Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

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Seaman
Joined
Jul 16, 2007
Messages
63
Just bought it real cheap yesterday hoping it just needs carb cleaning/rebuild . Previous owner said it was running fine a month ago.
I cleaned the plugs
put fresh fuel 50/1
charged battery
shes running irratic up and down sounds like could be a miss.
don't remember if you are allowed to post a video. Hope I don't offend anyone by posting one
I didn't want to sink much money into this but if I can sort it out cheap I won't sell the motor for parts. I ordered carb kits from here today. Any suggestions would be helpful thanks
Here is a link to video one of the 3 should work. (I HOPE) :confused: hope it works

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<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid236.photobucket.com%2Falbums%2Fff220%2Fmarbles53%2FEvinrude%252090hp%252018%2520ft%2520Cobia%2FVID_20111019_152610.mp4">

http://s236.photobucket.com/albums/.../?action=view&current=VID_20111019_152610.mp4
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

have a look at the plugs after the muff run.....its missing quite bad. ( compression check first, then spark, then carbs)
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

The engine sounds like it is lean sneezing. If you've ordered carb kits, the carb overhaul should make a big difference in the way the engine runs. Make sure you clean all the carb passages with a good gas solvent like a Gumout type carb cleaner. Likely you have some dried fuel in some of the passages and the only way to get that out is with a good carb cleaner. Pull all of the jets out and visually inspect each one.
 

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Seaman
Joined
Jul 16, 2007
Messages
63
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

thanks for the info so far.
Today been working on it . It's not fireing 2 cylinders on left side from back of boat. I so far switched coils and no change substituted 2 wires also still not fireing on left side while running rough I removed wire from plugs on left side from rear of boat standing behind it and no diff. sounds like electrical to me . I jumped the power wires from the right coils to the left bank no diff. I dont have my compression tester I loaned it out. maybe a wire is messed with. I'm thinking if it's running on 2 cylinders and sort this out it may run smooth. Also engine started buzzing then now no power at key . Probably warning buzzer maybe it cuts power
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

Unless your engine is a TLCDF model, it should have a pair of identical power packs-one for each head. You can do a simple test be swapping these packs and see if the problem moves with the swap.
 

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Seaman
Joined
Jul 16, 2007
Messages
63
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

well Im positive no spark . left side need to look into the power packs. I will switch them . It's a model e90mlcdc .
 

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Seaman
Joined
Jul 16, 2007
Messages
63
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

I put the power pack from the good side to the non sparking side and viola! spark ordered a new one. see what happenes
 

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Seaman
Joined
Jul 16, 2007
Messages
63
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

Ok I used the Johnson decarb tuner and switched wires (small ones from power pack) still runs like crap. I did notice water pissing out was pretty cool to touch . rpms did come up and plenty of dark smoke. a couple of times it did run smooth for a second. I did take a video. please look at it. This time after a few minutes I did see smoke come from the round looks like a signal stat with red and yellow wires. I believe it's called the rectifier. got nervous and shut it down

http://s236.photobucket.com/albums/f...103_123739.mp4
 

guitman32

Petty Officer 2nd Class
Joined
Aug 14, 2010
Messages
114
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

Video not working. Did you already put in the new power pack?

Seriously you should drop all your tools and perform ignition troubleshooting procedures as outlined in the manual. Test stator, timer base, power packs, regulator, coils, etc for proper continuity, resistance and output.

This step will save you the most money rather than blindly diagnosing. And removing the carbs and inspecting cleaning rebuilding is mandatory if youre serious about keeping her running if you do sort out the miss.

Regulators aren't supposed to smoke fyi.

If you want to keep it cheap just sell it now.
 

guitman32

Petty Officer 2nd Class
Joined
Aug 14, 2010
Messages
114
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

I found the video...if that were my motor I wouldnt be revving it like that. Especially in the condition that its in.
 

N1NE1

Petty Officer 1st Class
Joined
Sep 21, 2008
Messages
238
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

mine sounded like this before and it happened after i accidentally turned the red knob on the primer solenoid , make sure its open
 

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Seaman
Joined
Jul 16, 2007
Messages
63
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

which way should that red knob be facing ? the one on top of the carbs right?
 

mekkamaz

Petty Officer 2nd Class
Joined
Dec 30, 2008
Messages
180
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

You may also consider checking the kill switch wiring as well..this is one of the most power pack killer issues if everything else is right(resistance, dva, etc)..it?s the black/yellow wire to the power packs..try disconnecting and re-test..
 

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Seaman
Joined
Jul 16, 2007
Messages
63
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

Made some Idle adjustments sounds a lot better and idle was too high still doesn't seem smooth to me going to test run soon. On the water and in the driveway are usually waaaay different. still can't find omc manual more specific so far stuck with the clymer 48-235 hp manual book sucks too much stuff you don't need to look at. Oh I ran another video after working on idle and changing fuel filter ren some seafoam too 1/2 to 3/4 bottle to 1 gal premix 50-1 Sunoco Ultra also already ordered volt rectifier so I put the new one and cleaned up the wireing too:redface:

http://s236.photobucket.com/albums/.../?action=view&current=VID_20111105_135215.mp4
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Just purchased 1986 Evunrude 90 Shes running really rough (SEE VIDEO LINK)

If you are looking for an original factory service manual, contact the original pulisher: outboardbooks.com or call Ken Cook co., in Milwaukee.
 
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