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9020 19.5 onan cutting out, carb rebuild


9020dave

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Hey guys, My 19.5 onan is cold blooded which I don't mind. Once the eng warms up it runs really good. But then it wants to die out after about 20 minutes or so of driving. I can tell the fuel pump has been replaced at one time, there is what looks to been a bracket attatch to the fual pump that regulates fuel volume but noting is attatched to it (i.e. linkage from carb). There is a place on the carb where it looks like it may link together. Does this make sense to anyone? I cleaned up the carb the best I could with out going beyond the point of no return. After that the eng smoothed out alot. Also any suggestions for carb rebuild kits, where I may find someone selling kits on the web?
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There are several sponsors that could help you,Jacks Small engines ,Edens Ltd. very easy folks to do business with.
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Does it blow black smoke before it quits, no smoke but stutter for a while before it quits, or just die with no warning? I have a AC720 with the Onan CCKB and from excruciating experience here are a few things to try. We just fixed an ongoing problem with runing fine for twenty minutes and then quiting after blowing black smoke. Turned out the rubber on the tip of the needle had hardened and (with an electric fuel pump) was gradually seeping gas and flooding out. A new needle and reset the float solved the problem. If it stutters without smoke and then quits, replace the fuel filter before going further. It's amazing how long they can run with a partially clogged filter before they run out of gas. If it just dies with no warning, won't restart right away, but will start right up after sitting for ahwile, check the point box for oil. If the o ring around the pushrod for the points wears or the crankcase breather is clogged, oil will come up around the pushrod and flood the points. It drains out after it sits awhile so the tractor will start later. Hope some of this helps.
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You can get a feel for the fuel pump flow by pulling the return line off the tank, cranking over the engine, and watching for a reasonably stead flow of fuel. If very litle or non, bad fuel pump. I see a lot of debris from decaying fuel pump diaphrams stopping up the needle seat on the inlet of the carb. Another good reason for an electric fuel pump. Here's a link to my example of what I did for the fuel pump issue. http://simpletractors.com/club2/topic.asp?TOPIC_ID=31003 The carb is completely adjustable athough the main jet is under the carb and very hard to reach, but you should be able to adjust the cold naturedness out of it if there isn't anything wrong w/ the carb. or the fuel flow. Most of the problems I see w/ these engines are associated w/ worn ignition poblems or simply faulty components. Some major examples are burnt points, bad condensers, worn points boxs and plungers knocking the engine into a low timeing mode. Condensers are notorious for collecting moister and shorting out killing the ign. Best thing you can do is try to determine what your loseing when it does cut out. Do you loose ign? Do you loose Gas supply? Try to narrow it down before you blindly start changeing stuff so your shure when you find the trouble. Good luck. Let us know how you come out.
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You may find that the bracket(i would call it a lever) on your fuel pump is a primer. Move it back and forth with the engine off and it will pump fuel to fill the carburetor. I have a few BF and CCK fuel pumps that are like that.
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