I have a 1976 KZ900 with original electronics (points).
The bike runs pretty darn good, however, I get a strange sound under certain conditions that I am going to do my best to describe... but I'm sure I won't be able to do a very good job.
When you are at lower RPMS and especially under a slight load (maybe around 4k rpm) and you are not really accelerating hard, just maintaining .. I get this sucking/popping sound. Let me try to describe it.
It almost sounds like a click, but there is air involved somehow.. It might be coming from the carbs. If I let off the throttle or give it a bunch more throttle it quits right away.
I can't decide if its coming from the points or the carbs.. It might even be a lean condition on the carbs at that spot in the throttle. But I am no expert by any means.
I was thinking of taking the carbs off first and seeing what the jets, needles and settings are and start there, but other than that.. it runs ok. The only other spot is when you are really getting on the throttle.. around 6-7k rpm, it bobbles a bit and then after that, it screams... So I assume thats something to do with the needle or position of the needles.
Your thoughts are welcomed!