Help.... 1986 force 125hp

[cairngorms]

I recently picked up 1986 125hp force (not a good looker) so I pretty much new a deal of work would be required. However, when we took the plugs out and turned the flywheel by hand we could get only 270 degrees of rotation (in neutral) and then a sudden mechanical sounding stop, almost like putting a screw driver through a rotating sproket. we traced this to the lower cylinder and by slowly moving the flywheel backwards and forwards whatever was causing the the crank to lock loosened and then we could rotate the flywheel through a full 360 degrees. When you placed your finger over the plug opening you could feel the pressure in the first 3 cylinders but absolutely nothing in the lower cylinder...... could this be a broken ring that was trapped and now free following the rocking of the flywheel. I appreciate this will require a strip down and I'm looking for any other possible suggestions and tips, etc, plus where to look for any difficult to get spare parts. I know little about the history of the motor other than it has been standing for a long time.

Thanks in advance,

Paul

 

[jerryjerry05]

Re: Help.... 1986 force 125hp

Lots of times the lower unit will stop it from rotating if the gears are gone.
The compression could be a bad piston/bad rings,bad head gasket.
You need to remove the head to see what damage is under there. Take it apart and post your results.J

 

[cairngorms]

Re: Help.... 1986 force 125hp

Thanks - I'll let you know how we got on.

 

[jason32038]

Re: Help.... 1986 force 125hp

Sounds like a piece of broken piston.