80's 9.9 Mercury

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Joined: 02 Aug 2016, 10:28

80's 9.9 Mercury

Post by caleywoods » 09 Aug 2016, 14:57

After a recent jon boat purchase I have reason to try and fix up an 80's model Mercury 9.9 2 stroke tiller outboard that was my dads. The motor has been laying on its side in a shed for the last 4 years and I don't know anything about outboards (yet).

What first steps should I take with this thing? I'm going to assume at a bare minimum that it will need the oil changed and new plugs before starting is even attempted. I picked up some water muffs so I can start working on it. I have some small engine experience from working on larger riding mowers - do these things have carbs that are prone to varnishing as well?

I've not picked it up yet so I'm not sure exactly what the model or year of manufacture is just yet but should know in the next day or two when I go pick it up.

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80's 9.9 Mercury

Post by driz » 08 Oct 2016, 14:30

Well 2 months later if you haven't already done it yea change out the lower unit oil. Be sure to fill it from the bottom till it runs out the top hole. Since you don't know how long ago the water pump impeller was changed get a new one. When they go you often don't notice until the damage is done so be proactive. The mix will be 50/1 oil . The big thing try not to use Ethanol gas in it if you can. It will run fine on the stuff just be sure to disconnect your hose at the tank end and let it run till it dies when you are done at days end if you do run ethanol gas. That will keep the alcohol from deteriorating the lines. If your original fuel lines are really stiff just replace them with new alcohol rated ones. They are all over Fleabay and cheap. I just got some myself.
Mercruiser parts are easily ordered by serial number. Find your SN and look it up on Mercparts.com and you can find the year of your motor. Iboats.com has access to the parts diagrams ect. Write the SN down as you will often refer to it.
If your engine runs you are lucky as most carbs will be stuffed up sitting around like that unused. Otherwise you will have to pull off the carbs and clean out the jets. Be careful as those carbs are expensive if you need a complete one. That can happen from letting them sit with ethanol in the bowls as it draws water right out of the air. Once you have it running and use it the thing should behave nicely for you (especially if you keep the ethanol out of it) [-X [-X
"I'm only here for the beer and yes fishing sure beats working" 1985 Tracker V17 Tournament 50 Merc =D>

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