25 hp merc ob won't start

tsteven2

Recruit
Joined
Apr 13, 2003
Messages
2
I have 1994 Mercury 25 hp outboard. The boat has sat for 18 months. Before, it ran like a champ. Now it won't start. I have replaced the gas and sparkplugs. Any suggestions? I would really like to get it running today.
 

jim dozier

Lieutenant Commander
Joined
Jan 8, 2003
Messages
1,970
Re: 25 hp merc ob won't start

Squirt some premix oil/gas in the carb throats. You may have to remove the airbox on the carb fronts. If you're lucky it may run from there. If it fires but doesn't run well, after sitting that long you may need to clean and rebuild the carbs. Keep an eye on the water pump also, they deteriorate with age.
 

Fouled Plug

Ensign
Joined
Jun 29, 2001
Messages
935
Re: 25 hp merc ob won't start

Check to make sure you have spark first, then check out the carbs. I've had some luck with motors that have sat a while by dropping the carb bowls and spraying Chemtool or carburetor cleaner everywhere I can reach. That old gas can really gunk things up. Jimd has good advice about the impeller. Even if the motor appears to pump water at first, it's likely the water pump will need attention before you run it much.
 

tsteven2

Recruit
Joined
Apr 13, 2003
Messages
2
Re: 25 hp merc ob won't start

jimd and fouled plug, thanks for your advice. With a little squirt of gas/oil mix in the carb it fired right up! I will still take it apart and make sure it is cleaned.<br /><br />You are both gentlemen and scholars!
 
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