No spark on "bad decision" bike

79josh81

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Hey everyone I'm new here so bare with me...

So, I got this crazy idea a couple months ago that I wanted to build a bobber out of a xs650 even though I had no prior experience working on motorcycles but plenty with working on cars and I consider myself an easy learner when it comes to mechanical things. This "idea" of a bobber build was cool, but everything after that has been a pain in my ass. So I purchased a 1979 xs650 a few days ago. I spoke with the old guy who was selling it and he was a bike enthusiast and told me that it ran when he put it away 5 years ago. He drained the gas tank and, in his words, "stored the bike the right way". Being how old he was, he wasn't interested in getting the bike running for me because there was no battery in it and no fuel. Cosmetically, the bike is in really good shape. Long story short, I trusted him (mostly because he was so old) that the bike ran when he put it away (and it may have) and I bought the bike.

I got it home, put a battery in it, poured some gas in....and....the problems started here. The carbs flooded and over filled the float bowls and pissed gas out through the air filters. One of the fuel lines from one of the petcocks was cracked which gas poured out of. And both petcocks leaked around where they seal to the tank.
So i pulled the tank, petcocks, replaced the carb fuel lines, removed the carbs and cleaned them (I think the bowls overflowed because the float pins were gummed up), and put everything back together and poured some gas in for round 2.

The petcocks still leaked at the tank a little (I knew they still would) but the carbs didn't overfill. I tried to start the bike and it would crank but would not fire. At this point I'm ready to kick an old guys ass but I'm trying to live different these days. So I pull a spark plug and figure out that I also have no spark...on either side. FML. Electrical stuff. I hate electrical stuff. Mostly because I'll usually source out electrical problems because again...I hate electrical stuff. The bike DOES have power everywhere else as far as I can tell. Just no spark.

So anyways, I google and try to figure things out and this is what I've tried:
-New spark plugs and set gap
-replaced all fuses
-opened the "points" (which I'm completely new to) and checked conditon and made sure the gap was right, lightly filed and cleaned the points and everything looked good and in spec as far as I could tell
-tried to do all of the multimeter testing for the coils but honestly, I don't understand that stuff. I know the resistance on the primary is supposed to be 3.9 OHM +-10% and my reading was 4.9 on both sides (not sure if it being that high matters). The resistance on the secondary is 7.8 OHM which it's supposed to be 7 to 8. The only thing was that I got that secondary reading when I put the multimeter positive into the plug wire with the plug cap off (straight into the wire like I've read). *******When I put the spark plug connector back on the wire (the 90 degree connector boot that actually connects to the spark plug) and put the multimeter positive into that to test the secondary, the resistance was like 16 to 17 OHM. Shouldn't it still be 7.8 OHM even when using the 90 degree spark plug boot instead of plugging directly into the spark plug wire? ******

Honestly, I need some experience here to help me out. I know I probably don't sound like i know a whole lot as far as diagnosing no spark on an xs650....and that's because I don't. I already feel like an idiot for trusting this guy and buying this bike so I'm only looking for constructive comments and help in figuring this out. From what I've read while browsing here, people know their xs650 s**t on here.
 
One thing to learn from this is everything runs when put away. It doesnt mean it will run now with gas and a battery at the press of a button. A detail go thru list should be gone over on the bike to ready it to run or even turn over without causing damage. You will get the info you need. Post a pic of your ride...we all like to see these awesome bikes in any state it is in! Oh and welcome!
 
If stock, or proper aftermarket, your spark plug caps are "resistor caps", maybe 5,000 ohm resistors inside them. If you're not ready to do/learn/understand electrical tests and repairs, give it up now, because it never ends. Don't blame the PO because your problems are super normal for a bike that has sat for that long, no matter how it was stored. Good start on the fuel problems, just got to do it ALL.

WELCOME TO THE FORUM, ask any questions, read, search, it can be fun.

Scott
 
If stock, or proper aftermarket, your spark plug caps are "resistor caps", maybe 5,000 ohm resistors inside them. If you're not ready to do/learn/understand electrical tests and repairs, give it up now, because it never ends. Don't blame the PO because your problems are super normal for a bike that has sat for that long, no matter how it was stored. Good start on the fuel problems, just got to do it ALL.

WELCOME TO THE FORUM, ask any questions, read, search, it can be fun.

Scott

Yeah I hear you and I'm willing to learn the electrical stuff. Everyone starts somewhere when they try to get into this stuff. As far as the resistor caps, should I replace them? Could that be causing any problems?
 
79josh81, here's a couple of threads from the 'TECH' forum that you should go through to help you start getting acquainted with your new bike.

Tons of great info in these.

http://www.xs650.com/threads/guide-...checklist-for-the-condition-of-your-find.367/

http://www.xs650.com/threads/bike-wont-start-running-rough.390/

Enjoy the process, and welcome!

Oh, and as has already been said, post pics, we like pics. :)

Thanks man. I appreciate pointing me in a direction to help me out. I'll get a pic too sooner or later when it's not tore half apart.
 
I’m pleased to announce that “Bad Decision” has spark! I went through the majority of the electrical system for the ignition and cleaned up all the contacts. I cleaned out the kill switch which had, what I assumed to be, brake fluid all dried inside of it. Then I went to work on the stock fuse block, completely removed it and installed a new block, changed all the connectors, and put in all new fuses. I almost pissed myself from happiness when I hit the start button and saw I had spark on both sides. Wasn’t expecting at all to get spark after doing that stuff but figured I should try just to make sure.

Once my new petcocks come I’m going to install them and try to start this thing again so we’ll see what happens. Thanks for all the help fellas.
 
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