Ok, so swapped all the bits off the mrs old engine to the new one... On the new one the crank sensor had been cut, so set about replacing it with the original.. They have an Allen key holding them in.. Took it out the old engine and put it in the new one.. Wouldn't screw in.. And upon further investigation the Threadded part of the screw is a different diameter and the crank sensor out the new engine (with the cut wire) was a square sensor with a locating pin and the one out of our old engine was round with no locating pin.. I've got the old sensor in the new engine now but just wondering if it will read ok?? Anyone know the differences? They both have three wires.. Hope you can help