[thstone]

The manual and tip engine harnesses are different.

You will need to swap the engine harness from bad engine (which is wired for a manual transmission) onto the replacement tip engine.

There are also cooling line and vacuum line mod's that need to be made (which are easy to do).

There should be a 4 way "T" and a 3 way "T" cooling hose on the Tip motor. Use the 3 way hose and the "L" shaped hose from the Manual motor.
The vacuum line on the tip at the intake has a 4 way tee. Use the 3 way "T" from the manual motor.

I apologize to who ever originally posted those instructions! I lost the link and so I can't give proper credit.