Help! Bike started running rough, and appears to have a dead cylinder. WTF!!!

[spent]

Okay, so I put my project on hold, and scored a running XS pretty cheap. Things were all good for a day or two, and then- out of the blue- shitsville. I was running pretty good when I put it away, but when I fired it up the next day it was running rough as hell. Now, one pipe is way cooler than the other, it backfires out the carbs, and falls flat on its ass when I put it in gear. My guess would be timing, but I'm new to the XS, so I'm not sure.

Any input would be greatly appreciated. Its got a PMA, a pamco, and Mikunis. I'm totally new to the PMA/pamco deal, so I have no idea where to begin.

 

[TurboFarviknugn]

Check voltage. Pamco MUST have 12 volts in order to run properly, IF it dont have full 12 volts mine ran just like you are describing.

 

[visimpact]

Probably a carb issue. I had some of the same symptoms with my latest bike. I took the carbs apart and cleaned them up really good and put them back on and it fixed all of the issues.

 

[Yourboychrisc]

Sounds electrical to me.

 

[spent]

Thanks guys. I'm still at a loss on this one. My first guess was carbs, but with them running so good, and then shitting out so completely less than 24hrs later, I started to lean towards electrical.

As for the Pamco, what could be causing it to run under 12v? Forgive my ignorance, but I'm dying to ride this thing, and I'm all thumbs when it comes to electrical, so any and all feedback would be greatly appreciated. I'm going to assume that I'm having ignition/wiring issues, before I tear into the carbs.

 

[burns]

Check voltage. Pamco MUST have 12 volts in order to run properly, IF it dont have full 12 volts mine ran just like you are describing.

Nope. A PAMCO will run on a 6volt lantern battery.

 

[burns]

check the basics.
Are both plug caps securely attached to the plugs?
are you getting fuel to both carbs?

 

[TurboFarviknugn]

Sorry i ment to say PMA (perm magnetic alt) if so equiped. We ALL have ignorant moments, hell i wired mine wrong 2k miles ago, and just figured it out tonight ! I know if it aint charging correctly it drains the battery and it will run like crap IF at all.

 

[spent]

Thanks guys. I'm getting fuel, plug wires seem kosher. The battery was pretty well drained, and once it charged a bit she seemed to run a little better. So I'm guessing that it the PMA.

Turbo- what exactly was wired wrong on yours? I'm thinking I may be having the same problem you had.

 

[TurboFarviknugn]

Had a scorched connector due to me straying from the wiring diagram, thus putting too much resistance on the system to charge. Look for open shorts, chafed wires. How old is your battery ?

 

[TurboFarviknugn]

Have the battery checked at vato zone. Put a charger on it over night then take a test run, if it still runs like crap with a charged battery prob barking up the wrong tree.

 

[burns]

Have the battery checked at vato zone. Put a charger on it over night then take a test run, if it still runs like crap with a charged battery prob barking up the wrong tree.

right-0, but get out your multi-meter and check the voltage at the battery poles with the motor running at various RPM. It needs to be over 12 and under 15 everywhere.

 

[5twins]

My carbs ingested some crap a couple seasons ago. The problem presented just as yours is. It ran fine the previous time I rode it and ran bad the next.

 

[TurboFarviknugn]

I am not sure if this is possible with your setup but in the vw world the pic carbs suffer from glogged jets very often so every so often to clear mine out i remove the pod filters take the rngine up to about 3 k rpm then place my palm over one carb thus sucking the jets out clean of small debris. Just a thought.

 

[Take Warning15]

Would it say anything about which cylinder was the dead one? I've got all sorts of problems like this on mine. I have a cold left cyl., won't take throttle, but it will idle with choke. I'm going to clean the carbs good tomorrow and will let you know how I make out with mine

 

[spent]

Damn, had to put the bike on hold for a while because of work, but tried to fire it again today and its running worse than ever. I'm spraying some carb cleaner in both of them, and its on the charger now, so we'll see where we go from here. I'm hoping its not wired wrong: electrical is my lifelong nemesis.

 

[spent]

I'm getting frustrated. Cleaned out my carbs, started to chase down wiring to see if anything looked queer- just keeps getting worse. Last night I kicked and kicked and all I got was the occasional puff of smoke out of the carbs. I'm thinking this is ignition (when it was off the batt. charger and running the lights were piss-weak). My fabricating skills far outstrip my diagnostic abilities, so I took a break and made up a new fender strut/light mount. But now I'm still here scratching my head. I think now I need to find a good wiring diagram.

 

[coughing skunk]

Are you sure the plugs are good? Change em out and see what happens

 

[spent]

Couldn't hurt to try new plugs- never hurts to rule out the simple shit before diving in deeper. I'll pick some up when I run into town later.

 

[coughing skunk]

Yeah, I only suggested it cause I had the same thing happen and my plugs looked fine and had a spark outside of the cylinder. After spending hours trying figure out what was happening I replaced the plugs and voila.