BANG BANG stall...

So I cleaned up the jets, emulsion tubes, and choke tube thingies, as well as took a look at my timing chain tensioner. Got it all back together, everything seemed fine. Bike was running better, though I think a bit rich, as I couldn't use full choke by any stretch anymore. There was a bit of garbage in the jets and emulsion tubes.

Well, I'm going down 85 at about 60mph, about 10-15 minutes into this trip, the bike decides to let out a couple of loud bangs, I lose power, pull in on the clutch, and it stalls. Won't restart, every once in awhile when I tried to start it, it would let out a bang(backfire or afterfire or something?). There were a few times when it kind of sounded like (while cranking) something was underwater.

So, what the hell happened?

 

Did you loose spark?? sounds like your pulse coil might have taken a dump. Will it start up when cold? I had a problem that anytime after 15 minutes or so the pulse coils would heat up and refuse to work. If I were you I would see if the bike starts then ride around the block for 20 minutes or so until the bike dies. If and when it dies again check for spark, if no spark then the pulse coil is a possibility.

 

I'll take a look at that tomorrow. There were a few times when I cranked it, that it ALMOST started. It would start to turn over as I let off the start button. But it just wouldn't catch.

 

This is a symptom of a weak battery, due to any number of causes.......

What happens is that as the starter is being engaged, it gobbles up battery voltage. As soon as the start button is released, you now have full battery voltage available TO THE IGNITION CIRCUIT (including the pick-ups, the TCI, and especially the coils), and in that instant when you release the starter button, the coils get enough voltage to produce an adequate spark while the motor is still (by inertia) turning over. If everything is in a great state of tune, the bike will normally kick over. If not, you get what you describe.........

Test the battery voltage WHILE THE STARTER IS ENGAGED (a voltmeter across the + and - terminals of the battrey is all that's needed). It should remain above 9.8 volts (I believe that's the spec). If it drops below that level while the starter is active, then that's the "problem", and the cause of that problem must be determined and remedied.

 

Any more thoughts on what the initial problem is?

 

If you had your chain tensioner out you might want to double check that the cam timing is correct. If you did not get the chain tight enough it could have jumped a tooth or 2. Worse case is that it did jump and now you have bent valves and a plug firing whilst the exahust vales are open or bent open. Best case is that the timing is off, reset the cams to there proper marks and hope for the best. Easy way to check for bent valves is a compression test if it was running well before and now has no comp on 1 or more cyls good bet is that you have indeed done damage and i'm very sorry to be the bearer of bad news.

 

I had my old GS pull the same act on me years back. I sat in the middle of the freeway for 15 minutes before I realised I had inadvertently hit the kill switch. Might be the issue for you, might not... Let's hope it is something as simple as that.