I have E30 316 4-cyl carb. BMW with 45000km (yes only less than 30000 miles). It was not in use for 7 years, and coolant was changed some three years ago.
Now (I think) I have problem with choke on my carburetor. I got it cleaned (ultrasound) in a local carb shop, and for a while it worked OK.
My problem: I start cold engine, revs go to ~1000 rpm, then after about one minute go up to ~1500 - 1600 rpm. But after five minutes or so rpm starts dropping, so when I stop in traffic its ~400 - 500 rpm, and sometimes just stales.
Since coolant is running trough the carburetor I suspect that choke system may be clogged, since engine runs OK once it's warmed up.
I have Bentley and Haynes manuals for E30, but I found no instructions on how to flush cooling system. I knew where are radiator and engine block drain plugs.
What is the right procedure to flush cooling system?
Let me just note that chemicals for flushing and professionals that can do that job is hard to find (at least I do not knew any) where I am.