Does anyone have any suggestions for a 1990 Yamaha control box? I am able to still use, but when I get to about 3/4 throttle it pops in like its in the neutral position and will not move. I can still move forward/ more throttle. So when I back off I have to squease the release and it slides as normal. It is most likely a cam? I was told and have seen a diagram with all the parts, it would be difficult to take apart and work on. I have two quotes, both at about $500. The control box is model 703 and cost $350. Any help out there? Thanks