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I was on my way to work yesterday and the truck decided to quit. I tried to start it but stopped trying when I saw white smoke coming from under the hood. I popped the hood to see gas all over the carb. When BCAA arrived he watched it and said gas was flowing out any holes. My father believes the float may be stuck, the repair shop guy thinks there must be a piece of something that got in one of the jets. I'm just looking for any other possibilities. I'm lucky it didn't ignite on the hot exhaust.

That condition is usually caused by a float sticking OR a piece of crud (technical term there) keeping the needle valve from seating. Both conditions keep the needle valve from closing & shutting off the gas when the bowl is full. The fuel pump keeps pumping & gas goes everywhere.

Been there. Done that.

Tiny's right. Needle valve or the float. if it's the float, you can rap on the bowl of the carb with the handle of a big screwdriver to unstick the thing, but if it's the needle valve... You'll have to pull the top off of the bowl and clean out the crud.

Mine stopped doing that when I installed a fuel filter.

OldBlue58,

If your float sprung a leak, it would sink. The above scenarios are more likely, but be sure to do a "sink or swim" test with the float.

Stuart

The "crud" thing is most likely the problem. That's why I use a fuel filter from a fuel injection era vehicle. It will stop the smallest particle from getting to the carb. The best one I've found are for Nissan cars and trucks. They still use the hose connection instead of a fitting, making it easy to mount to an old truck,
Scott

My float stuck once after I parked and having a full tank of gas cause a siphon effect and it filled number 1 cylinder with raw fuel.When I went to start it after work it was like it was seized.I pulled all the plugs and turned it over and shot gas all over the place.put the plugs back in and hosed down the fuel spill and she fired up and got me home .I then pulled my fuel line off and gave the carb a shot of wd40 into the fuel inlet and have not had a problem scince..
James

If it,s a piece of crud in the needle & seat you usually can clear it out with this methed. Put a vice grip on the flex hose by the fuel pump to block off fuel flow. Start the engine & run it til it dies or almost dies. Remove the vice grip & restart the engine. If once doesn,t do it try it again. When the carb gets out of fuel the foat drops way down opening up the needle valve all the way. When the fuel comes rushing in it flushes the particle past the needle & seat. If 2 times doesn,t work it,s time to dissasemble the carb. This has worked many times for me, saving tearing down the carb. Sometimes this happens right after changing fuel filters.

Thanks everyone for the guidance and comments. It makes sense to me :-) I have a fuel filter on the gas line which was changed about a year ago so I'd be surprised if it was the crud but then I filled the tank over 1/2 full for the first time in a long time. Thanks for the method of clearing the needle valve.

Every time I've had an issue with a Rochester B it was something to do with the float. I've found that even the old brass ones are full of pinholes. The B has a split float and if the two chambers don't have exactly the same bouyancy it causes friction on the pivot point and tends to cause trouble with the fuel level in the bowl. I replaced the float with a new one a few years ago and chamfered the needle valve seat with a ball bearing and I haven't had a single leak or problem since.

Well, I finally got the truck back from the shop today and it was the float. It had sunk with small holes and has probably been the reason I've had problems with the carb for a while. The replacement float turned out to have pinholes in it too. Finally got a replacement that works. Thanks for the advice/comments. Cost me $235 which happens to be the same as the size of engine.

I've been driving my parents diesel jetta for a week. I missed the trucks various rattles, buzzing radio when an electric bus drives buy and looking down at the other cars. Glad to have Mabelline back!

Are there any other tricks to removing debris from the needle valve without taking the carb apart? I think I have some crud in mine (it is gushing too) but I seem to have metal fuel lines all the way to the tank so I can't pinch off the fuel supply to the fuel pump. I'm also pretty sure it isn't the float because I just rebuilt this thing (Rochester B) not too long ago. Thanks in advance.

Mine was gushing about a month back, and I got very good at popping the top off the carb in short time. There are only four screws and a gas line holding it in place. You won't remove the whole carb, just the upper body including the needle valve and float. In my case, the problem was the alignment of the float, causing it to bind in the float chamber.

Karl

[quote=gjberche]Are there any other tricks to removing debris from the needle valve without taking the carb apart?

Disconnect any line & cap it off. Then run the engine till it uses up the gas in the carb. Hook the line back up & restart it.

Just to follow up, I did what Wrenchbender said on my truck and the gushing stopped. I disconnected the fuel line near the fuel filter and ran it into an empty gas can. I'm assuming whatever debris was in there is now floating around in the bowl... anyway, thanks for the tip! I'll file that one away for future use.

Save yourself a lot of trouble and cost...ditch the Rochester...do a search of this site...literally hundreds of Rochester problems just like or similar to yours...the carburetor is junk. (P.S. after struggling for several years with a problem like yours I found that reducing fuel pressure with a inline adjustable pressure gauge to 4.0-4.5 lbs solved the loading-up problem.)