I purchased a 71 r75/5 about 6 months ago and have been working and riding it on and off during that time. Recently bought a mikunis carb conversion and I am having an issue with the throttle returning to closed. Enough time has lapsed that I can't remember if I always had to force the throttle closed. I order a new throttle cam gear and throttle tube and it still does not want to return on it's own power. I should mention that for some reason the new throttle tube does not fit so I am still using the old one. Think they may have sent an incorrect part. The cables are new and don't seem to bind. When I pull the cable end it seems to move back with sufficient power. I have a 2 cable system. Any pointers on setting this up send what to check would be great.