50 HP Surging Problem

[johnrmclean]

I just started having a surging problem with my engine at speed yesterday while on my way back in for the day. To stop the problem i had to pretty continually keep pumping the fuel bulb to keep a stead supply of fuel going to the engine. Today I replaced the bulb but it did not make a difference. I'm pretty sure I replaced the fuel pump diaphragms when I rebuilt the carbs last fall. I have 2 steel 5 gallon tanks. Today, with the tank I was using yesterday when this problem started, which is about 1/4 full I could not get the engine to run up to speed at all. At full throttle it would hardly move and I assumed it was not getting much fuel. I immediately switched to the second tank that was full. Right away I thought the problem was solved and it ran ok but after about 10 minutes it also started surging near full throttle unless i pumped the bulb again. I backed it down a bit to say 3/4 and it ran ok. On the way back in an couple hours later with about 1/2 tank left it again started surging. I had to keep pumping the bulb to make it back without surging. Now I'm wondering if there are issues with the fuel tanks? Anyone else experience this? Any thoughts out there??

 

[Bosunsmate]

Re: 50 HP Surging Problem

Sounds like your pump may have gone again.
But try priming your motor and then remove the quick disconnect where it joins to the engine. Check it holds the primer firm for a few minutes. If it does hold it then reconnect the disconnect and see if it holds the prime in the engine, if not look for a leak in the engine bay.
Also check your air vents a clear on the tanks.
Sometimes the pickup tubes in them get leaks which can cause this problem as you end up sucking up air with the fuel

 

[fireman57]

Re: 50 HP Surging Problem

Usually if you have to keep squeezing the primer bulb to run it means your fuel pump is bad.