Hey guys, We have a 502 with a side mount Whipple rebuilt with new aluminum heads, extrude honed intake and a whole lot of other stuff. We built the motor in our shop and Eddie from Young Performance walked us through the entire build. (Awesome Dude by the way) The motor was running fine until we broke a valve spring. Replaced all the springs, retainers etc., and put it back together. Started up in our shop, ran for an extended amount of time turning on and off for about an hour.Next day started up again at the shop and all was fine. Got to the lake put in the water and NOTHING HAPPENS. It turns over good but no spark. Replaced the ICM in the distributor, replaced the coil and still no spark. Any one have any idea as to what could be our problem. Any and all comments will be much appreciated.

Msd box

Hey chuckels, thanks for the reply. Are you saying add an MSD box or ? It does not have one at present. It's a MEFI 4 system

Figured it had one , I go through em every other month

You need to get the ignition troubleshooting flow chart from a Merc manual and run through it. Very simple and will help you narrow down the problem in a hurry.

KILL SWITCH , NEUTRAL SAFTEY SWITCH ! most comon 2 !

Thanks Griff I'll try to get my hands on a manual today.

Sounds like a pick up coil in the distributor.
Allen

Simple test check for power on + side of coil when turn ign on.. If thats good put on neg side and crank over see if test light flashes.. if it stays on no flash then the pickup no work if you dont have power on + side then you have to chase wire up to ign switch or ck switch