1996 johnson 70 hp

Engine boggs down at 2100 rpm and dies. In neutral will rev to 5000 wil no cut out, place in gear and dies at 2100 or above. starts, idels, compression checked, fuel lines replaced, carbs cleaned spark good, plugs replaced, fuel filter cleaned, fuel pump replaced. runs fine at low speed, dies when throttle is pressed. My mech. is stumped, ? could this be electrical?, in neutral runs fine, engaged dies.

Re: 1996 johnson 70 hp

What are the compression numbers?
Check powerpack mounting plate bolts, pack grounds thru these bolts.
Check the power pack wires for bare spots.
Check all pack ground wires.

Re: 1996 johnson 70 hp

Revving in neutral = bad idea. Besides which, it's pointless; as you now know from personal experience, you can't judge how it will perform under load, by running it unloaded.

Yes, post the compression numbers, please.

If it dies when you throttle up, you're losing more than just one cylinder.

Do a spark test with an inline spark tester gapped at 7/16". report your results.

How did you know the fuel pump was bad?

Is the fuel line holding pressure?
How old is the gasoline? Check the tank for water and debris.

Unless by "carbs cleaned" you mean "removed, disassembled, soaked overnight in carb cleaner, reassembled with new carb kits, reinstalled and link & sync'd", then you aren't finished with the carbs.

Is the timer base moving smoothly without sticking when the throttle is advanced?

Sounds to me like it needs link & sync, starting from step one.

If that doesn't help, take the carbs apart and make sure the floats are right side up, and the height is set correctly.

Re: 1996 johnson 70 hp

Thanks for the reply. I am two hours from the boat and mechanics, communicating by phone and e mail. New power pacs have been ordered. I will get a clearer understanding of "carbs cleaned", most likely they were only sprayed with cleaner. I will print your response and take it to them this weekend.