variable timing issues

[aschattke]

The bike was running rough and not using its full range of rpms (it wouldnt get up above about 5k). We determined it was the variable timing and replaced the vacuum part ($90). That didnt fix it so we checked the carbs to make sure we had vacuum. We indeed did. I already replaced the rubber intake boots so i know its not those. When I clamp the vacuum line running to the variable timing I can get it to run right (sometimes). I need help on fixing this problem.

I am not a mechanic and only understand this much because I have a good friend. We are stuck and cant figure out why my variable timing is not working properly. I was told that this device can be switched from a vacuum controlled to a mechanically controled. Is this possible and would this fix my problems?

The bike is an 81' xs 11

[crazy steve]

Where do you have the vacuum line connected? If it's on one of the carb boots, that's the problem; it's supposed to hook to the number two carb, which has a semi-ported vacuum connection just for this. Look right in front of the idle screw for this...

[motoman]

pull the timing cover again, remove the vacuum advance so there's no interference. Aside from the wires being attached the vacuum advance mechanism should freely spin like a lazy-susan. If ANY resistance rotating, it has gotten a bit gummy on the rotating ball bearings. This WILL keep the vacuum advance from working properly.......don't ask how I know. Who-ever told you what they did IS clueless! 81 models, the mechanical advance is done in the TCI module under the seat(electronically), still using ported vacuum for vacuum assisted advance. Also that TCI module should have a gold/orange tag on it showing: TYPE TID14-04 under that is 4RO-10. The ONLY year using this module. Previous year models used the 2H7 module and will work but will be sluggish revving and do NOT incorporate the mechanical advance electronically. That is done at crank assembly with weights and springs. Hope that helps.