1976 200hp Johnson Power on 2 Cylinders

[jaybird82]

Hey everyone.
I have a baffling issue I hope someone can help with. I had someone rebuild this outboard for me. It's been machined .030 over on 4 of them and .040 on two others. It has it's timing set correctly, has 110 compression in all 6 cylinders, and spark on all six. The issue is only the middle two cylinders are providing combustion. Changed plugs, moved the plugs from the two cylinders to other ones and the problem doesn't follow. So it has everything the engine needs, spark, fuel, timing are all correct. I read something on troubleshooting a similar issue on cdi for Outboards with a S.L.O.W feature but is this engine to old to have that tech? I'm completely lost as to what it could be at this point.

 

[Faztbullet]

Upper and lower carbs not supplying fuel

 

[jaybird82]

both carbs were cleaned and rebuilt. Both fuel pumps are newly rebuilt too. Plugs aren't dry when taken back out of the motor

 

[CaptnKingfisher]

both carbs were cleaned and rebuilt. Both fuel pumps are newly rebuilt too. Plugs aren't dry when taken back out of the motor

Something is wrong with the information youve given. If it's got fuel, spark and compression it'd fire. How are you checking spark? I'd recommend measuring spark strength with an adjustable tester. If spark is good then I suspect the carbs even though they've been rebuilt.

 

[Faztbullet]

Spray some fuel mix into carbs while cranking..if it hits its carbs if not look at ignition.

 

[racerone]

Make sure wires FROM the CDI modules are going to the correct coils.

 

[Skylar.Hale]

Based off the information given and other comments I would have to guess it's a mix-up in the coil wiring. If you have fuel, air, compression, and spark you will have fire. Only other issue could be timing or something timing related.

 

[jaybird82]

Something is wrong with the information youve given. If it's got fuel, spark and compression it'd fire. How are you checking spark? I'd recommend measuring spark strength with an adjustable tester. If spark is good then I suspect the carbs even though they've been rebuilt.

Using one of those multi-wire spark testers. It's jumping the gap on all six. Maybe it's not enough fuel

 

[jaybird82]

This outboard also has two fuel pumps. They were both rebuilt, but I'm wondering if something is wrong with one of them preventing enough fuel.

 

[racerone]

There is no S.L.O.W. system on your motor.---There is not much that can go wrong with those fuel pumps.----Unless hoses are not routed incorrectly.----Yes you have spark on all 6 leads !-----But are they timed correctly as in are the wires FROM powerpacks going to the correct coils ?----Up to you to investigate this as I can not see , hear or feel your motor !----I say it should be easy to figure this motor out.