Motor won't turn past compression stroke

[bullit1119]

I have a 1977 mercury 1500 that has started giving me problems. I can turn the flywheel by hand with relative ease but hook it to a battery and it wont spin past compression. Can any one help on this?

 

[alldodge]

Re: Motor won't turn past compression stroke

I have a 1977 mercury 1500 that has started giving me problems. I can turn the flywheel by hand with relative ease but hook it to a battery and it wont spin past compression. Can any one help on this?

Sounds to me it's either the battery is weak, bad connection to the battery and starter, bad ground, or starter needs replacing. Put a volt meter on the starter and try cranking the engine, battery should not drop below 10 volts, should be higher.

 

[bullit1119]

Re: Motor won't turn past compression stroke

Thanks for reply, ill give those a look and go from there. Do i need a Marine battery or will regular car battery work?

 

[GA_Boater]

Re: Motor won't turn past compression stroke

Just about any well charged battery should work for testing. For on the water use, you should use a marine battery because they are built stronger internally for all the bangs and bumps a boat sees as it it hits wave, wakes, etc.

 

[bullit1119]

Re: Motor won't turn past compression stroke

Just about any well charged battery should would for testing. For on the water use, you should use a marine battery because they are built stronger internally for all the bangs and bumps a boat sees as it it hits wave, wakes, etc.

Thanks GA