1984 Johnson 15 hp issues

[goblerblaster]

I have an 1984 Johnson 15 hp -model #J15RCRM-. When I bought it a few months ago, it was hard to start the first time, but then was fairly easy to start- 5 or 6 pulls- after that over the course of several weeks. I ran it in a barrel with a heavy dose of Seafoam. It would idle as long as I wanted it to- like over an hour at a time. Finally took it to the lake and it started as usual but would not plane the boat when I opened the throttle, bogging down and dying. Brought it home and put a carb kit on it. Carb was really dirty and the float gasket had crumbled up inside the float bowl. I put it back together , pumped the bulb, and it started on 2nd pull. Took it to the lake and it started on first pull and it ran WOT perfect, and it idled perfect. I disconnected the gas line and let it idle until it seemed to run out of .gas.

I brought it home and a week later took it back to the lake. Motor sputtered on first rope pull then started and idled perfect on the second pull. I was letting it idle and heard the idle speed up like it was running out of gas. In a few seconds it died and would not even hit much less restart. It had maybe idled for 20 seconds total. I had noticed that when I went to pump the gas bulb- after hooking up the fuel connector to the motor - I noticed that the bulb was already hard and it didn't feel like any gas was being pumped into the motor. This was before I started it, but I didn't think much about that until it died and would not re-start. I assumed that the float must be stuck and not letting any gas in. I figured there must have been some gas left in the carb from when I ran it a week ago and that was what had just run out. Brought it home...

I removed the fuel line from the carb and pumped the bulb. Gas was coming out of the fuel line. I pulled the starter rope and gas would squirt out of the fuel line, so I assume the fuel pump is working. When I would pump the bulb hard- I mean really squeeze it hard- I got to seeing gas coming out of the front of the carb, so I figured the needle valve was not blocking the gas from getting to the carb when the float bowl was full of gas. I took the carb apart and blew air through it, checked for clogged jets, etc. and could find no problem. So, I reinstalled the carb, pumped the bulb- this time it felt normal when pumping like gas was going into the carb- and it still will not even hit. This time I could not pump the bulb hard enough to make gas come out of the front of the carb. I checked the plugs and they are getting good spark. I thought maybe it was flooded , so I waited 2 hours and tried again. Still not hitting. Pulled the spark plugs and squirted gas into the plug holes. Still won't hit. I waited 2 more hours and tried again- same result.

Any ideas???

 

[racerone]

Check for spark.

 

[oldboat1]

Do you have that "heavy dose of Seafoam" in the gas tank?

 

[goblerblaster]

Yes, it was sparking great... Heavy dose of Seafoam was replaced with fresh gas before the trip where it was running perfect. UPDATE:: Went out this afternoon after not trying to start it for about 4 hours in 85 degree heat, pulled the rope and it hit and sputtered. I had removed the gas line from the motor. Pulled it 8 or 10 times with it hitting and sputtering every pull. Finally, it started and I plugged back up the gas line. Ran and idled perfect for 15 minutes until I killed it. Waited about an hour and tried again and it started and ran perfect- on the first pull. Waited about 30 minutes and started first pull and ran great. All this starting and running is on muffs by the way. I 'm leaving the gas line hooked up to motor and will take to the lake tomorrow and give an update.

Any ideas of what might have happened other than maybe being flooded?

 

[oldboat1]

The air/fuel mix on my 9.9s is a little less that one turn open. For cold starting, though, I often have to richen it about a quarter of a turn until it warms up a bit, then return to the leaner setting. The service manual should tell you the initial setting is 1 1/2 turns open (then adjust to fine best setting).

need to measure spark with a spark tester (open air). There is also the issue of compression. Best to check it.

Having said that, I've had problems similar to what you describe and ended up using a Phillips screwdriver and relieving pressure (and gas!) in the line between the hand primer and the motor. After that, I was able to fill the carb normally. I think the problem was probably a bad check valve in the bulb or the spring in the connector(?)

 

[goblerblaster]

Sorry for the slow delay in my update but my 4 year old grandson stepped in the middle of my laptop that I had set in the floor. Of course it ruined it and I have been slow to get another one..

4 hours after my last post, I went to the motor, pulled the rope, and it hit a little. For the next 8 or 10 pulls, it progressively hit more and finally started. I put in on muffs and ran it for about 15 minutes- all seemed well. Took it to the lake the next day, started on first pull and ran great all day. I actually fished some, and motor started first pull every time I decided to change locations. I guess it was flooded or maybe the check valve issue mentioned by oldboat1 above. Thanks for the help and input !!