ran,died, dead

[mckee]

ok guys and gals. I got an issue that's driving me crazy right now. I have a freshly rebuilt 79xs650 with mikes xs pma, a pamco, makuni vm34 carbs, and im running a sparks capacitor with no battery. I just put the bike together about a month agoin and set all the necessary times and clearances. the bike fired first kick. ran great for about two weeks. ( running for me to tune carbs and just putts up and down the street).a few days ago I rode it down the street and it sputtered and died when I let off the throttle. now it will not start at all. if you try to kick it it kicks back and backfires like a cannon. any ideas would be help full.

 

[XSLeo]

When you installed the Pamco and PMA did you hook just the ignition to a battery and the PMA to the rest of the bike?
You need to do this to test the PMA for proper voltage output. Sometimes a PMA can go nuts and send 20+ volt spikes through the system. Some times at idle the volts are ok but drop at higher rpms. Both of these things can effect how it runs.
I might suggest you hook just the ignition to a battery. Leave the rest of electrics as is. Now try to start the bike. If it runs ok then your PMA has issues.
If it starts and runs ok check the voltage at the cap. Is it ok?
Leo

 

[hard_y_rd]

Check timing. Sounds like the locating pin may of went awol.

 

[mckee]

the timing is ok and all the voltage is ok and it has great nice blue spark

 

[retiredgentleman]

Make an inspection of the ATU. Are all parts secure? Are the weights fully collapsed with the engine off? Do the weights snap back smartly, if you open them with your fingers? Was the ATU shaft lubricated?

 

[pamcopete]

the timing is ok and all the voltage is ok and it has great nice blue spark

OK. Did you try what XSLeo suggested?

 

[mckee]

Yea I tried that and it stayed the same. I reconnected everything and got it to run twice for about 30 seconds then it will not start at all. I pulled the pamco apart and reassembled everything again and lubed the fly weights and everything. Kicked it and it didn't run just back fired when I kicked it and hats it. Never had this much trouble getting an engine to run

 

[pamcopete]

Yea I tried that and it stayed the same. I reconnected everything and got it to run twice for about 30 seconds then it will not start at all. I pulled the pamco apart and reassembled everything again and lubed the fly weights and everything. Kicked it and it didn't run just back fired when I kicked it and hats it. Never had this much trouble getting an engine to run

Did you try what hard_y_rd suggested? There are three locating pins. One on each end of the advance rod and the third one that locates the advancer:

 

[Brassneck]

This may sound overly obvious, but you have enough gas in the tank and have switched to prime/reserve to make sure you're not too low on fuel to use the "on" setting?

 

[Kathos]

When I had this problem, turned out the nut holding my pamco plate to the advance rod came loose so my timing was off.
Just throwing that out there.

 

[mckee]

Pamcopete) my advance rod did not have the pins it is just a threaded shaft straight to the bearing. and the tank is full and the nut on mine actually backed off to hense the reason the removed it and reassembled. but i dont have any pins other than the one on the left side of the engine that keys the pamco to the shaft.

 

[figure8]

I would go back through the install directions for the Pamco.. There should be two pins on the right side as well.

 

[pamcopete]

Pamcopete) my advance rod did not have the pins it is just a threaded shaft straight to the bearing. and the tank is full and the nut on mine actually backed off to hense the reason the removed it and reassembled. but i dont have any pins other than the one on the left side of the engine that keys the pamco to the shaft.

There are three pins needed. One on each end of the advance shaft and the third one to locate the advancer to the cam shaft on the right hand side. You need all three of these pins.