1996 115 ocean pro only starts at WOT

[FL175]

Let me start by telling you what I've done in the last to weeks.  First one day while on the water the motor would only get to about 4200 out of no where.  If the throttle was push more it would lag.  I replace the fuel filters and spark plugs and it ran great.  This weekend ran it to a friends dock with no problem.  Next morning went to surprise the wife for her birthday with a water trip and the motor wouldn't start.  It has spark and fuel, I took all the carbs down and cleaned them thinking it was a stuck float but nothing.  The only way it will start is WOT then it runs like crap for a min and then it will idle but not very smooth.  Even after its warmed up it won't start unless its WOT.  I'm leaning towards some type of ignition problem not??  I don't know where to turn next without buying a ton of parts and trying to replace one by one.  If you guys have any experience with these motors please chime in.  Thanks!!

Donny

[RickK]

Have you tried running it on a remote tank with fresh gas?  This will rule out a ton of items.

[FL175]

I have't tried the remote tank of fuel.  Once it is started it runs, not the best but there is more of a problem starting it.  It almost seems like it needs the spark advance to start.

[fitz73222]

Try the separate fuel tank with fresh fuel to isolate the main fuel system as root cause and see if it runs better. Is your primer bulb going flat when the engine is only turning 4200 at WOT? Once you conclude this isn't a fueling issue or it is, go from there. I'm leaning towards a bad coil pack. Your engine has two coils that provide ignition for 4 cylinders. One of them could be bad and you're loosing fire. They are behind the plastic cover in the rear of the engine. These coils do develop cracks and the coil can short to ground through the crack. Try running the engine on a flush and pull of each plug wire one at a time and hold the wire, with insulated pliers and see if the fire will jump to the plug when held about 3/8 to 1/2 inch away from the plug tip. Also look to see if the coil lights up and starts arching to the block through a crack or leaking wire or boot. Removing the wire from the plug makes the electricity find an easier ground path and may show the problem.

[Woodeneye]

Try the separate fuel tank with fresh fuel to isolate the main fuel system as root cause and see if it runs better. Is your primer bulb going flat when the engine is only turning 4200 at WOT? Once you conclude this isn't a fueling issue or it is, go from there. I'm leaning towards a bad coil pack. Your engine has two coils that provide ignition for 4 cylinders. One of them could be bad and you're loosing fire. They are behind the plastic cover in the rear of the engine. These coils do develop cracks and the coil can short to ground through the crack. Try running the engine on a flush and pull of each plug wire one at a time and hold the wire, with insulated pliers and see if the fire will jump to the plug when held about 3/8 to 1/2 inch away from the plug tip. Also look to see if the coil lights up and starts arching to the block through a crack or leaking wire or boot. Removing the wire from the plug makes the electricity find an easier ground path and may show the problem.

Damn! Thats some serious diagnostic advice right there. Well done that man.

[Adam927]

I had the same problem with a friend of mine's boat. He has a johnson 200hp 1999. It was the choke. There is a red valve on the choke solenoid make sure it is all the way open. If it is closed even a little it will do what your boat is doing. If that is not it then check for water in the fuel. This was also a problem that he was having.

[gwinnibarge]

One other thing to check is the shift interupter switch. For my 1998 ocean runner 150, the switch was stuck in the open position causing the right bank of cylinders to not get spark. It only activates when shift in or out of neutral. As I understand it, activating the switch reduces the initial torque on the transmission.

My engine still started, but it bogged down terribly and would not achieve higher RPMs. Ii found the problem by hooking up a timing light to each sparkplug wire. The fact that it was one bank tipped me off to the switch. Good luck.