Mercruiser 4.3LX Carb Adjusting
 

I need to adjust the carburetor for my 94 4.3lx with thunderbolt ignition and the 4 barrel carb. My question is I thought I read at one time I need to put the ignition module into learning mode by putting it to ground. Is this true? Thanks

Does anyone know if that is true that I need to ground the one wire? I would like to adjust this today Thanks!

is it thunderbolt iv or v?
if v, you must ground the puple/white wire on the ignition harness(this locks the timing)... set the timing, adjust the idle screws for the smoothest idle, and set the idle speed screw for 650 rpm, the of course unground the wire.

I didn't even know there was 2 different types. I have the iv so I guess I could adjust it without having to ground anything or is there still something else I have to do? I'm still used to the old points and condesor lol.. just curious what is the difference between Iv and v? Thanks

does your engine have a spark knock sensor threaded into a boss on the side of the block? if so, its a v... if not, its a iv, and you just adjust the carb as normally done

Where on the side of the block would the sensor be? Down near the spark plugs or up more on top by the valve cover? I looked but I may have missed it. Also on the black cover above the flame arester it says iv, but I certainly would like to double check and make sure the previous owner didn't get a different cover

I had to do a carb rebuild and I'm in the process of doing that but the problem is I can't separate the carb in half. I removed the 8 screws on top of the car, and I also gently put a thin puty knife between the two halfs to try and lose the gasket as well as pry it open but it seems like something is holding it back. Did I miss a step or a bolt? Thanks

Just wondering if anyone knows of anything else that I need to do in order to separate the top? Thanks