It is possible fit the chip one pin out of alignment - which _shouldnt_ blow it up.
Alternatively, 1 pin of the chip is bent or broken too short and not making contact.
If you want to send it to me I can check that its ok at work (electronics engineer) and poss still make a copy if its a broken pin.
I've run my 748 with 3 different chips and with different power commander maps with different chips.
If its too lean the performance goes off, and you will know that all is not right !
The engine will run (poorly to badly) with a lean mixture but because it also runs hotter, you really musnt run it lean for any length of time or your piston will let you know it doesnt like it
