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Tan
Tan, MerCruiser Certified Technician
Category: Marine Electronics
Satisfied Customers: 10629
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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The boat runs fine -45 minutes then back fires, then

Customer Question

The boat runs fine for 30-45 minutes then back fires, then it will stall if it is run above in gear.I thought it may be bad gas but used clean gas in a gas can and it did the same thing.Any ideas on how to get the boat running properly?Please let me know.Thanks,Jon
Submitted: 8 months ago.
Category: Marine Electronics
Expert:  Tan replied 8 months ago.
Hello Jon.Could I get the make, model and serial number please?
Customer: replied 8 months ago.
It's a Rinker Captiva
Engine Model # *****
Engine serial # *****
Transom serial #0F688572Let me know if you need any thing.Thanks,Jon
Expert:  Tan replied 8 months ago.
Ok thanks. Have you checked the water separator fuel filter for water? Dump the contents of the filter into a clear container do you see separation? When you ran the engine on a different fuel source where did you connect the fuel line to the engine?
Customer: replied 8 months ago.
I will check the separator. The hose was from the gas tank into the new gas can.
Expert:  Tan replied 8 months ago.
Ok what we need to do is disconnect the fuel line # ***** from the water separator going to the fuel pump and get a short piece of hose and stick it in the gas can and run the engine. These water separator filters can become restricted over time from corrosion and cause fuel restrictions. This way we eliminate all possible causes of fuel restrictions. Leaving the fuel pump or carburetor as the problem if the issue still occurs. If the issue still occurs we need to do a fuel pump pressure test with engine running at 2000 rpms. http://www.marineengine.com/parts/mercury_marine_parts/static/img/COMMON/37620.gif Post back with questions and findings.
Customer: replied 8 months ago.
Ok I will by pass the water separator filter and see what happens. How do I do the fuel pump pressure test?
Do I need special tools?Please let me know.Thanks,Jon
Expert:  Tan replied 8 months ago.
Here is all you need for testing fuel pressure. http://www.tooldiscounter.com/ItemDisplay.cfm?lookup=MITMV5511&source=froogle&kw=MITMV5511&gclid=Cj0KEQjwo_y4BRD0nMnfoqqnxtEBEiQAWdA128uB92_KQBCGEXuDz-ausFkrMpkEUE6p6HYvhU1i4kMaAsEL8P8HAQ#The spec for fuel pressure is 3-7 psi at 1800 rpmsYou will have to make up some fittings to get this teed into the fuel line. You could just get to fuel hose barbs and some fuel line. Put hose barb in carb and fuel pump then use hose between the 2 fittings with the fuel pressure gauge.
Customer: replied 8 months ago.
I want to replace the fuel pump but am not sure where or which one I need can you help me with that.Please let me know.Thanks,Jon
Expert:  Tan replied 8 months ago.
Hi Jon.Here is a link to the fuel pump for your engine. # ***** you can go with either OE or aftermarket. One pump is as good as the other.http://www.marineengine.com/parts/mercury_marine_parts/sn/0F795639/457L100JS/1939_60 Please don't forget to positively rate my service as that is the only way I get credit for helping you. Follow up questions are always welcome at no extra charge even after you have rated on this subject. Thank you........Tan
Customer: replied 8 months ago.
Tan,I had the carburetor rebuilt and have not installed one before can I just bolt it back on, put if together and try it?Do you have pointers or suggestions that may help.Please let me know and thanks for your help.Jon

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