Motor Frozen 80 HP Mercury Outboard

[blhdiscgolf]

I hope someone is out there this afternoon, Im trying to help a young man who may have seized the pistons on his Dad's 80hp mercury outboard. Is there any way I can test this. If you click the motor on the start pops up and locks immediately into the flywheel at the top. I tried putting it in nuetral and manually trying to turn the flywheel, it on moves an inch maybe in each direction and wont move.<br /><br />Any suggestions

 

[Laddies]

Re: Motor Frozen 80 HP Mercury Outboard

Don't sound good pull the port covers and ck. the pistins and cyl.

 

[blhdiscgolf]

Re: Motor Frozen 80 HP Mercury Outboard

Shouldnt I be able to turn the flywheel at the top if the engine is in nuetral

 

[blhdiscgolf]

Re: Motor Frozen 80 HP Mercury Outboard

Originally posted by Laddies:<br /> Don't sound good pull the port covers and ck. the pistins and cyl.

 

[blhdiscgolf]

Re: Motor Frozen 80 HP Mercury Outboard

Laddies, shouldnt I at least be able to manually turn the flywheel at the top if the engine is in nuetral??????

 

[MortenH]

Re: Motor Frozen 80 HP Mercury Outboard

The flyweel should turn freely when in neutral, if your spark plugs are removed. This doesn't sound good. You may have to tear her down..<br /><br />-M-

 

[Silvertip]

Re: Motor Frozen 80 HP Mercury Outboard

You need to determine if the engine is seized or the lower unit is locked up. If either is seized, you may not be able to turn the engine over even if it is in neutral. Remove the lower unit and then turn the engine manually. If you can't, it's seized. If you can, the lower unit is locked up.

 

[briannh1234]

Re: Motor Frozen 80 HP Mercury Outboard

If the motor appears to be seized after removing the lower unit, you may be able to free it by pulling the plugs and dumping liberal amounts of marvel mystery oil into the plug holes. It would be good to have the engine mounted so the pistons are vertial.<br /><br />If it's seized due to lack of use - this should work. If it's seized due to piston failure - then teardown is the only option.