the chokes also pull air through those hoses under the diaphragm, so maybe it's a choke airflow interaction?
I didn't kown that and it made me think.
Last winter I serviced the carbs on my bike successfully. The bike runs better, starts better,...
There's just one thing that's changed since I mounted the carbs again and that's the choke.
At first: I pulled the choke all the way when starting, the bike started and revved up to +/- 3000 rpm, then I released the choke till the 'click' halfway and the revs dropped to +/- 2000 rpm. At that time I started the ride and after a few hunderd meters I turned the choke off.
Now: when i pulled the choke completely the bike still revs to +/- 3000 rpm but stays there even after I pull the choke back to the halfway click. From there on the revs drop to 2000 rpm when I pull the choke halfway towards the off-position.
So since I serviced the carbs there is no change anymore between full choke and halfway choke.
before: choke 1/1:3000rpm, choke 1/2: 2000rpm, choke 0/1: 1200rpm
after: choke 1/1:3000rpm, choke 1/2: 3000rpm, choke 1/4: 2000rpm, choke 0/1: 1200rpm
The only thing I changed is that I removed the air-filters in the diaphragm lines. I should put some new ones in but I haven't done that yet. ( I could not find the OEM ones and I'm not sure I can replace them with simple inline fuel filters)
Could the absence of these air filters cause the change with the choke?
(there's no problem with the choke cable or the choke on the carbs, all works flawlessly)