I'm stumped, please help. 1996 40HP force outboard

[moblizz]

Recently acquired a 1996 force 40HP 2 cylinder. I've searched on here and haven't been able to find an answer, so hopefully someone can help.

Here is the issue. Only bottom cylinder fires.

This is what I've done so far.
Compression is 130 - so not compression.
Tested for spark and great spark on both plugs. And swapped them and bottom cylinder only fires. - So not bad plugs
Swapped ignition coils and still only bottom cylinder fires even with upper coil - so not bad ignition coils
Put fuel into top cylinder and still no fire. **This one has me really stumped.
Removed carb and inspected reeds - they look fine.
Sprayed fuel into carb while motor was running (Bottom cylinder firing only) and still no change.
It's a single carb to run both cylinders and bottom cylinder is fine so I think carb is fine.

Please help. I don't want to throw parts at this thing. That gets expensive. Thanks in advance. Hopefully the great minds out there can offer suggestions.

 

[Nordin]

I have not work with these "new" Force engines so do not know them so well.
Think you have Mercury Thunderbolt ignition system and not the Prestolite system.
I think but not 100% sure that the magnets in the flywheel are glued.
Maybe some of them are loose and have moved.
If you have a timing light check that the spark for the top cylinder is 180 dgr from the bottom one that seams to work.
It should be 180 dgr from the other one.
As you describes it seams that top cylinder fires at the wrong time.

 

[racerone]

Does spark jump a gap of 3/8" on both leads , yes or no ?

 

[moblizz]

Thanks for replying. So one does and one doesn't. One jumped about 1/2 an inch, weakly, and the other had to be much closer but did spark. What does this mean?

 

[moblizz]

I think I need a tester. Adjustable ignition system coil tester. I think that's what you were asking. Not how far the spark plug would send the spark. I'll pick one up and report back.

 

[jerryjerry05]

If the bottom cylinder works?? The fuel pump is operated from the top cyl.
Check the pump and see if the diaphragm is bad???

 

[moblizz]

Tested just now and yes to jumps 3/8 on both leads. This 1st pic is at TDC. And second shows stator seems to have wires showing. Not sure if that could be causing the issue.

Does spark jump a gap of 3/8" on both leads , yes or no ?

 

[jerryjerry05]

IF??? you have spark on both leads and it's nice and bright/sharp. Then something else is the problem.
Recheck the fuel pump. Recheck the throat of the carb for obstructions(foam possibly).

 

[moblizz]

IF??? you have spark on both leads and it's nice and bright/sharp. Then something else is the problem.
Recheck the fuel pump. Recheck the throat of the carb for obstructions(foam possibly).

I had ruled out spark being the issue in the first post. I put fuel into the cylinder and it still wouldn't fire. Carb is clear as are reeds. I posted a picture of the flywheel at TDC and I believe it should be at 0 and isn't. I'll post it here too. Think that's causing the problem?

 

[Nordin]

Check the flywheel key.
I think it is shared.
Flywheel zero mark at zero mark at the timing plate
The top piston should be at TDC.
Check with a screw driver.

 

[jerryjerry05]

Pull the flywheel.