92 Nitro 190dc Owner
Well-Known Member
I've rebuilt all 6 carburetors, installed new OEM Fuel Pumps, Fuel Pump pressure checks out at @ 2psi - 3psi. and holds it at that pressure, the vapor pump holds a vacuum, the vapor separator float is set correctly, the needle is not stuck (assume it's seating correctly). Fuel lines are not kinked or restricted and no cracks when flexed. The primer bulb pumps till it's firm and stays that way. Carburetor jets are clear. The engine starts right off, but will not run for long (a minute or two or less). I've run the engine from a separate tank with fresh fuel. I've used clear tubing for the fuel line to look for air bubbles. No air bubbles. My assumption is that the engine is not getting fuel, but don't know where else to look. The engine is a 1992 150hp Evinrude. It was originally a VRO set up, but changed it a couple of years back to two carburetors using premixed (50-1) fuel in the tank, because the VRO kept failing on me. Any thoughts on where to look next or what other tests I can run?
Background: Earlier this year, the outboard refused to start or run while out on the water. Discovered one carburetor was leaking quite a bit of fuel. Disassembled the carb and discovered that the gasket didn't quite align with one edge of the carb bowl. The gasket would not stay where it would provide the proper seal. I was finally able to keep the gasket aligned with the carb bowl by using gasket sealant that acted as an adhesive. Re-assembled the carb, pumped the primer bulb to build pressure and the leak stopped. However, fuel pressure in the fuel lines dropped very quickly. Of course, the outboard would still not start or run. I disassembled both aftermarket fuel pumps, but nothing stood out to indicate an issue. I decided to buy new OMC OEM fuel pumps to replace the aftermarket fuel pumps. I installed the new fuel pumps and the fuel system is now able to hold pressure. The outboard will start, but will only run for a brief time. I suspect the outboard is only running from the fuel in the carbs. Therefore, the engine is not pumping fuel to the cylinders. To me, this implies that the engine is not creating a sufficient vacuum to cause the fuel to flow to the carbs, since I've checked everything from the fuel tank all the way to the fuel entering the engine.
Background: Earlier this year, the outboard refused to start or run while out on the water. Discovered one carburetor was leaking quite a bit of fuel. Disassembled the carb and discovered that the gasket didn't quite align with one edge of the carb bowl. The gasket would not stay where it would provide the proper seal. I was finally able to keep the gasket aligned with the carb bowl by using gasket sealant that acted as an adhesive. Re-assembled the carb, pumped the primer bulb to build pressure and the leak stopped. However, fuel pressure in the fuel lines dropped very quickly. Of course, the outboard would still not start or run. I disassembled both aftermarket fuel pumps, but nothing stood out to indicate an issue. I decided to buy new OMC OEM fuel pumps to replace the aftermarket fuel pumps. I installed the new fuel pumps and the fuel system is now able to hold pressure. The outboard will start, but will only run for a brief time. I suspect the outboard is only running from the fuel in the carbs. Therefore, the engine is not pumping fuel to the cylinders. To me, this implies that the engine is not creating a sufficient vacuum to cause the fuel to flow to the carbs, since I've checked everything from the fuel tank all the way to the fuel entering the engine.
