2002 Yamaha 90 2-stroke won't stay running

[exmoore]

Here is the condensed story:
A few days ago I went
to run my boat. Been in the barn for about 2 months.
Idled rough. When I gave
gas, would start to go, but then would not get up on plane-kind of bogged down.
Would not get up to speed. Would cut off at idle, but restarted fine.


Two days later, never left the dock. Idled ok, but as soon as I put it
in gear, would cut off. Never got good pressure in bulb.

Here is what I
did:

Replaced below deck fuel lines from bulb to pickup tube on tank.
Replaced bulb, anti-siphon valve, fuel pump, quick connect at cowling. Installed
brand new water-fuel separator. Removed Yamaha fuel filter and connected line
directly to new fuel pump (since I installed fuel-water
separator).

Primed fuel lines with bulb, ran great in driveway for about
10 seconds (I guess until fuel in bowls burned up) then died. Not wont stay
running.

Pulled ned fuel filter off and poured gas into glass jar twice
- no water.

Running out of ideas. If I disconnect fuel line on carb. side
of fuel pump, I have no problem squeezing bulb and have fuel shoot out of fuel
pump.

I don't think it's a carb. issue, since it runs when I take it all
apart and put,it back together and prime everything...

Today, I plan to
disconnect fuel line on carb side of fuel pump and turn it over to verify that
new fuel pump is working correctly.

Also thinking about sticking fuel
line fuel tank side of bulb into a gas can with new gas to see if it runs.



Any ideas? What am I missing?

Thank you so much.

Erik

 

[exmoore]

Ran from a remote tank last night with new gas - ran perfect.
Then siphoned 5 gallons of the gas out of the boat and put it in another external tank and it rank rough and cut off a few times.
Color is darker - does not smell quite as strong.
Might be bad gas.
Gonna run it on the river today on an external gas can and see what it does under load.
AT LEAST, it's not the carbs!!
Erik

 

[guyjg]

Gas starts deteriorating after a few weeks. You need to pump out your fuel tank and add fresh fuel and use Marine Stabil w/each fill up.

 

[exmoore]

Ran it on the river yesterday. Ran pefect on new gas from external tank. Ran 'ok' on the five gallons of gas i siponed out of boat tank and ran from external tank. Cut off at idle - restarted easily. Almost convinced the gas is just starting to go 'bad.' Won't be totally convinced until I drain ALL of the gas out and refill the tank.