All of the Sportster series were kinda large. If you think the .45 is big, wait until you see the .65
TimC is correct about the glo plug also. Mine seem to like the K+B long w/idle bar. I have had the best luck with 5% Sig fuel with 20% all castor.
If you need parts, they are still available from Mecoa
http://www.mecoa.com/