Yamaha 40 de-tuned to 35 need help!

Hello, I have a 1984 Yamaha 35 which is really a de-tuned Yamaha 40LN. The way they de-tune the motors is by not allowing the throttle to fully open, it opens 1/2 to 2/3 the way on the 35 . The accelerator cam for the 40 to fully opens, the part: CAM ACCEL. 6H4-41213-40-00, is no longer available from Yamaha which is a double bummer as it was under $15.00, the cheapest 5 hp gain ever! Does anyone happen to have or know where I can get the cam? Or does anyone know of a way to add to the lobe of this cam to make it fully open? One last thing, will I need to change the timing too? Thanks for any and all help.