An MK-17 has been lent to me to look at. It is in great shape. It's only problem is that starting and setting a clean run is difficult. The intake cross section is too large. I have to 'finger choke' it to start.

http://www.youtube.com/watch?v=v_DAU-cMQ5s

I wish to remove the "big bore" red anodised venturi insert, and put in the alternative "narrow bore" beige anodised insert.

WIth the NVA removed, the red insert will not budge. I am thinking of using heat and if that fails solvents.

Has anyone changed the venturi insert? If so, how is this most easily accomplished?