.......
 
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