[Edweird]

I have a 1999 Yamaha OX 66 Salt water series II 250.

Runs excellent at low speeds and above mid range, but when you open it up, it shuts off. Just stops.

Start it back up and it runs fine, but the same thing will happen. Any suggestions?

[robert graham]

sounds like a fuel delivery problem. start back at the tank,vent screw, fittings, hoses, bulb, filter, fuel pumps. could be a fuel tank vent or probably a fuel pump/pressure issue. none of these are very expensive to replace/repair. Good Luck!

[amasi]

Time to clean that VST tank Fillter(screen)!!

I had almost same problem and then I get answer from some Goodman at this sight.

you open that motor Cover
you can see VST tank (front to right side)
3 screw holding that VST tank 2 top 1 bottom.
unscrew that all screw, then you can see 2 low presure valve (black square)
1 on top 1 on bottom change that to new,

and open the VST tank with around 10 little srew
(make sure drain the VST tank there is little valve, bottom of VST tank,)
you can see that round plastic tube, turn unclock wise and pull
that's the screen fillter.you have to change or clean

so you need 2 LPV and 1 VST tank fillter and VSTtank gasket.

Good Luck!!