1985 Mercury V6-150 hp outboard-no power

[carsi54]

I just bought a used boat and motor. Motor is a 1985 V6 Mercury 150hp BlackMax. It's been sitting for 2 years. It seems to run ok using muffs but boggs down on the water at full forward. Only attains trolling speed. I first filled the fuel tank with fresh fuel and oil mix. Any suggestions..I'm new to the forum..thanks

 

[clanton]

Re: 1985 Mercury V6-150 hp outboard-no power

Remove carbs and clean(do not mix carb jets different sizes in the carbs), replace waterpump,replace fuel pump diaphram, check water poppet valve, check tilt/trim fluid, check spark should jump 7/16 gap, change gear oil. Check compression first. 100 lbs + each cylinder. Start run engine check operating temps.

 

[carsi54]

Re: 1985 Mercury V6-150 hp outboard-no power

Thanks clanton for the reply. I guess there's no getting around rebuilding the carbs. I was told the kits are $60. each carb but looks like it's inevitable. I was hoping for a simpler solution. I'll check the compression and let you know the results. I've seen where some people used carb spray. Would it be worth trying first?

 

[clanton]

Re: 1985 Mercury V6-150 hp outboard-no power

You can just buy a gasket kit, for about 7.00. I did a 1986 v6 that sat for 6 years. You should take the carb apart to clean the jets and passages, check float needles, and set the floats Most of the time if you remove the main jet plug and spray the carb in the float bowl, it just breaks the junk loose and it falls to the bottom of the carb.

 

[BKool68]

Re: 1985 Mercury V6-150 hp outboard-no power

Let me add that you should check and replace all fuel and oil lines. Also make sure to use plastic straps and not hose clamps that can cut into the lines and cause an air leak. Don't forget to check the lines at your remote tank too, asuming your oil injection is still hooked up.

 

[carsi54]

Re: 1985 Mercury V6-150 hp outboard-no power

Today I started out by replacing the primer bulb and engine fuel line connector (just in case). Tomorrow I'll check the compression. Then I'm going to bring it to a lake to try it again. Maybe I'll get lucky and see if by depressing the choke or squeezing the bulb while moving it changes anything. Then I'll go from there. More than likely I'll have to do as you said and take apart the carbs and clean them. I'll let you know. Thanks again.

 

[carsi54]

Re: 1985 Mercury V6-150 hp outboard-no power

Thanks BK for the reply. I did change the line from my tank (40 gallon, permanent), and connectors and bulb. I don't have any oil injection. I have enough trouble as it is.LOL

 

[carsi54]

Re: 1985 Mercury V6-150 hp outboard-no power

Well I took apart and cleaned and replaced gaskets in the 3 carbs. The fuel pump, enrichener valve/choke, all test good. Took it for a test ride. Still have the same problem. While trying to check the timing I discovered that I do not have a spark to number 1 cylinder. I've checked my service manual and it points to possibilities of a bad coil, bad switchbox, bad stator, or bad stabilizer module. Is there a common problem with one of these in this particular motor?

 

[clanton]

Re: 1985 Mercury V6-150 hp outboard-no power

I think so, all 5 items you listed. Move the bad cylinder coil wire to different coil, if other coil does not fire, pack may be bad. Check all grounds.

 

[carsi54]

Re: 1985 Mercury V6-150 hp outboard-no power

Now why didn't I think of that.. LOL..........thanks