Need help with 250 dying

[indymachinist]

Guts I just got my 250 up and running. It will start right up and run smooth and Rev responsively. But then suddenly while idling it will fall on its face and almost die. At that point if you give it any gas it will not rev and will die. Any thoughts?

[indymachinist]

I'm away from home and in a horrible cell signal area. I will post a video when I get home. It's just odd it runs so smooth for minutes at a time at idle but then will suddenly fall on its face and sputter as if it runs out if gas. Then it will catch itself and smooth right back out.

[2002yanks]

I am going to assume it still has the stock 1 barrel. Check the filter that's right behind the fuel inlet on the carb(filter looks like a thimble). It is usually plugged with small particles. carry a can of carb cleaner to clean it out, or you can run a filter before the fuel pump and one before the carb and leave this one out.

[cooperhw]

When it does the dying part, try taking off the gas cap. Kinda sounds like it might need a vented cap and not have one. It would starve it for fuel and be trying to suck through a plugged straw.

[indymachinist]

Originally Posted by 2002yanks

I am going to assume it still has the stock 1 barrel. Check the filter that's right behind the fuel inlet on the carb(filter looks like a thimble). It is usually plugged with small particles. carry a can of carb cleaner to clean it out, or you can run a filter before the fuel pump and one before the carb and leave this one out.

Yeah it still has the monojet carb in it. The carb has been freshly rebuilt and the little filter behind the inlet is clean.

Originally Posted by cooperhw

When it does the dying part, try taking off the gas cap. Kinda sounds like it might need a vented cap and not have one. It would starve it for fuel and be trying to suck through a plugged straw.

That is a good idea. I should have tried that. The gas cap is one of those locking ones so maybe it isn't vented.



Here is a video of it running. Its muffler was blown wide open by the previous owner so it is pretty loud. Also the idle is set super high in an attempt to keep it running.

https://youtu.be/gwqa028QXuc

In the video it is running by itself. There is no one in the cab giving it gas or anything.




The falling on its face thing did seem to settle down and I was able to drive it around some. While diving it seemed to run pretty good. Maybe it just needed to run some? Gummed up fuel hardline or something? The previous owner had put new rubber fuel lines and a new fuel pump and filter on it. I put in 5 gallons of fresh gas and some stabil when I put the rebuilt carb back on it.

[bill3rail]

Who rebuilt the carb? Was the float set properly?

[indymachinist]

I rebuilt the carb and set the float according to the instructions that came with the kit.


In other news, the wife had set up a photographer to come up to the family farm on Saturday and do some fun pictures with us and the truck. I should have seen it coming a mile away but the truck decided it didn't want to run so I left it on the trailer in the barn and walked away.

I'm a new school guy so that old carbed 250 cam kiss my butt. I had planned to drive it around a bit this fall till the weather got nasty but now it will sit in the barn and wait for me to yank that silly old boat anchor out. I can't wait to get a fuel injected engine in there.

[GRX]

Did the carb have a Nitrophyl float? (plastic) If so replace it with a brass one. Common mistake is pushing the float too hard when measuring. Just enough to ... oh, wait. You have already given up. I'd rather rebuild a simple Monojet carburetor than a set of injectors. But that is just me. You bought a 47 year old truck because you wanted old school. Either get used to working on it, or pay someone else to do it.

[firedemon]

where did you get the carb kit I cant even find a listing I can find the whole carb but no rebuild kit

[EARNHARDT#3]

Originally Posted by firedemon

where did you get the carb kit I cant even find a listing I can find the whole carb but no rebuild kit

They're readily available. eBay, rockauto.com , advance auto parts, auto zone, Napa, carquest, they all sell them. If it's for the '67 in your profile picture it would originally have a Rochester model B. It could've been changed to a monojet, carter or something else though over the years.

[indymachinist]

I got the carb parts from here:

http://www.carburetor-parts.com/Roch...it_p_2395.html

The kit shipped fast, was nice quality, included instructions and a set up sheet, and the company has videos to help with rebuilds on youtube.

Above is the kit I got for my Monojet. It included the brass float, and I was very careful setting the float level so I did not push on the needle and seat.


I guess I haven't 100% given up on it. Only about 90% or so. It is just frustrating to me because I have no idea what the hell is wrong with it.

[88Ironduke]

Feeling your pain. It sounds like a fuel starvation issue. Test the theory by running a small source of gas to the fuel pump and tank the tank/lines out of the equation. The sending pick up line is primed to pick up some nasty gungy stuff from the tank. Mine was actually plugged solid up to the top of the tank. Mare sure you are getting a good fuel supply to the pump.

Paul

[indymachinist]

Yeah running of a little gas can will be the next thing I try. Gonna drag it out of the barn this evening.

[firedemon]

Originally Posted by indymachinist

I got the carb parts from here:

http://www.carburetor-parts.com/Roch...it_p_2395.html

The kit shipped fast, was nice quality, included instructions and a set up sheet, and the company has videos to help with rebuilds on youtube.

Above is the kit I got for my Monojet. It included the brass float, and I was very careful setting the float level so I did not push on the needle and seat.


I guess I haven't 100% given up on it. Only about 90% or so. It is just frustrating to me because I have no idea what the hell is wrong with it.

thanks just what I was looking for

[indymachinist]

Well it is home with me now so I will play around with it a hit more before I give up on it

[indymachinist]

Spark plugs are black. It's not super crusty black but a light coat of black soot on the electrodes and porcelain also.

So I am assuming too rich? What do I do about that? I didn't change the main jet as I only had the one that came with the carb and the rebuild instructions say the jet should not need messed with.

This is a previous reman carb though so maybe it was wrong to begin with.