Yes in two ways. My bike had both issues when i got it up and running in the fall, it took quite a while to get everything diagnosed and sorted
1. Advancer shaft is bent: if the shaft has more than 0.010" of runout it can cause jitter and make it very hard to time and cause the timing to jump around. If this is the case it should be carefully true'd to under 0.003" runout and things should work alot better.
2. Weak advancer springs: if the advancer springs are weak it will cause the advancer to start advancing to early and can cause a bad idle as the timing bounces around. To diagnose this you need to use a timing light and carefully watch the timing marks and advancer weights at idle. and as you give it a little gas the timing should be on the F mark up to 1200-1500 rpm then you should start seeing the weights fly out and the timing advance from the F mark by 2500rpm it should be at full advance. If its bouncing around and moving at idle or below 1200 then the springs have stretched or are weak. The easiest solution is to remove the advancer, then remove the springs and bend the spring hooks in a little about 0.020" to 0.040" and try it on the bike again you may have to mess with it a little to get it advancing properly again.
