1978 70 hp poor speed/power--need wiring diagram of switch box

[barry soxman]

I am having a problem with my 1978 70 hp merc that sounds similar an earlier posting. I bought it "as is" for a 16.5' sylvan fiberglass bowrider. I checked the compression and all cylinders were ~165psi. I first had no power and very poor runability and I was afraid it was just too small for the boat. After some investigation I found my fuel pump was bad. After rebuilding the fuel pump, It appeared to run OK but the boat would come up on plane -it just plowed water at ~12mph. I suspected the prop and changed from a 14p to 12p --better but with 3 adults it still woundn't plane-just plow to ~14mph. With just my son and I on board it will acually plane and go ~26mph. I do not have a tac but the motor doesn't sound like it out of range for rpms. After some checking I found a formula for predicting boat speed and with the weight estimates I had it suggested a speed of ~31-32mph. I worked the numbers around and the formula said a 48hp motor would give me the speed I was getting. Thats when I read about an earlier post about the switch box causing problems.I looked over my motor a little better. In looking over the switch box II fould the orange wire removed from the 2nd position marked orange and connected with the blue wire on the 3rd position marked blue.. The post for the orange wire appears to be dead. I bought a repair manual on CD from E-bay but it is worthless. I t has no wire diagrams-none! If you or anyone could spare a copy of the wiring diagram so I can find were the orange wire goes and if it being paired up with the blue wire would have anything to do with the motors lack of power I wiould be very thankful. It idles smooth and appears to run good when it can rev up. I have power tilt with 1 cylinder leaking slightly so although it wouldn't hold position completely I was able to move it to help with bringing the nose down.

My e-mail is bsox56@verizon.net

thanks,
Barry