Bad Carb rebuild????

[Cactus52]

Hey all:

Have a 85 Bayliner 2550 Ciera with a Volvo 260A engine and a 280 outdrive and a Rochester quadrajet carb. It is just out of a fresh tune up and just replaced the water separator. I had the carb rebuilt because it was full of some foul smelling stuff and not quite running right and because just having bought the boat wanted to make sure everything was ok.

I was running it last night at 3500 rpm and after about 10 minutes I started smelling gas fumes (I checked for leaks and found none) and about that time the rpm's took a dive and I was able to keep it right at 1400 rpm. It kept dying but I got it restarted a few times and trolled along until it quit and would not re-start. After 45 minutes when the tow arrived It started again but it was running rough so I shut it down. I would take it back to the guy who rebuilt it but he is out of town till wednesday.

I think for some reason it is running super rich. Or am I looking at something a little more dire???

Thanks
Cactus52

 

[Eric 3.7LX Alpha 1]

Re: Bad Carb rebuild????

Maybe,

Sounds like the needle valve might not be sealing on the seat.

There is a little bent wire that attaches the needle to the float bracket. The needle kinda hangs off that float bracket just over the seat.

When the carb needs more gas in it the float drops, lifts the needle off the seat and the pressure from the fuel pump refills the bowl until the float rises and drops the needle back on the seat tight, shutting off fuel supply to the carb.

It needs to be installed a certain way that holds the needle to the float, just over the seat. If it is not in the right spot, the needle will not contact the seat correctly and cause flooding. There are 2-holes in that float bracket that I've seen people route the bent wire thru, when in fact this is wrong and causes flooding. In the paperwork that comes with a rebuild kit, I remember reading to make sure it is not routed thru the hole or flooding will result.

 

[zbnutcase]

Re: Bad Carb rebuild????

Were the fuel filters replaced and the system flushed also?

 

[Alpheus]

Re: Bad Carb rebuild????

Check your fuel pressure. If its too high your engine will run rich and all the rebuilds and adjustments wont make a bit of difference...

 

[Cactus52]

Re: Bad Carb rebuild????

Well I think the fuel pressure is ok, it was running fine prior to the rebuild and the symptoms developed since then. I also replaced all filters and added a water separator and flushed the system. I think I might have it rebuilt by someone else.

Eric, thanks for the needle valve pic, is that right on top when I pull the air intake??

Thanks
Cactus52

 

[Alpheus]

Re: Bad Carb rebuild????

Rebuild it yourself...

http://forums.iboats.com/showthread.php?t=362542&highlight=rochester+rebuild

 

[Eric 3.7LX Alpha 1]

Re: Bad Carb rebuild????

Eric, thanks for the needle valve pic, is that right on top when I pull the air intake??

Thanks
Cactus52

no it's in the carb. check out that link and videos in it. Pretty much explains how to do it then decide if you wanna give it a go or have it done. Not that bad of a job to do.