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73 mercury 1500 inline 6

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bbennet2

New member
Alright guys Im new here so forgive me if I screw this up. I bought a mid or early 70s model venture 1800 bass boat with a 73 mercury 1500 on the back. i knew it didnt run when i bought it. i gave 250 for the entire boat trailer motor. i dont know much about outboards. so i started at the mercontrols and went thru the external harness which is good, replaced the internal harness which was chewed up. motor is not locked up. but is real slow turning. On a full battery it sounds like it is almost dead. took all plugs out and spins great. my question is 1. would it be a safe bet to go ahead and replace the switch box? 2. The motor didnt have the stator on it when i bought it, but i have been told on this engine the stator was only used to recharge the battery if so where does it get spark? and 3. the plugs that were in were flat plugs or gapless i guess woukd be correct, but i have been told that theplugs should be gapped plugs. any help fellas would be great. 1st boat and want to learn please help.
 
Before you spend money,compression test,110psi+.Spark test,looking for 3/8",if you have good spark,switchbox is likely good. Pull the distributor cap,have look at the wee carbon brush,make sure it's ok.
It's a two wire stator,only charges/tops up the battery.
Clean and tighten all wire connections,especially the ground at the battery is tight.
Slow turnover could be a lazy starter.If you can do it yourself,check the brushes,give it a good cleaning or take it to any auto electrical shop.
http://www.marineengine.com/parts/mercury-outboard-parts/1500/3502806-thru-4865677-usa This is a link to diagrams of your outboard.Welcome to a highly contagious disease............,old mercs,:D Good luck
Forgot to say,give the carbs a good cleaning,if they are old and hasn't been run in some awhile,a rebuild would be the right way to go and a new impeller and change lower unit oil.
Mix at 50:1 fuel and don't run it without water hook up or in tank.
 
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i appreciate the posts. so today i went and picked up a compression tester and checked all cylinders 12356 all produced approx 60 psi super low, 4 produced 35 psi. i removed the side cover on the top two cylinders and the rings are defined and are sitting pretty high. why would everything be 60? i read the instructions and it seems simple stupid. i am also having to jump off the starter, no key.
 
Been pragmatic,break her and sell any good parts to offset the cost of a replacement.
Stuck/broken rings,scored cyls will result in low compression.A difference of 10% down the line and I would have suggested borrowing another compression tester,but with a difference of almost 50% on number four cyl,you'll need to split her to see the damage.I haventaclue how much it would cost to rebuild,assuming that you are in the USA,rough guess,$2000+. I'm sure someone will jump in to correct me if I'm wrong.Might be cheaper/handier to buy a refurbished powerhead.
Me personally,I would split her just to see for myself:D
 
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