I'm just a hillbilly, but put this in your vacuum line, on your regular carb, and no more slaming. It is an ordinary fish tank valve. Just adjust as needed. Worked for me and just $1.00.
I could have used one of those years ago...
tried everything to slow the vacuum down..
nail in the vacuum hose.. etc
None really worked successfully
LEE in Australia
this is great, worked for me.
Well, Mine has been slamming when attached to the New H30/31 Solex-Brosol carby but it worked although slightly slowly with the hose disconnected... but found I had the hose on the wrong port.. lol
changed the port to the lower one, and it Now works great... lol
I'll have to take a pic of it.. lol
Lee in Australia