-Surging-after-20-min.-run time

looseplay · Aug 13, 2011

I have a 1996, 24ft. stingray cuddy cabin. It has a 5.7 mercruiser with a 2 barrell carb. The engine runs and revs fine with no load. Once a load is placed on it will run perfect 15-20 min then start to surge. I can back it down to 2000rpms and it will limp home just fine. I have rebuilt carb, had a valve job done, replaced coil and dist. Compression is good in all 8 cylinders. A while back I placed a electric fuel pump on it. Could this be a fuel starvation or just bad fuel? Any suggestions. Thank You

looseplay · Aug 13, 2011

Re: -Surging-after-20-min.-run time

I also replaced dist. with this one PTXD200800 Pertronix Ignitor II Marine Billet Distributor. I read on another thread that the coil hould be getting 12v. I just tested and I am getting 11.6 at pos. and neg. could this possibly be the prob. tks,

cr2k · Aug 13, 2011

Re: -Surging-after-20-min.-run time

Check your fuel pump output. Your fuel tank vent and your fuel hose and filter.

jonirish · Aug 13, 2011

Re: -Surging-after-20-min.-run time

Bad fuel. Siphon the tanks and first run Seafoam and fresh gas then run Sta-Bil Marine ethanol formula and fresh premium always.

looseplay · Aug 14, 2011

Re: -Surging-after-20-min.-run time

Any tricks on taking out the anti siphon valve? I can not see where it attaches, I can only feel it. Does it just loosen and come right out of tank- very tight spot

looseplay · Aug 14, 2011

Re: -Surging-after-20-min.-run time

I know tha is the line right next to the fuel fill line, can not see, does it just have hose clamps. loosen and just pull off.

thumpar · Aug 14, 2011

Re: -Surging-after-20-min.-run time

Just open the fuel cap to make sure that is the problem. I wouldn't run with the line off.

looseplay · Aug 14, 2011

Re: -Surging-after-20-min.-run time

Will do, I would like to check the anti-siphon though, but am not sure exatly how to pull i out,

looseplay · Aug 16, 2011

Re: -Surging-after-20-min.-run time

I want to drain the gas and check the anti siphon valve also, can some one tell me how to get the hose out, I can not see in the small area. What is best way to get the gas out

capecodder116 · Aug 16, 2011

Re: -Surging-after-20-min.-run time

failed to read you already rebuilt the carb....sorry. I had the same symptoms and corrected it with a carb rebuild.

Rellik546 · Aug 17, 2011

Re: -Surging-after-20-min.-run time

i have a plastic tank, there is a thin hex nut flush against tank. your are not suppose to unscrew it, instead use channel locks to hold it in place while you unscrew the anti siphon valve from it. it should take quiet a bit of pressure to get it to budge, i thought that i was about to break it right as it started to loosen. make sure you put it back on tight too.

looseplay · Aug 19, 2011

Re: -Surging-after-20-min.-run time

Thank you, I wil try th today, I guess if I get tht out I will use an electric pump and pump the gas/ maybe water that is in tank.

looseplay · Aug 21, 2011

Re: -Surging-after-20-min.-run time

Ran today on external tank and all ran good. Looks gas related, tried pulling anti-siphon with no luck, any other tricks to get this out with such a small space. I think once I get it cleaned, tank emptied I will be back on the water again. thanks

jonirish · Aug 22, 2011

Re: -Surging-after-20-min.-run time

I never bothered with the anti-siphon valve. I just stuck a hose in the filler to the bottom of the tank and suck started a siphon to a container on the floor below trailer level and removed close to all of the gas. then I dumped a can of Sea-foam and 2oz of Sta-bil Marine ethanol formula and filled to top with Super. Have made 15 trips now, no problems.

-Surging-after-20-min.-run time

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