Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

MattinTally

Seaman
Joined
Dec 6, 2009
Messages
58
I'm looking for the correct cold start procedure for my 1988 90Hp 3-Cyl Mercury outboard serial #B250374.

I'm having one hell of a time getting it to start when motor and outside air is cold (bout 45 degrees).

This is what I THINK is the correct procedure:

1. Trim motor completely down, cavitation plate even with bottom of boat
2. Open valve on gas tank
3. Turn key one position
4. Raise throttle level HALF WAY
5. Squeeze Primer bulb until firm
6. Push key in & hold for a count of 5 to 8 seconds (fuel is gravity fed into carbs)
7. Keep key pushed in & turn all the way to ignite
8. If it tries to fire, but doesn't start, turn the key again WITHOUT pushing key in again

If the experts have anything to add to this, or corrections, the information would be greatly appreciated.

Thanks in advance,

Matt, Tallahassee, FLA
 

Dave1027

Lieutenant Junior Grade
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May 25, 2010
Messages
1,081
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Try it this way. It works flawlessly for me.

1. Open valve on gas tank
2. Pump up primer bulb till full and hard
3. Set neutral only throttle to 10%
4. Turn key to on
5. In one motion, push in key and turn to start. Hold it in that position till it fires. Takes my motor less than one second.
 

MattinTally

Seaman
Joined
Dec 6, 2009
Messages
58
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Nope, doesn't work like that when cold outside and motor is also cold. That's the way I've been trying.... other posts on this forum seem to indicate that its necessary to push & hold key in before turning to full ignition..... and motor must be trimmed low in water since fuel gravity-feeds into carbs vs. electronic pump.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Nope, doesn't work like that when cold outside and motor is also cold. That's the way I've been trying.... other posts on this forum seem to indicate that its necessary to push & hold key in before turning to full ignition..... and motor must be trimmed low in water since fuel gravity-feeds into carbs vs. electronic pump.

Could you be trimming it in too far. It needs to be about level, but it's also counterproductive to bury the exhaust too deep in the lake. With my bass boat with all the weight in the back, that's trimmed up about 1/3.
 

Dave1027

Lieutenant Junior Grade
Joined
May 25, 2010
Messages
1,081
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Nope, doesn't work like that when cold outside and motor is also cold. That's the way I've been trying.... other posts on this forum seem to indicate that its necessary to push & hold key in before turning to full ignition..... and motor must be trimmed low in water since fuel gravity-feeds into carbs vs. electronic pump.


You only have to trim far enough down to make the mercury switch. I have accidentally started mine in the up position before. It was kind of at an angle.

Your method is not the same as mine. I have almost the same motor. If yours does not start going by my method then you have a malfunction.
 

trendsetter240

Lieutenant
Joined
Jun 22, 2009
Messages
1,458
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Nope, doesn't work like that when cold outside and motor is also cold. That's the way I've been trying.... other posts on this forum seem to indicate that its necessary to push & hold key in before turning to full ignition..... and motor must be trimmed low in water since fuel gravity-feeds into carbs vs. electronic pump.

That motor has a fuel primer. When you pump the gas line ball fuel is pumped into the carb bowls. Fuel is also fed down from the #1 carb to the primer.

When you push the key in the primer valve opens and fuel is fed directly into the intake manifold bypassing the carbs.

Do you hear an audible click coming from the powerhead when you push the key in? If you do not then the primer solenoid is not activating and no fuel is being let in. Test for 12v in the black/yellow wire at the primer valve. If there is no power then test for power coming from your ignition switch.

If you've got power at both of the above then the solenoid is bad and needs to be replaced.

If you do hear the click then next thing to check is the fuel lines surrounding the primer for any blockages.

The motor should start without having to crank it over excessively and without the throttle open half way.
 

MattinTally

Seaman
Joined
Dec 6, 2009
Messages
58
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Yes, hear the click when key is turned. Solenoid is working. Already checked fuel filters and the surrounding lines. Had friend take off line from enricher while I turned key & he got soaked w/ gas. Bulb stays firm. Motor is not excessively deep in water. It wasn't this hard to start when outside air was warmer -- in the 70s. Starting @ 45 degrees after sitting outside in mid 30s weather all night seems to be a factor. Fuel is brand new. Tank is not old. Primer bulb & line are new.... Checked and have great spark, clean plugs.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

How does it act when its cold?? Does it hit and die? Try the steps below as this is how to do a old tired inline...

1. Trim motor down level or slightly tucked under
2. Open your valve on gas tank
3. Turn key one position
4. Raise throttle level HALF WAY
5. Squeeze Primer bulb until firm
6. Pull "kill cord" and push key in & hold for a count of 5 to 8 seconds while cranking
7. Reinstall cord and turn all the way to ignite
 

donaldboyer

Cadet
Joined
Oct 15, 2010
Messages
26
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Gidday Mate,

I have an owners manual for this engine as I have one myself. I can scan the appropriate pages for you if you like. Just let me know.
Donald.
 

Yovi Bay

Cadet
Joined
Nov 10, 2010
Messages
21
Re: Anyone have link to Owner's Manual for an '88 90hp 3-Cyl?

Hi Donaldboyer

i have a Merc 50hp '88 and i'm pretty sure that manual is for 1965-89 40-115hp outboards???

is that the one you have???

if so id be ever so greatful for a scanned copy

see my post called new to boating
http://forums.iboats.com/showthread.php?t=449149
to understand


any help greatly appreciated.
 
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