i have a '87 tw that starts good, idles great , carbs rebuilt, but when it warms up it stutters , backfires and barks, and has trouble idling . if i let it cool down overnight it starts all over. could it be coils or cdi? my neighbour has the same tw , his runs great unless he lets it sit for 3 or 4 days than it wont start? if he runs it every day every thing is fine. what could be wrong. he won't let me try his cdi because he thinks i may blow his cdi with my bike problems.