1990 Euro f3 engine problems

[Netdrop]

Ok guys. I need some help. I am a fairly decent home mechanic but do not know much about boat engines.

I have a malibu euro f3 that I just took out on the lake. I started it the day before with a water cooling and ran it for ten minutes no problem.

i took it on the water the next day and it started fine and ran for 30 min at full speed. then it just suddenly died and would not restart.

It has fuel but somehow I lost the gas cap if this matters?

Everything I have read so far leads me to think this is a fuel filter problem.

Engine temp was fine and at about 150.

This is a 5.7 L Mercruiser with a 4 barrel card. Not sure what carb. Please help!

[WakingMeHappy]

Lost your fuel cap? No telling what could be in the tank now. Add a fair amount of Stable and/or Sea Foam. You can get both at most auto stores. And yes, change the fuel filter regardless.

[Shine]

Could be several things. Start simple with the filters and move from there. There is a small inlet filter in the front of your carb in addition to the canister/element type. Other things to check would be the wiring to your key switch behind the dash (intermittantt shut off could be a loose wire). Check the cannon plug to the engine. Check any electrical connection for tightness. Use your judgement on replacing the all the fuel (if it could be contaminated with water, dump it).

Does the engine turn over and just wont fire?

No turn over at all?

Is there fuel at the carb?

[Woodski]

The carb on your Mercruiser is a Weber carb, you can find it etched on the body. It is the same as either an Edelbrock or Carter AFB, both which are pretty common and diagrams for them are available on line.

Unless you are very confident that no contaminants, mainly water, got in the system I would suggest draining the fuel system and putting in fresh fuel. That would include the lines, filters and carb. A good place to start would be the water separator, see what is in there and that should give you a good idea of how deep to go.