Yamaha 250 Four Stroke Won't Start

[Windfall]

I am running twins and neither will start. I was operating the boat on Saturday, and it was running perfectly. I went to turn around and both engines shut down and would not re-fire. I have worked on it for two days now and neither will start. The port engine is turning over but it will not fire up. We took out the plugs and they are firing. We also tested the batteries and they appear to be fine. The starboard engine is locked up and won't turn over. We took the plugs out of it and tried to turn it manually but it is frozen. Anybody have any clues as to what could have happened to cause such a failure at the same moment to two engines?

 

[bernieb]

Re: Yamaha 250 Four Stroke Won't Start

My first thought is somebody is out to get even.I would stop using your present gas untill your sure its good. It's strange that both engines are down,but just to be sure clean battery cables and have batteries checked at local parts store.

 

[rodbolt]

Re: Yamaha 250 Four Stroke Won't Start

drain the vapor seperators and check them for water. inspect all the filters for signs of water. if water made it to the VST tanks it will cause a severe rust problem. the injectors will spray water just as well as fuel.