Someone else posted this question here in 2008 but no solution was posted. I have twin 250 Yamahas with roughly 600 hrs on each. This weekend the 5 amp fuse in each started to blow. One of the guys on the boat had to hand pump the bulb every few seconds to keep us going. Note that both motors have the identical problem and the motors run perfectly when hand pumping the fuel.
All day Sunday we checked the fuel and changed the filters...no help. I couldn't measure the fuel pressure to see if the pumps are bad, but no way both are bad at the same time.
The only possible solution I have heard from a serviceman is that the battery could cause this problem. Apparently the ground is common and if one battery is grounding (and I do have 1 weak battery) it can send a positive charge through the negative line. The obvious fuse to blow would be the 5 amp one. I can't check this for a week or two until I can get back to the boat...so I thouht I'd ask for anyone else's experience.
All day Sunday we checked the fuel and changed the filters...no help. I couldn't measure the fuel pressure to see if the pumps are bad, but no way both are bad at the same time.
The only possible solution I have heard from a serviceman is that the battery could cause this problem. Apparently the ground is common and if one battery is grounding (and I do have 1 weak battery) it can send a positive charge through the negative line. The obvious fuse to blow would be the 5 amp one. I can't check this for a week or two until I can get back to the boat...so I thouht I'd ask for anyone else's experience.
