1996 115 SW Series - running out of fuel

Seems my 115 may have a bad bulb but would like to explore your minds for concurrence and/or other issues that my be plaguing this engine.

Here is the latest issue: while running at idle she will start to sputter then eventually die ( a minute or two) while in gear (under load), if put under excessive load (full throttle) she dies quickly. But if the bulb gets pumped during idle she will stay running, if gets pumped under full throttle load it will sustain for a few more seconds then shuts down.

Prior to today : if idle for long time (through coastal river no wake zone - manatee areas) when placed under excessive load (full throttle) she would bog down and die out, pump the bulb and she was ready to get up and run till next long period of idle..

So in July of last year I replaced all fuel lines (not the bulb, bulb was done in 2008), fuel pump, soaked carbs for 24 hours in solution and general tune up. Had no effect on the 'prior to today' issue.

Think the bulb will fix the issue or do I have multiple problems?

Thanks,
jsalty

If you can pump the bulb and keep it running that suggests a fuel pump problem or a fuel restriction. Throw a bulb on there for good measure but it probably won't fix the problem. Get a good one not a cheap one. I'm thinking this engine has a white cone shaped fuel filter between the carbs. Remove the airbox on the front of the engine and find this filter. You can screw it off with your fingers and see if it's contaminated. I have found these filters to cause problems like this many times. Easy fix. If you have a fuel pump problem with the VRO you should take it to the shop. These things have many parts and are difficult for a consumer to service or repair. I hope it's the filter.

what is the 'VRO' mentioned above?

The engine mounted fuel filter is a clear bowl type with a fine mesh screen basket in it. Seems to be about 1/2 full of fuel.

The VRO is the fuel/oil pump. It mixes the oil into the fuel so you don't have to. It black and has the fuel and oil hoses going to and from it. It's located at the front of the engine behind the aibox. If your fuel filter is only half full then you might have a problem with fuel supply. They usually stay full or almost full. Make sure no part of the filter is cracked or leaking then work your way back from there carefully inspecting every connection and fuel system component. You're looking for a possible air leak. An air leak can be hard to find because sometimes the leak is so small that fuel might not leak out but when the engine is pulling fuel it can pull air into the system like drinking through a cracked straw. Repair or reinforce any connection that is questionable. Does your bulb suck itself flat?

I do not have a VRO then. My oil does not mix with the fuel until after the crabs. I have a seprate pump for fuel amd oil. Engine is 1996 115P saltwater series.

The bulb does not suck itself flat.

Removimg anti siphon at tank connection and cleaning pickup tube in morning.

I'm sorry, I thought you had a Johnson. I read so many threads I got mixed up. That's good though, your motor is simple. Before you go digging for the anti siphon valve you might check your fuel pump. It's easy to get to and easy to test. The pump is bolted to the side of the crank case near the fuel filter. Some guys check them by disconnecting the outgoing line and cranking the engine. That shoots fuel everywhere and tells you if it pumps but not how well. I like to remove the pump and blow through it. You should be able to blow easily through it in the direction on the fuel flow but not the other way. If you can blow backwards through it (with your mouth) the valves are leaking or worn. You might be able to blow a tiny bit of air through it if you blow real hard but a new or good pump will not allow any backwards flow. A fuel pump is very easy to replace and shouldn't cost but $50 for a real Yamaha part. Yamaha engines hate aftermarket parts. I NEVER use any aftermarket parts on a Yamaha. The half empty fuel filter comes to mind. It could mean a fuel restriction (anti siphon valve) but to me suggests and air leak. If you inspected the fuel system and especially the connectors and find everything to be in top condition then it's time to check the pick-up tube. I must warn you, the bung in the top of the tank is almost always very tight or seized, be cateful not to twist it off at the base. Many times I have removed the check ball & spring from the antisiphon valve by punching it out with a large phillips head screwdriver. Doing so will reduce the restriction caused by the ball. The pick-up tube could be cracked, it's not uncommon. If it's cracked it almost always cracks in the middle. That means the boat runs fine with a full tank but starts sucking air when the tank gets down to half. Pulling the pick-up tube is generally reserved for when other possible leaks of restrictions have been checked and verified to be in good condition. Reason being, it's a knuckle buster of a job in most cases and if you're not very careful you might twist it right off, then you have a problem. First loosten the thin nut at the base of the bung, spray it with plenty of lubricant, and carefully twist it back and forth to get it loose, carefully.

I have already pulled the anti siphon and loosened the 90 for the pickup tube. I have disconnected, inspected and reconnected all boat side connections, filters and hoses. After I finish the inspections and modifications on the tank hardware I will turn my attention to the engine side of tje fuel system.

Thank you all for the helpful information and advice. I will update tomorrow after I have a chance to get her back together and tested.