'91 90hp mariner

[crash666]

Hi, I just bought a boat last weekend and I'm having a few probs with the outboard. I have real problems starting the engine when cold. It runs nicely when it finally starts, no hesitation even though it doesn't sound like an engine that's wide open I can live with the performance there but i can't start it. I don't know much about "outboards" but i am handy and decent with this kind of stuff. I noticed the plugs are brutally fouled when i pull them out "soaked". I tried following the manual today to lean out the mixture but it wasn't really going the way the book said, it's a little better for starting but my plugs are still soaked. Any Ideas ?
couple of other things i noticed,
The tach only registers with the starter running
is it normal to see turbulence before the fuel filter from time to time ?


any help would be appreciated.
Thanks, Steph.

 

[crash666]

Re: '91 90hp mariner

I'd appreciate it if someone could point me in the right direction 'cause i'm out of ideas.
I broke the bank and i'd like to fix it myself if i can but i'm out of ideas.
no matter what i do the plugs come out soaked. As far as i can tell there is plenty of spark but it just won't start.
the times i got it running it ran well but it took one and a half battery to start it.

HELP
ANY ONE ???

 

[saumon]

Re: '91 90hp mariner

Thoses mid-range triples are usually easy starters. Squeeze primer bulb till firm, turn key one notch, lift throttle lever half-way, hold enrichener (push key) for a few sec. and start within a few sec. of spinning the starter.

IF you're following this exact procedure and are still having problems, it could be a lot of thing. It could have lost a cylinder, having a bad coil or simply a dirty carb. The more efficient approach with an engine of unknown history was to check, IN THAT ORDER, for:

1- good, even compression on all cylinders (over 100 psi and within 10%)
2- strong (blue, crisp) spark at all cylinders (jump at least a 7/16 gap)
3- fuel system checkup (from the tank pickup up to the carbs with everything between, including the fuel lines, the primer bulb and the fuel pump)

So, if compression and spark test ok, i'd clean and rebuild the carbs and fuel pump...an easy job to do. You'll waste your time trying to adjust a dirty carb!

Here's the OEM Shop manual for your particular engine (the password for extracting each file is "ribforum"). All the procedures were clearly explained:
http://rapidshare.com/files/213240342/70-75-80-90-100-115.rar

 

[crash666]

Re: '91 90hp mariner

Thanks for the reply,
I don't have an enrichener button just a fast idle lever
The messed up part is that the engine runs well at speed even low speed.
It just won't start when cold. when it's warmed up turns over once and starts but when it's cold it kills a battery right dead trying to start it. I've been messing with the low speed mix screw but i guess the only thing left is to rip apart the carbs.

 

[saumon]

Re: '91 90hp mariner

I don't have an enrichener button just a fast idle lever.

I'm sure there's one: you simply have to push the key in. It's a very simple system: it take fuel/oil mix from the top carb bowl and dump it right into the crankcase (it's gravity fed). BTW, it really help for cold starting

 

[crash666]

Re: '91 90hp mariner

So by pushing the key in I'm actually priming the engine ?

 

[crash666]

Re: '91 90hp mariner

Is this a one shot deal or does it keep putting xtra gas in ?
Is there a way i can test the enrichener to see if it's flooding my engine when i try to start it ? The plugs are always soaked when i take 'em out.

 

[saumon]

Re: '91 90hp mariner

So by pushing the key in I'm actually priming the engine ?

Yes, as the switch is activated, it let flow fuel/oil mix from the carb right into the block. As it only work by gravity (it's not an electric pump), you have to hold it for 5-10 sec. if you want some fuel in.

It's a 2 in. cylinder with 2 hoses, connected to the top carb bowl and to the crankcase. Disconnect the one that goes to the crankcase and activate the switch manually by pressing the button underneath, you should see some fuel flowing.

Anyway, try starting your engine with the procedure i gave you and report back...

 

[crash666]

Re: '91 90hp mariner

Thanks dud, that did it.
It wasn't working, replaced it and it fired right up.

Any insight on my tach ?
It only moves when the engine is turning over with the starter.
As far as I can tell on the net the gray wire is right and I tried to replace the other two with a direct ground and power but nothing.

Any ideas ?