Re: 1988 Johnson 150 - Engine wont star, need some advice!
There are 3/8 fuel lines at each carb, follow them from carbs back, they will all run to one single line, and then to the fuel pump.....do you still have the vro pump?
Do u have a timing light? The type you use for a vehicle? If you do, use it to see if you have spark on all cylinders, on my motor, i used this method, and was able to tell i had weak/intermittent spark on the starboard side.......my problem was the stator....my motor would also run rough at about 2500 rpm in tge water under load, in neutral it ran great. ...also, dont be afraid to change out the spark plugs. Fuel and/or ignition problems can foul a plug quick, youll end up fixing your problem and youl never know it if u have a fouled plug.....their cheap for that motor, so replace them, see what you get.....but try the spark test first.....if you got great spark, and it still runs bad, could have fouled a plug.......brand new plugs can foul at the drop of a hat, so just cause their new, doesnt mean they are good......
I just noticed you asked if it would run rough if not all cylinders were firing.......mine idled so great i thought it was a fuel issue, but if fact three cylinders were firing weak ar not at all....,sometimes a spark issue will not be noticed if your not in the water and under a load (boat in gear and throttle applied.).....
