9N only runs with valve open 1/4 turn

hoopop

New User
1941 9N runs fine when fuel valve open about 1/8-1/4 turn. If I open further or to the normal 2 full turns
open it begins to sputter and stall and die if I don't turn it back to just 1/8 or so open. We took the sed
bowl off and cleaned good and the screen etc and put it back on the other day and it worked fine for that
day. Then next time same problem runs only if 1/8 and no more open?? Any one have any idea what my problem
is.
 
Sounds to me the float is stuck or has a hole in it in the carb. You are having to regulate the fuel with your valve instead of the float in the carb doing what it is supposed to do . Just a thought.
 
Did you do PM on the carb? Engine cold, place a pan or coffee can underneath to catch the fuel, and remove the carb drain plug on the bottom. Open the Sediment Bulb Valve 2-Full Turns. Observe that the fuel flows out of the drain steadily. Shut off valve and disconnect the fuel line at the carb inlet brass elbow and point line into the container. Open valve 2-Full Turns and observe if fuel flow is a good, almost pencil thick steady stream uninterrupted. If there is any hesitation, the obstruction is in the sediment bulb assembly, most likely a lot of floating sediment, rust particles, and dirt in the gas tank that impedes the fuel flow. The Fuel Valve has a rubber seal in it that gets all chewed up and pieces of it can also get in the inlet orifices and plug up. A new fuel stem valve is about $6 and you don't need to buy a whole new Sediment Bulb Assembly. It is the only part that will wear in the assembly. While fuel line is off carb inlet, remove the brass elbow and clean the third in-line screen on the end of it. This screen is often overlooked when doing carb/fuel issue troubleshooting.


Sediment Bulb Fuel Valve, p/n APN9194:
SC9Vznll.jpg

Tim Daley(MI)
 
Thanks gman, carb was rebuilt while back, float should be ok but will check condition and operation. Thanks
 
Thanks Tim, checked the flow the other day. But not since it happened again. Will do so and make sure it is steady and uninterrupted, not erratic, etc. You rec re the fuel stem valve condition might just be the trouble....I don't think it has ever been replaced and I have had the tractor for almost 40 years with no problems of this kind. Carb overhauled at least couple times...but not the sed bowl. So, will order up this part and change it out. thanks much for the advice. Will post and let you know the result.
 
Here is a photo of worn ?seals? from fuel sediment bulb valves. They are just rubber and I have seen some on the cheaper Cheena made parts that are actually vinyl which tear more easily and get eaten by gasoline. The valve stem is the only working part on the assembly. Unless the internal screen is missing or somehow the fuel line inlet and outlet ports have boogered up threads, there?s no need to buy a whole new assembly. These threads are special size -7/16-24? for ?? brake and fuel lines, and I?ve worked on guy?s tractors whom they tried to ?fix? their stripped threads themselves by chasing with the wrong size tap (7/16-20) thus creating more of a leak there. The next thing is they try to apply yet another band-aid with Teflon tape ?wrong! Basic PM of the sediment bulb ?empty the glass bowl every now and then. The OEM Operator?s Manual says every 60 hours of operation to drain carb and fuel line too. Replace the horizontal fine mesh brass screen or at least clean it good in solvent and blow off with compressed air. Replace the top bowl gasket with a good thick cork style ?the rubber ones tend to fail early, at least from my observations. If the float is sticking, you can remove the air cleaner rubber hose at the carb intake and there will be gas in the throat there. Also, in my first picture I show the new stem with a new handle and 8-32 screw and a bottle of LOCTITE Threadlocking compound. I learned a long time ago to put a dab of this on the new screw when installing the new handle to keep it from loosening up and thus the handle falling off in the field. You usually don?t know it fell off until you get back to the barn at the end of the day. There is never going to be a need to ever remove the handle so installing it now permanently will ensure it won?t come off. Then, when it?s time to replace the stem again, you?ll get a new handle and screw in the kit. The fuel system is not to be taken lightly. You don?t want ANY fuel leaks whatsoever ?that is a recipe for disaster. Do the job right the first time.

Worn Sediment Bulb Valve Stem Seals:
QoHg4qfl.jpg
 

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