1993 Johnson 150HP outboard

[bassFISHIN]

Went out fishing last Saturday and boat ran pretty well for most of the day. Fished about 4 hours with starting the boat at least 4 or 5 times with no problems. When we were set to go in the engine cranked a few times but would not turn over. It sounded like it was real close to turning over(plugs are all new). After 3 or 4 tries I thought I probobly flooded it so I let it sit for 15-20 minutes and tried again to no avail. Did this several times and just couldnt get it to turn over. We ended up trolling in for a good hour or so(while trying to start periodically along the way) and about 100 yards from the launch we tried again with reving the throttle a bunch of times and it finally turned over. Im not quite sure what the problem here is and why it is so inconsistent. Any help would be greatly appreciated. Thanks.

 

[scrampbell]

Re: 1993 Johnson 150HP outboard

I'd start by checking your spark on each cylinder at 1/2 inch gap. You should have a thick blue spark at that gap. I'm thinking it could be a weak spark giving you starting problems which could be caused by a number of things. Could obviously be the battery, but also could be caused by many of the components along the ignition system.

So, get a spark tester that you can set to a 1/2" gap and rule that out. Let us know how it goes.

 

[bassFISHIN]

Re: 1993 Johnson 150HP outboard

All I could find was an inline spark plug tester and each plug provided adequate spark according to the tester. For all 6 cylinders, the engine fired up perfectly first crank like there was no problem. Not quite sure where to go from there.

 

[clanton]

Re: 1993 Johnson 150HP outboard

You said engine would not turn over. Do you mean starter would not turn engine?

 

[mikesea]

Re: 1993 Johnson 150HP outboard

"reving the throttle a bunch of times and it finally turned over"
That does nothing,you dont have an accelarator pump in Outboard carbs,your priming is done thru the keyswitch.Are you sure your primer is working?do you hear an audiable click when pushing the key in,if so,are you squeezing the ball till it gets hard,that pressurizes the primer system.remove your cowl9ing and insure your primer is actually workingthen look for any leaks,you may have a hose off

 

[jonesg]

Re: 1993 Johnson 150HP outboard

Opening the throttle helps when the engine is flooded, the butterfly's open for more air intake. I flooded mine by mistake ( leaned on the ignition key) and cranking the engine WOT got it spluttering anjd it started soon after.

Question is, how did you manage to flood it?

 

[Chris1956]

Re: 1993 Johnson 150HP outboard

Jones has given good advice for all kinds of motors. If you think she is flooded, push the throttle wide open and leave it there while cranking. She will normally unflood, and if nothing else is wrong, will start. As soon as she fires, cut the throttle back to control the revs.