NOOB BOATER HERE...1981 Johnson 90hp running weird...

Pain'n'da'boat

Seaman Apprentice
Joined
Jun 10, 2009
Messages
42
Let me begin by saying that I have been trying to search these threads to see if the answer to my question exists, and no luck thus far.

My boat at WOT was having a problem-it would choke out and go from 4-5k rpm to 2100 rpm and when you let off the throttle a little bit, it dies.

It was doing this when I first got her wet, (after 4 yrs of sitting and 3 mnths of reviving her) then ran it out a few times and the problem dissapeared...or so I thought.

I ran it last weekend for 10-15 min solid @ WOT w/ no problems just like the last 3 times out, fished, and on the way back it started bogging down again and won't idle...

-the fuel bulb has full pressure when the bogging is happening. I do a 50:1 mix of midgrade 89 oct with Quicksilver-

Will changing the spark plugs more or less solve this issue if they have not yet been changed, and if so, any recommendations as to what kind of plug to use...it has some NGK-R plugs in at the moment that don't look that bad.

Edits: Should I add a fuel stabalizer to it? Will that help?

Any help would be greatly appreciated!! I am going to change the plugs anyway this weekend but don't want to get stuck on the lake at 4 am this weekend and want to know if it sounds like there may be a different problem.

BTW- I love this forum and the mods here rock!
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Champion plugs are best.

Have you tried pumping the fuel bulb when it starts to bog down?
Do you have a water seperator installed yet?
Is the tank vent open and clear?
Drain fuel from the carb bowls and let it settle in a bottle, look for water.

Get the factory manual, its a nice motor.
www.outboardbooks.com
 

Knightgang

Lieutenant
Joined
Oct 6, 2003
Messages
1,428
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Champion plugs are best.

Have you tried pumping the fuel bulb when it starts to bog down?
Do you have a water seperator installed yet?
Is the tank vent open and clear?
Drain fuel from the carb bowls and let it settle in a bottle, look for water.

Get the factory manual, its a nice motor.
www.outboardbooks.com

All of these suggestions are a great place to start. I will say that it sounds like a full restriction issue. Once the engine fires and fuel is flowing, the bulb should no longer be firm. When you check the bulb after the engine dies and it is firm, then it sounds like the fuel flow stopped somewhere after the bulb. Check all of your lines, and your fuel pump. Might even have needles sticking in the carbs and they may need to be disassembled and cleaned, possible rebuilt.

Give these suggestions a go and let us know what you find...
 

Pain'n'da'boat

Seaman Apprentice
Joined
Jun 10, 2009
Messages
42
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Knightgang you were dead-on. The needle on the top carb was stuck and not allowing fuel to half the motor. Bought a rebuild kit from iBoats, took about an hour to rebuild them (first timer too, found a video post on youtube that showed me exactly how to do it (manual didn't hurt either)

I know this is an old issue, I just wanted to let you know that your troubleshooting was right on. Thanks again for the advise and just know that this is the ultimate in boating forums.
 

royal0014

Master Chief Petty Officer
Joined
May 6, 2010
Messages
874
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Hey 'Pain' , you were a pain to me :p

Sitting here reading your post, when my 9 y/o walks up behind me, sees the 'Warning' at the bottom of your signature............. I get a question I should not have to answer yet!!!!!

Thank You
 

mamm7215

Petty Officer 2nd Class
Joined
Apr 28, 2010
Messages
184
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Horny=wanting to go fishing...
 

Pain'n'da'boat

Seaman Apprentice
Joined
Jun 10, 2009
Messages
42
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Horny=wanting to go fishing...

I have only been a parent for 6 years but I can tell you that the above quoted response would have taken me literally 5 seconds to figure out and tell my kiddo...

Sorry that my innocent adult humor caused you a hardship with your 9 y/o. I will change from hard-to-read bright yellow ink to a darker more easily read ink so that you are easily aware that there is something written worth hiding from your child.

How your 9 y/o saw it at a glance from behind you is beyond me since I already know what it says, and it's still hard even for me to read.

BTW, this sticker is on my boat and I have only gotten positive responses from it, mostly a big smile and and/or thumbs up.

I thought it was against Amish teachings to use the internet....

*quits internet*
 

Pain'n'da'boat

Seaman Apprentice
Joined
Jun 10, 2009
Messages
42
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

Nice, I guess somebody deleted my signature. No first amendments allowable in here I guess.
 

royal0014

Master Chief Petty Officer
Joined
May 6, 2010
Messages
874
Re: NOOB BOATER HERE...1981 Johnson 90hp running weird...

:confused: Won't apologize that you took my response that way. Did think it was funny, 'cause I aint Amish :D

I see you or someone changed your signature. Not as funny that way. Change it back for all I care........
 
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