rebuild

[konkreteredneck]

Trashed ny 150 a couple of weeks ago, to many RPM's, no 3 came out through the intake. Its a 75 Mercury and parts are getting hard to find. Found a new intake and crankshaft, honed all cyl,and evrything goes back together nice. Sit P/H back on boat, finally get motor fired back up, notice that it is dumping raw gas out of exhaust, pull plug wire on no# 5 and RPM's jump about 1000, pull plug wire 6 and jumps another 1000. Pull a comp test on it and none off the cyl's differ more than 2 pounds. All cyl. firing in corret order. Was told to check carbs, pulled them off went through them, all floats are sitting correctly. Then came across an old CDI magaxine that had a trouble shooting guide in it which reads that inline engines with internal exhaust plates if engine speeds up when you remove a plug wire , the internal exhaust plate is more than likely warped. Pulled power head back off, and into the exhaust, not sure how to check the plate, used a straight line and it looks fine, the gaskets looked good. Now this is where I stand, not sure what to do next, any advice would be greatly appreciated