Running on one cylinder

I have a 2003 Johnson 2 stroke running one one cylinder. I have replaced spark plugs and checked spark with a spark tester set at 7/16" gap. It jumps that gap easily. Both carbs have been rebuilt and are good. Removed reed valve assy. and found no problem. VRO checks out. Even if I squirt fuel in the cyl. that isn't working it makes no difference. Swapped carbs from top cyl. to bottom cyl. Didn't make any difference. Checked pulse limiter and it seems to be working properly. I pulled cyl. head to check piston and cylinders even though I had 140 psi on each cylinder. Everything looked good.Tried to put pressure on crankcase thru pulse limiter but I couldn't build up any pressure. According to manual it should pump up to 15 psi. I checked upper crankshaft seal and it was good. Is my only option is to pull power head and check lower crankshaft seal?

What manual and where was the piston when you applied the pressure ?----Top of cylinder / bottom / not sure where it was ?

I found it on You Tube under checking crankcase seals on outboard. Not sure where pistons were. I know they should be at TDC when checking but pistons can't be TDC at same time.

Oh I see.-----But you are aware that your motor has 2 separate crankcases.------So you would only be concerned about the bottom piston.-----If the intake and exhaust ports were OPEN on the bottom cylinder you could never ever see any pressure on your gauge.

You got into this pretty far, brother. You can check spark timing on affected cylinder with a timing light. What could be happening is your electronics controlling spark are gunnyfunker. Did it happen all at once, or while it was stored for the season?

Boy do I feel like a dummy! I didn't even think about each cylinder being isolated from each other. Thanks

I bought this boat "as is". Yes it had been setting for a while. Good thing I didn't pay much for it. After I fired it up it wouldn't idle so I started checking things out. I'm sure the timing is off but don't know where to start. I don't think it will idle long enough to check timing. I ordered a repair manual for it. Maybe it will help. I really enjoy working on this outboard just wish I knew more about them.

Could be the spark is firing the same time as the other cylinder. There is no way it could fire the affected cylinder if spark is happening at the bottom of the stroke. Just hook a timing light to a battery and the affected cylinder plug wire. Put a mark or a piece of tape on the flywheel so you can see it line up with the reference pointer when the "dead" cylinder's piston comes to the top. This, in other words, is TDC of the "dead" cylinder. When you crank it over, you will not be actually starting it, aim the timing light at your reference point. It will flash when triggered by the spark . If the flash is nowhere near your TDC Mark, more specifically 180 degrees off, then we have a problem to trace down within the ignition system. I, or another tech, can direct you from there. Will need model # then......could be trigger, or power pack, I really don't suspect the stator, but we can check using some ohms and possible use of a DVA meter which measures electrical pulses. Soon, Kenny, you will have your own diagnostic and repair shop.

Thanks timguy. I had to go out of town so when I get back I will check her out. Thanks for your knowledge. I will let you know what the problem ended up being.

Great, gotta start simple on this stuff, it usually isn't really complex. Gotta look at history on it, gotta ask simple questions.