Motor won't crank

[RichRab]

2002 Mercruiser 5.0 MPI 260 alpha 1 gen 2. A couple of years ago one of the tabs that holds a screw for dist cap broke so I used flat washers to secure cap. All good until the motor started misfiring at high rpm over the weekend. Idled fine and ok at low speed and I made it back to dock. When I checked things I saw the cap lifted up so I figured I would change the cap since I used an automotive cap when in a hurry to winterize at end of season. When I cranked motor it sounded like the wires were crossed and motor would not crank. Made a loud sound like the motor was locking up and it ruined the drive on the starter. I have changed many caps and did one wire at a time. Triple checked and all is correct. Is is possible that when motor was misfiring that the motor loaded up with gas and even though it idled that the motor is locking up?

 

[Bt Doctur]

pulling the sparkplugs is one way to check for a hydrolock condition

 

[RichRab]

I pulled one plug and it was dry. Just looking for ideas before I get back down next weekend. Thanks

 

[Bt Doctur]

You need to remove ALL of them

 

[RichRab]

Update......got a new starter and one bolt was out. Optimistism side of me hoped that bolt fell out. We know reality. I got a magnet and confirmed the bolt had broken--no part of bolt exposed. Tried a few ideas like angled picks and trying to unscrew using broken bolt and not enough room or view using an angled drill and a reverse drill bit-none of which worked. Motor being pulled to repair.

 

[Bt Doctur]

broken starter bolts are from :
hydro-lock
wrong bolts, too long of bolts.
When the holes are cleaned thread a starter bolt in place and tighten bolt. Accurately measure from the block to the bolt head. Measure starter flange, it must be less than bolt length

 

[RichRab]

Bolts are probably from 2002. One bolt that was still in is slightly bent from boing all the work. Broken bolt was corroded like it broken for a long time. I think they were loose.

 

[RichRab]

I mean doing all the work.

 

[RichRab]

Update.... water in cylinders 4 and 6. Manifolds good. 800 hrs on motor all salt water. Made choice of new complete motor. Piece of mind well worth the cost. Done deal and back to the water. Thanks.