Bike had not been ridden for 7 years? Your carbs must be dead, then. We all rebuild carbs here from time to time. And problems with carbs appear from nowhere.
So the bike idles good when hot? I start riding with choke closing litle by little as engine warming up. Dont close it just by marks in the temp gauge.
I turn down choke immediately to 1200 rpm when it starts, and start riding without proper warming. Then gradually turn choke off. That works in CA. There is also a "sweet" point on the choke curve - google it.
And absolutely nessesary to sync carbs. Tool cost about $40.
They say it is not going into carbs, good enough for me. I will clean it from time to time. Fire Medic scared me with all those tests that i can not do myself, and there is no mech around to work on vmax. Thanks Sean for a good news.
Are you asking me? That not a foam:) That is gui watery-oily crap that accumulated through crankcase breather hose - My guess, for years. I did not saw it because it is hidden beneath the cover.
So you took carbs from bike yourself and put them back? You have manuals? Do you have manometers for synch? I will go through this crap when i receive my carbs back. No mechanics around want to work on old bikes especially vmax.
Why don't you take bike to Dan? Try to synchronize carbs. Mine was popping and run rough after winter for 2 months until it "died" on the road. Starting was fine with open choke . Look what i found in airbox.
Mine started doing something like this. Did you took carbs off the bike yourself and put them back? If so, double check all connections - that was pain in the butt for me just take it off. I am waiting to receive them back from Captain Kyle.