'94 Merc 150hp Outboard Electrical Help

ClassyGlassy

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Dad has the above mentioned and he ran it while the overheat alarm was going off for 30 minutes until it overheated the wires going across the motor one day and it started smoking so he shut it down. A friend of his :mad: started cutting and splicing the burned/melted melted wires, replaced the thermostats, and replaced the impeller for him a few days later and then they test ran it in a barrel of water for a couple of minutes with no problems. So dad decides to travel half way across the state and run in Gunnison Reservoir where it started smoking after 10 minutes of running across the lake. Sooooo.......he shut it down and hasn't run it in 2 years now!

So dad decides to have me look at it finally and during my inspection I find it looks like the VRO control/alarm wires are what started to melt and another control box of some type that bolts across the top of the powerhead.

Here's my issue:

I want splice all new wires to the VRO controller for him to run it until the tank is close to empty then get rid of the VRO system all together and have him premix. He agrees to premix and understands why......

Second, I need to find out what this second control box is that was mounted on the top of the powerhead. It has 1 ground wire, 1 Red with White wire, and 1 White with Black wire. The ground is ground to the powerhead, the Red/White and White/Black go to connectors by the control switch. This box in particular shows some overheating damage as the bottom of the box, closest to the powerhead, is cracked and bubbled and is no longer connected to the plastic cover! Can someone tell me what this box is?
 

Faztbullet

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Re: '94 Merc 150hp Outboard Electrical Help

Idle stablizer/spark advace module.. chunk it and set timing at 20 degrees
 

ClassyGlassy

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Re: '94 Merc 150hp Outboard Electrical Help

Do you have a diagram/picture of where I adjust the timing? Do I use a regular automotive timing light? Which plug wire do I clip my timing light to?
 

Chris1956

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Re: '94 Merc 150hp Outboard Electrical Help

Use a regular automotive timing light. The timing pointer is on the ugly plastic flywheel cover. Find #1 spark plug and clip the timing light to it. Number 1 is the highest of the two top plugs.


You might invest in a service manual. I have a Clymer for that exact motor, and it is reasonable good for simple stuff like tuneups. Use a Merc Manual for the more involved stuff like overhaul.
 

ClassyGlassy

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Re: '94 Merc 150hp Outboard Electrical Help

Thanks Chris, I found the pointer and where I can read the timing, where do I adjust the timing? There isn't a distributor so I'm assuming it's an adjustment screw on the throttle linkage like on my older Merc 1500? The adjustment screws aren't marked like mine are though......:confused:

I would buy a Clymer or Seloc manual but it's my dad's boat and he won't get one.......I'm thinking of just getting one and calling it a Father's Day gift. But that will take me 5 days or so before I get it and I need to get it timed now......therein lies my issue. I will still get him the manual but in the meantime I need the info so I can get it running.

Thanks.....
 

Jacket4life

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Re: '94 Merc 150hp Outboard Electrical Help

Your Dad sounds like my Dad. He let his sit 2 years b/c he wouldn't give the $30 for a manual so I could fix it! I refused to do it w/out the manual, and he wouldn't do it by himself without my help, so we had us a good old Mexican standoff until he caved this spring and bought the manual!
 

ClassyGlassy

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Re: '94 Merc 150hp Outboard Electrical Help

That's basicly why I have it in my driveway right now........I told him to get it here and I would fix it. He felt guilty so he's been cutting wood and clearing trees in my yard all day as payment.

I succesfully put in the new engine harness, rewired the VRO Control harness and put new shrink tube on it plus rerouted it up off of the powerhead, put new thermostats in it again, new fuel line, new primer bulb, new pitot, and got rid of the idle/advance controller.

I'm getting some fuel tomorrow so I can run it and time it if I can find where I'm supposed to adjust the timing at.
 

Jacket4life

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Re: '94 Merc 150hp Outboard Electrical Help

Yeah, I've been working on ours since March. I have a thread on here about forward/reverse backwards if you want the WHOLE story! LOL. My manual stops at '89, or I'd be glad to help...Someone on here will hook you up, I'm sure.
 

Jacket4life

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Re: '94 Merc 150hp Outboard Electrical Help

Oh, and you sound a lot handier around them than me, I'm sure it will work out for you...
 

Jacket4life

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Re: '94 Merc 150hp Outboard Electrical Help

OH, and you haven't said how you will run it, if you run on muffs you can't run it WOT, but you prolly already know that.
 

ClassyGlassy

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Re: '94 Merc 150hp Outboard Electrical Help

I have a horse tank I back it down to......
 

ClassyGlassy

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Re: '94 Merc 150hp Outboard Electrical Help

Run the engine, disconnect the fuel line at the motor until it dies.
Remove the throttle cable.
Remove all spark plugs except for #1.
Hold the spark advance lever against the stop and crank the motor with the timing light.
Adjust the advance screw to 20 degrees.
Lock down the advance screw nut.
Reinstall all spark plugs/wires.
Reinstall throttle cable.
Reinstall Fuel line.

Does this sound right?
 

ClassyGlassy

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Re: '94 Merc 150hp Outboard Electrical Help

I just read that I need to set it at 22 degrees at cranking speed to obtain 20 degrees at WOT
 
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