Re: Motor stopped when in idle and wont turn over now. Help Please!!!!!!
Several things could have happened. You won't know for sure until you get into it. Start by looking at external portions of the rotating assembly such as flywheel and lower unit. Pull the lower unit off and try turning the engine a full rotation. If you still can't then eliminate the lower unit as the problem. If you can, then you've found the problem. Check in, under and around the flywheel for anything loose, missing or broken. I saw a Merc once that had a 3/4" stainless steel screw under the flywheel that was causing it to lock up. No one knew how it got there.
If everything is good externally, you're next step is to pull the heads and watch the pistons. If one isn't moving you can safely bet it's a broken rod or wrist pin issue. If the pistons are all moving but suddenly stop then something is getting hung. Rotate it back then forward and watch each piston. The one that's causing the problem will cant slightly when it hangs. The problem might be a wristpin, a stuck or broken ring or even a broken reed that got ingested. I've even seen a broked rod cap bolt do it. In any case, you've got an internal problem.
It doesn't always mean a complete tear down. I've replaced pistons and rods on Mercs and never split the cases. You might be able to also. As long as there aren't any rod's sticking out of the side of the case or holes you can usually fix it. A hole in a case is often repairable also and cyliders can be re-sleeved if badly damaged or welded and re-bored. They even make an epoxy that can be used to fix cylinder walls but it was actually designed to restrucure valve porting in 4 stroke motors. It works really well but a lot of guys don't believe it because they think of it as plastic.
