4.3 back fires, bogs down stalls

[ctak]

Took the boat out the first time idled away from the dock and gave here throttle and a loud back fire then pick up and ran OK for the rest of the day. Next time out same thing. Back fired when first going out and then ran fine. 3rd time as I was coming in the motor just died while running at 3500 rpms. Started back up and ran fine to the launch. Went out yesterday and ran out to fishing spot.. tried to idle down and she would die. Started up and give her a little gas and engine would bog and die. Let sit for quite a while and tried to start up and had to give her 2-3000 rpms to keep her running out of gear. Tried to put her in gear and she would die. After playing w/ her for 5 min finally got her in gear and ran back to the launch at 3500 rpms. about a mile from the launch she dies. Start her back up again and make it back to the launch. I suspect a fuel filter or something in the lines but the back fire has me confused. Will a clogged filter cause and engine to back fire when cold?

 

[Bondo]

Re: 4.3 back fires, bogs down stalls

Ayuh,... You have a Fuel Delivery Issue...
It could be as simple as clogged filters, or it's probably Crap in the Carb...

 

[ctak]

Re: 4.3 back fires, bogs down stalls

I pull the filter can and dumped the fuel into a class jar. It looks clean and clear. Just a little sediment. I'm wondering if there is a filter somewhere else.

 

[Alpheus]

Re: 4.3 back fires, bogs down stalls

Need some more info?

Year, or Serial Number...

 

[ctak]

Re: 4.3 back fires, bogs down stalls

This is on a 1994 Bayline 1850LS

Engine Ser. No. 0F076855 4.3 LX/V6 Alpha One.

 

[chaparall villain 2]

Re: 4.3 back fires, bogs down stalls

depending on what ignition it has it could also be thaat breaking down

 

[docoakley01]

Re: 4.3 back fires, bogs down stalls

Filter at the carb inlet good to check. Fuel quality overall, make sure the plug wires are in correct position are a few of the things I would suggest, particularly if you are new to the boat or plugs were recently changed.

 

[Alpheus]

Re: 4.3 back fires, bogs down stalls

Check the filter at the inlet side of your carb. After that check your fuel pressure. It will back fire if a sudden lean condition appears.

It sure does sound like a fuel delivery problem...

Start by reading these.

http://forums.iboats.com/showthread.php?t=283269

http://forums.iboats.com/showthread.php?t=295070

 

[ctak]

Re: 4.3 back fires, bogs down stalls

I took apart the fuel line from the pump to the carb. Didn't find a filter at the inlet to the carb or around the electric fuel pump. There was the brass nut for the flare aluminum gas line that goes into a larger brass fitting that screws into the carb took both off and didn't find a filter. So now I'm scratching my head. The distributor was replaced late last year and once it gets on step it runs fine. I'll keep looking.