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MarkH

need help w \big ten

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MarkH
My uncle gave me a big ten that sat around for awhile. It had a very bad miss and would leak gas out the bottom of the air horn when you would crank it over.I rebuilt the carb and checked and made sure it is not warped.It still leaked out the bottom when you would turn it over, but not while just sitting there. It also had the miss yet. I pulled the head and found a small leak of the head gasket so I replaced it and the intake valve that had been worn badly. I lapped the valves set the clearance and put it back together. Now it starts, runs for a second or two and then quits. After you turn it over a little it starts to run gas out the bottom of the carb yet, however it does not leak if just sitting there. I took the carb off the head and it is soaked in the intake port, but the spark plug is dry. I'm out of ideas. Could my valves be out of time, or is there something else I may be overlooking? Any help would be greatly appreciated.

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dlcentral
flywheel key could be partially sheared,,best to take motor out put on a bench to check keyway,, get running and rebuild leaky carb.,, imo,,

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Woodydel
Did you replace the emulsion tube? It comes with most kits. I think that is the source of your gas leaking into the carb...Woody

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HubbardRA
I had a B/S 10 Hp that had a small insert made into the bottom something like a candle wick. It would let the gas drip out if you flooded the tractor. You may have the carb a little too rich. My current 10 Hp tractor can only be choked till it pops the first time then the choke must be opened or it will flood. This is because the easy spin bump is no longer on the cam lobe. Also check the play between the throttle shaft and carb housing. I have had intermmitent missing problems with carbs that had worn throttle shafts and and also the hole in the carb. Just fixed a Kohler with this problem. I put a bushing in the carb and installed a new throttle shaft. This stopped the missing. The wear is usually due to incorrect carb adjustment which causes the constantly speed up and slow down. Rod H.

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Dutch
I'm not sure what you are calling the emulsion tube. would that be the nozzle that goes up through the float bowl and float? I replaced the float, float needle valve, nozzle, gasket and throttle valve. I also checked to make sure it wasn't warped. The throttle shaft seems pretty tight.Compresion seems pretty good but it acts like it isn't getting enough gas into the combustion chamber. The spark plug is dry, it isn't fouled but the intake port is soaked when you take the carb off. It is like it is pulling it into the manifold and intake but not the motor. Is there any way to check the nozzle seat to tell if it is leaking? Would that cause it to do this. The only thing I can think of I didn't replace is the high speed needle valve and the idle needle valve. It will start with no choke but only with throttle at idle and only for a few seconds.

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Woodydel
The emulsion tube crosses through the carburetor throat diagonally in an upward direction. It is made of brass. If there is blockage at the top end (next to the low speed idle screw gas has nowhere to go except into the carb throat and then out the bottom of the carburetor. If the float were stuck gas would flow out without the engine running. Raw liquid gas doesn't burn. Only the vapor will burn..Woody

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Skywriter
Did you check the point box? There is a rubber seal on the plunger that can act like a pump and pump oil into the point box. Clean the box and remove the rubber seal or replace it.

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