[jkv45]

Originally Posted by nocturncal

I had a hard starting problem for a while, chalked it up to dirty carbs/being cold originally.

Whenever I started the bike, it would sputter/have a hard time getting going.

After having the carbs cleaned, the bike ran perfect! Ride it around for a day, then today the sputtering returned! The first couple of pistons firings sounded super weak. But all it took was a second of winding the throttle or pulling the choke to full on startup to get the engine going, then perfect idling, no idle troubles for today.

Took a look at the carbs and one of the intake rubbers from the airbox to the carb had unseated itself. So I reseated em and now the bike starts up without a hitch, no weak piston firing during the first couple of cycles.

Does my fix sound plausible? I did this with the bike not cold, but not totally warmed up yet so I'm wondering if there's something else that could be going on.

Also trying to understand how a vacuum leak could lead to hard starting

That's not really a vacuum leak at that point. Being unseated from the boot to the airbox may certainly disrupt airflow into the carb and cause issues, but there's no vacuum on that side of the carb.

A vacuum leak can affect starting as well as running at any RPM.