1996 5.7 Mercruiser cuts out under load or full throttle Please Help ASAP

Ok I have a 21ft 1996 Sylvan with the Mercruiser 5.7L 2 BBL Merc Carb

Ok It would run great at first then when it heated up would lose fuel or bog out after a couple sec of full throttle or even if left at 2200 rpm for a min or so. It's weird it just fuel cuts off but will stay running if you put it in neutral in time. What I have tried so far.

1- Rebuild The Carb- New float adjusted float at 9/16 upside down float hanging 1-3/32 per the spring loaded needle valve. I did try to adjust at 3/8 upside down and 1- 3/32 hanging seemed worse. kit did not come with i believe the power valve so has original one and the spring setup that looks like hits it also untouched.

2- New water/fuel Seperator

3- New Fuel Pump original mercury replacement.

4- can blow through the vent to the tank no problem .

I am lost tried local marina where we keep boat no luck they cant look for 2 weeks

Any help or mechanic in Monticello Indiana Let me Know ASAP

Re: 1996 5.7 Mercruiser cuts out under load or full throttle Please Help ASAP

Have you verified a good fuel system before the filter housing yet? You're throwing the lamp away before you verify it's plugged in. Check from your source. Pickup tube, anti syphon fitting, hose condition (inside) If you have access to a portable fuel tank, try hooking your filter housing up to a completely different fuel source so you can narrow down the problem. Most likely you'll find the pickup tube is in bad shape or the anti syphon valve is stuck. Hope it helps, and be sure to return to your post once the problem has been repaired, there are a lot of unfinished threads are here that are useless as I'm sure you have seen. Good luck to you.

Re: 1996 5.7 Mercruiser cuts out under load or full throttle Please Help ASAP

97proline2810 said:

Have you verified a good fuel system before the filter housing yet? You're throwing the lamp away before you verify it's plugged in. Check from your source. Pickup tube, anti syphon fitting, hose condition (inside) If you have access to a portable fuel tank, try hooking your filter housing up to a completely different fuel source so you can narrow down the problem. Most likely you'll find the pickup tube is in bad shape or the anti syphon valve is stuck. Hope it helps, and be sure to return to your post once the problem has been repaired, there are a lot of unfinished threads are here that are useless as I'm sure you have seen. Good luck to you.

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Where would the anti syphon be located ? I felt the hose going to housing to see if it may be collapsing seemed ok .