cant get my 9.9 to start

[hijinks]

ive got a mercury 9.9 two stroke from the 80's. its always been a great running motor until this year. now i cant get it running. it will fire and stay running if i spray carb cleaner, so its getting a spark. the fuel is new and there is good fuel pressure into the motor.

i unscrewed the cover of the fuel filter, at least thats what i think it is. its plastic reservoir with a filter/screen on the inside. the fuel line goes into the top of it and then goes out of it into the carb. it was full of gas. however, i tightened it as much as i possibly could but it now bubbles when i squeeze the fuel ball. i didnt see a gasket, not sure what to do about that.

the salmon are in and i want to get after some! thanks for any help, i greatly apprecaite it.

 

[guyjg]

Check for loud snapping blue spark from each cylinder. If it is there then rebuild the carb.

 

[hijinks]

i checked and each plug is snapping pretty good.

what about the fuel filter? i took it apart again and cleaned it all up and put it back together and it still spits and bubbles when i pressurize it with the fuel ball.

how straight forward is it to clean up a carb on one of these? i do it with my chainsaws and stuff but i havent ever worked on this boat motor, its definetely appears more complicated.

 

[guyjg]

i do it with my chainsaws and stuff

you can do it. YOUTUBE is full of boat engine carb rebuild videos.

 

[galamb]

You probably lost the flat (o-ring) washer that goes with the fuel filter and now you are sucking lots of air which could account for your issues.

There is a little rubber washer that goes on the rim of the (cup) of the fuel filter. It falls off every time you unscrew the fuel filter. It's kinda a dull red in colour and you can never find it if it hits the ground (No, I have done this a few dozen times myself over the years ).

It's #3 in the diagram below - merc part 25-897536 (they call it a "fuel filter seal"), costs a little under 2 bucks (I have about half a dozen spares hangin' in my shop).

Stop by any Merc dealer and they will fix you up...