Backfiring, can get up in plane without backfiring

ALBRIKB

went to purchase gas from station but as we filled it turns out got last 6 gallons in service station tank along with air..now when using boat it keeps backfiring and bogging.. at first you smell gas then you hear back firing, as you try to go and get up in plane backfires and doesn’t go fast,   Finally after letting up on throttle boat will go and run fine until you have to go slow for no wake zone then it happens again.  Changed fuel filters and added sea foam,  refilled with new good gas but problem has not gone away....any suggestions

randy56

You on the right path, you must have got all water in that last 6 gallons. Fuel treatment. Clean out filter again, they do not run to good on water.
I would take the fuel line loose at the carb. use a plastic cup, turn the key to engage the starter. Take's two people. Run a little gas in the cup and take a look at it. You may have to siphon the whole tank and start with fresh gas. 
You did not put in your personal profile, what boat you have.

ALBRIKB

2004 rinker 312 fiesta vee, 5.0 gxi e bravo engines.,  and thank you for that input on doing that. We did remove the gas line and check and honestly there was no water in the cup.   Any other suggestions.   We are waiting for a friend to bring us a tool to drain siphon and filter clean the gas.   We did refill the tank with new gas at a reputable station now.. 

GMSLITHO

you can also add some dry gas or  isopropyl alcohol to break up the water 

ALBRIKB

We added the dry gas, changed the fuel filter again and did see water and black particles in the gas.   Still back firing trying to get up on plane.    What next?

randy56

I had this happen once, drained tank, disposed of gas, I know how much it cost. ouch, Cleaned tank, started over. 
So i bought a 12 v fuel pump at an auto parts store and about 20 ft of fuel line. Got two 55 gal drums with lids and pumped it out. (leave drum's in truck) disposed of old gas at a environmental place. 

ALBRIKB

How did you clean tank...do you mean you just emptied fuel. I was seeing people say they had tanks emptied and polished.   Is it worth that to do.  We have about 40 gallons left in each tank.  

ALBRIKB

I also heard there is a tool that can be used to siphon and filter gas and put back into engine. Are you familiar with anything like that

Handymans342

That has to be done with professional equipment. There are companies that will come to your boat

randy56

Here is a company that will do it for you, //www.fuelandtanksolutions.com, Not sure if you have a company in your area like this one. In my small town there probably is not one.
so here is my DIY method, don't laugh, raise the front of the boat up so all gas goes to the rear, pump out all you can with 12 v fuel pump into drum. Remove gas gauge on top of tank, remove fill hose, use a flash lite in one hole and a rag on stick in the other hole, then switch back, flash lite in other hole, and rag on stick in the other, until clean. I used a cotton towel, cut into small strips, install new filter, and clean gas. 

Glassguy54

If you have the cool fuel modules, early versions were painted on the inside and were known to flake off and get in fuel system - black particles - bad for injectors!

Dream_Inn

Glassguy54 said:

If you have the cool fuel modules, early versions were painted on the inside and were known to flake off and get in fuel system - black particles - bad for injectors!

I've had this happen to me twice.  Went thru a total of 4 complete fuel modules & 2 sets of fuel injectors.  Didn't cause backfiring though, just bogged down because of lack of fuel.  The paint clogs the fuel regulators.

randy56

JOESONKO  I wonder if that is what is going on with his boat.