'97 50hp Johnson HELP no fire on top, and bogs down

[bullcity101]

All,
Thank you in advance for you advise.

I am at a place where I do not know where to go from here.
I went out to start the outboard after a few weeks and noticed a rough low idle, my first instinck was bad fuel. I replaced the fuel and still a no go. I went to rev the engine (on flusher so only what the neutral limiter would let me) and it would bog down and die if I didn't bring it back to idle. While running, I went back to the plugs and pulled the top plug boot and there was no change in how it was running. Put that back on, pulled the bottom and it quit. Which lead me to believe its only running on the bottom cylinder. I pulled the carbs, cleaned the jets, adjusted the floats. I sprayed and blasted with compressed air. Put them back on and still the same sysptoms. I then checked fuel flow by pulling the line attached to the carb while running and it has good pressure. I then went to square one and checked compression, 118 on the bottom and 120 on the top.
I know it has spark, I know it has compression. So I even sprayed fuel in the top carb while it was running and it had no change.
Fuel, air and spark...I DONT GET IT.

Also, I had noticed that the water that escapes from the exhust is brownish...Does that have any meaning???? '
Please HELP!!!!

John

 

[Daviet]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

If you are sure that you have proper spark, jumps a 7/16" air gap, try swapping the plugs and see if the miss moves.

 

[bullcity101]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

Right on, I will try that. I feel certain that both plugs are properly firing but defintely worth a shot.

 

[bullcity101]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

anybody else have any ideas??

 

[Will Bark]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

Did you pop the welch plug out of the carb and clean the idle circuit holes out properly? How did you check the spark? Holding the plug against the block to see if sparks doesn't tell you anything except that it will spark in the open air; must jump the 7/16th gap on a spark tester. Good luck

 

[bullcity101]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

Wanted to give an update:

I switched the spark plugs, pulled both carbs, again and cleaned. Now, it will only run when given throttle anything close to idle it will die. It will run all day with throttle in neutral. When it dies, i have to pump the bulb... It seems as though it is running on both cylcinders... I think I will go ahead and replace the spark plugs as because when I switched them from top to bottom it changed the way it was running. But that also could have been me spraying and blowing out the carbs....

Will Bark, Where exactly is the welch plug? My manual doesnt mention that.
Thanks and any help would be great!

 

[bullcity101]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

update.
put new plugs in, and cleaned both carbs again.... still runs rough, and only when given a little throttle... it is only running on the top cyclinder for a while and then the bottom kicks on after a few secs...like 10. runs runs runs dies after a minute or so. The bulb is soft. I have to prime the bulb to get it to start again. then the same thing repeats. I also noticed that the prime selonide red lever was in the "off posistion" as my manual states. I turned it to the on posistion and it won't start at all! I have to turn "off" to get it to start. hmmm... Anyone have any opinions?

It seems to me as I may have a fuel primer selonoide/fuel pump issue.

 

[Daviet]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

Will it continue to run if you keep pumping the primer bulb, thinking a defective fuel pump.
You could also use a timing light to check the spark while the engine running.

 

[Will Bark]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

Thw welch plugs should be the little silver plugs located on top of each carb; underneath them are the holes for the idle circuit. If this is not correct someone will chime in with a correction.

 

[bullcity101]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

Will it continue to run if you keep pumping the primer bulb, thinking a defective fuel pump.
You could also use a timing light to check the spark while the engine running.

I know it is getting spark, as I have had a timing light on the #1 to check for timing so both are good on that front. I have started to squeeze the bulb when it was dying and all it did was bog down. I will try again. What does the primer seloniode do and what oreintation should the red lever be in. I thought it was supposed to be parallel with the pump itself and in the direction of the pump. It will only run when it is the oppisite now and then die after it has run all the gas out of the floats ( i assume). I don't understand how I can go from where I was to start this thread, where it would run at only idle on the bottom cyclinder, to now where it will only run with throttle on the top cylcinder and after 30 seconds or so it will run on the bottom and then bog down and die.....ugh.

Will Bark: All is see on top is a black top where there are 4 screws holding it down. it has the place where the idle mixture screw is and where the line for the primer. No silver plug that I can see.

Anyone?

 

[Will Bark]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

That's a carb I'm not familiar with so Daviet or Boobie will have to chime in on; They may ask if you have checked to see if the tops are plastic and have you checked to see if they are warped to where they are leaking air.

 

[Daviet]

Re: '97 50hp Johnson HELP no fire on top, and bogs down

The primer solenoid takes the place of the choke in the carburator. When you turn the key to the on position and push the key IN, the solenoid injects fuel in the manifold just behind the carburator body.
If the red lever is turned over the solenoid body it is in the auto position and will inject fuel when the key is pushed IN. With the lever turned 180 degrees it acts like a manual choke and lets fuel flow to manifold. You need to have the primer bulb pumped up firm for the solenoid to work properly in the manual position.
http://forums.iboats.com/showthread.php?t=305323