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perkel

2005 CRF 50 leaks gas from carb overflow

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I just purchased a used stock crf50 for my 6 year old. I had to go used because they are no longer selling 50's, the bike is in great shape, a little girl owned it before and she out grew, I have ridden it and all checked out, but when I stopped the gas kept pouring out of the bowl, the father told me the bike sat for the last 8 months, he got his little girl a 70 now. how easy is this to correct?

Thanks

AP

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Pull the carb and clean the needle and seat. When gas enters the carb, it raises the float which in turn pushes up on the needle. When the fuel level is correct, the needle will press up on the seat and stop any more fuel from entering the float bowl. If the seat and/or the needle is dirty, fuel will seep past, over flow the bowl and run out the overflow tube.

Give the rest of the carb a good cleaning too while you are in there, making sure you can clearly see through the jets. If you notice a "ring" worn into the end of the float valve, replace it.

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I had the same problem, and cleaning the carb made the fuel overflow/spill go away for a while. It ended up returning on several occasions and would go away after a carb cleaning. Got so bad that I cleaned the gas tank. Still, it happened again. I installed a clear fuel filter between the petcock and the carb, no more leak. I can see sediment sitting in the filter.

Is it just me or has anybody else gotten gas that had a lot of "crud" in it. I've installed fuel filters in my 125 and my quad because of it. Hopefully it's just a regional thing.

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I installed a clear fuel filter between the petcock and the carb, no more leak. I can see sediment sitting in the filter.

Can you explain this further? Or do you have any pictures of where you put the filter?

I am having this overflow problem, and need to get it figured out. Thanks.

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Can you explain this further? Or do you have any pictures of where you put the filter?

I am having this overflow problem, and need to get it figured out. Thanks.

it should be pretty easy to do. just go to the local auto parts store and pick up a clear fuel filter with the right sized in/outs and cut the fuel line from the petcock to the carb and then clamp the fuel hose on the onto the filter.

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It was pretty easy, just a little common sense and make sure the fuel line does not have hard bends or upward bends in it. I used new fuel lines (3/16" ID fuel hose and I bought a fuel filter for $2.73 from Advanced Auto Parts. The filter is a Purloator Premium Plus fuel filter, F21124). I got four really small hose clamps to make sure the hose doesn't leak. Very simple fix.

HOWEVER, if your float needle valve is shot, it won't work. I tested it by blowing into the fuel line going into the carb and manipulating the float to make sure air would enter when the float was down, and when I lifted the float, I couldn't blow air past the valve. It will work in the same concept if you removed the carb, drain the bowl, and blow air in while it is right side up. If you turn it upside down, air should not be allowed to enter.

Sorry for being so long winded.

I don't know how to post pictures, but I will put them on photobucket if enough people want to see them.

Tim

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It was pretty easy, just a little common sense and make sure the fuel line does not have hard bends or upward bends in it. I used new fuel lines (3/16" ID fuel hose and I bought a fuel filter for $2.73 from Advanced Auto Parts. The filter is a Purloator Premium Plus fuel filter, F21124). I got four really small hose clamps to make sure the hose doesn't leak. Very simple fix.

HOWEVER, if your float needle valve is shot, it won't work. I tested it by blowing into the fuel line going into the carb and manipulating the float to make sure air would enter when the float was down, and when I lifted the float, I couldn't blow air past the valve. It will work in the same concept if you removed the carb, drain the bowl, and blow air in while it is right side up. If you turn it upside down, air should not be allowed to enter.

Sorry for being so long winded.

I don't know how to post pictures, but I will put them on photobucket if enough people want to see them.

Tim

Yeah, I took a look at the line between the petcock and carb and see what you mean.

I also pulled the carb off, cleaned it thoroughly and put it back. Symptom still remains.

I am going to try the fuel filter and test the float valve needle tonight.

My neighbor seemed to think the float bowl was set too high and was simply allowing too much fuel into the carb in the first place. He said to just tweak it so it sits lower, thus allowing less fuel in. Anyone ever try this?

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Don't "tweak" it. It's plastic, and if you break it, they are not cheap to replace. If you think that the float is shot, when you take apart the carb again, get a glass and fill it with some gas. The fuel needs to be about 1" deep. Place the float in the gas to see if it will float. If it does, then that is not the problem.

Try blowing air into the carb through the fuel fill tube. The carb should let air in while the carb is upright. If it doesn't, the float is stuck. Turn carb upside down. Blow air in. If it lets air in, the float needle is either dirty or won't seal anymore.

Tim

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had the same problem with an old enduro i got the needle wasnt sitting right and witch causes it to come out the over flow i would pull the carb remove the jets and clean everything well with carb cleaner and reasemble it you shouldnt have any problems but then again i had to clean it 3 times

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Yeah, I took a look at the line between the petcock and carb and see what you mean.

I also pulled the carb off, cleaned it thoroughly and put it back. Symptom still remains.

I am going to try the fuel filter and test the float valve needle tonight.

My neighbor seemed to think the float bowl was set too high and was simply allowing too much fuel into the carb in the first place. He said to just tweak it so it sits lower, thus allowing less fuel in. Anyone ever try this?

When you have the carb apart, use a cotton swab dipped in carb cleaner and clean the opening where the valve sits [seat] any debree left will cause problems. Check the end of the float valve, it should be smooth and clean, if you notice a "ring" worn into it, then it will need to be replaced. Remember, there are only two things that will cause this problem:

1) Carb float incorrectly adjusted or leaking

2) Dirty or worn float valve and seat

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Don't "tweak" it. It's plastic, and if you break it, they are not cheap to replace. If you think that the float is shot, when you take apart the carb again, get a glass and fill it with some gas. The fuel needs to be about 1" deep. Place the float in the gas to see if it will float. If it does, then that is not the problem.

Try blowing air into the carb through the fuel fill tube. The carb should let air in while the carb is upright. If it doesn't, the float is stuck. Turn carb upside down. Blow air in. If it lets air in, the float needle is either dirty or won't seal anymore.

Tim

Another reason not to tweak the plastic part is that you will NOT be able to purchase a new one. Part of the lead ban on the little bikes includes selling the parts of the banned bikes. The only way to get a part is if it is an aftermarket part, or if the same part is used on another (bigger) model bike you can get it. A good friend of mine works at a local dealer and told me this. The factories will not sell the parts to the dealers so it's not the dealers fault the factories are just abiding by the laws.

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I worked on a friends CRF 50 for his daughter that had this same flooding carb problem.

Looking at the carb seat its finish looked like the carb's external cast finish being rough as well a white aluminum oxide

ring on the Viton carb needle vs bright and shiny smooth seat and clean needle.

This condition happens to many Honda engines used in lawn mowers, gas generators on and on due to the crappy aluminum alloy they use manufacturing their carbs.

This reported by a gas engine lawn mower repair shop I hang around all the time dealing with alcohol blended gas (crap) we have in California.

Repairing the carb vs replacement is quick and simple task as well way cheaper.

Take a piece of wood dowel and grind or sand it to a point matching the needle angle, add a touch of car polishing compound to the tip only, (fine not aggressive rubbing compound) and work it twisting into the carb seat a few times.

Do not overdo it just a few twists with light pressure.

Carb cleaner (Berryman B 12) then blast clean and check for a bright shiny seating ring.

A quick wipe of the needle with a rag dipped in lacquer thinner cleaning off the Viton rubber needle only if the needle

has no signs of ringing  wear or just replace it.

Your good to go until it acts up again due to the alcohol water attraction corrosion repeats itself again.

Winter storage of engines drained then run with 110 Union 76 leaded racing gas (no alcohol crap) has stopped winter stored engine carb problems on my equipment lasting several years that fire right up with the same stored gas.

CJ.....~~=o&o>..... 

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