1986 150 Johnson no Power

haybarn

Seaman Apprentice
Joined
Sep 27, 2005
Messages
38
Saturday the boat was on the river and running WOT between 4500 and 5000 rpm. I stoped it for a minute to turn around and started to head back. I gave it full throttle and the boat would not plane out or anything. At this point WOT throttle was between 2500 and 3000. I shut it down looked at the motor nothing looked out of the ordinary. Everthing was plugged up, no loose wires. I tried it again and no change. I stopped the boat left it running at idle and checked for spark. It appeared all six had fire. The boat when shut off starts right up no problem and sounds great at idle.<br /> Sunday I went and did a compression check all 6 cylnders read at 90 psi. Motor is defanitly getting gas to all six cylinders. <br /> Some of the plugs looked a little wet from gas and oil mixture. Attempted to start, started just fine. <br /> I am hoping someone here can help me get this trouble shot and help me figure it out. HELP!!!
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: 1986 150 Johnson no Power

Sounds like your losing ignition to one or more cylinders haybarn. Do a spark test on each cylinder across a 1/2" gap and see what ya' get. More often than not, when an engine loses power that quick, it's ignition related.<br /><br />And, get those rpm up at WOT. You should be turning 5500 plus.
 

haybarn

Seaman Apprentice
Joined
Sep 27, 2005
Messages
38
Re: 1986 150 Johnson no Power

The spark test you called for it wont do a 1/2 inch at all maybe a 1/4 inch. I am thinking also this problem could have been a long time coming, now that you have mentioned the 5500 RPMs.<br /> Do ya thing it might be a stator or regulator
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1986 150 Johnson no Power

The regulator has nothing to do with the spark. Suggest you start your ignition check process with the cheapest item, going to most expensive. Start with the coils/wires, then power packs, before you go to the stator.
 

haybarn

Seaman Apprentice
Joined
Sep 27, 2005
Messages
38
Re: 1986 150 Johnson no Power

Ok, I went out this morning and took my meter out. I did an OHMS cheack on both power packs. What I found is that one back was reading higher and constantley. The other pack was reading low and inconstantley. Do ya think this a good way to check. What do you think?
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1986 150 Johnson no Power

A factory service manual is very helpful. There are two tests indicated for packs: 1. The ohms test is the way to determine if the diode is functioning propely. A normal diode will read resistance in one direction and an infinite reading in the other. 2. There is also a neon test light procedure to check the actual functioning of the packs. Packs need to pass both tests.
 

haybarn

Seaman Apprentice
Joined
Sep 27, 2005
Messages
38
Re: 1986 150 Johnson no Power

Hey thanks for the help that you all have given me. I went on ahead and replaced the pack yesterday and man the old motor came to life. As far as teh 5500 RPMs I was between 5000 and 5500. The motor is up to where it is supposed to be. I am going to play with the props. Thanks foir the help. <br /> I have learned one thing and that is just because the wires are throwing spark it always working right.
 

haybarn

Seaman Apprentice
Joined
Sep 27, 2005
Messages
38
Re: 1986 150 Johnson no Power

(correction) It is not always working right
 
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