74 johnson 70HP 3cyl tri-carb engine-WHAT COULD IT BE :(

[SeaRay Seville]

Ive been fighting this for a year, when I first got it, it would run on all 3 randomly then kjck out to 1cyl only. Did the easy stuff: new tank, all new fuel lines and fittings, plugs, same result. tested compression good at 125 in all holes. New parts include Timer Base, all 3 coils, Rectifier, Stator, Power pack, overall check of all engine wires grounds wiring harness etc. If I shoot starting fluid in the top two holes they'll fire, pull fuel lines to those carbs and gas sprays out but when I pulled carbs they were dry in the bowl and the plugs are clean and dry like they were never ran? how can it not be getting gas??? could the spark be weak enough that it runs on starting fluid but not gas??? carbs look brand new exhaust gasket is good reeds look perfect in all holes and are not cracked or stuck, floats are not cracked or leaking, im ready to burn it and walk away...

 

[boobie]

Pull the float bowl drain plugs, pump the primer bulb and see if you're getting any fuel.

 

[Faztbullet]

If you have the wrong float bowl gasket fuel cannot pass to the carb body or if float istalled pside down needle will never allow fuel in...

 

[SeaRay Seville]

It randomly runs fine on all three cyls, even skiing or tubing and like a light switch will cut out to 1. Usually runs on just one but its totally random. Really seems like a gas issue as the top 2 carb bowls came off bone dry and the plugs looked new last time i pulled it all. Plus it fired the top 2 right away with staring fluid so i dont think its anything elecrtical. However i did read the ignition switch can cause this cut in/out issue, anyone ever heard of that?

 

[Silvertip]

If the top two carbs are bone dry fix the problem. It is not electrical. Inlet needle and seat or float adjustment/hangup is the issue.