F20 running badly

Andrew Psencik · Mar 9, 2013

Just bought an f20 today. It was not running. I got it running by
adding fuel, cleaning the sediment bowl and carb. I did not
rebuild the carb, just a cleaning. This may be my problem. It
pops a lot and when the throttle is advanced quickly, it either
dies or pops very loud and sparks shoot out the exhaust (no
muffler). Any help would be appreciated. Thanks. A.P.

Bill Lisbon · Mar 9, 2013

Check your valves, you may have one sticking, this happens a lot to F-20's that sit for a while.

Elder Al · Mar 9, 2013

Pull your distributor cap and push against the rotor while you watch points gap. If Rotor shaft is worn badly causing this movement your points gap will be all over the place and it's time for a rebuild.

Oldiron29 · Mar 9, 2013

Andrew, If it had been running right before you got it, you may never know. Timming could make it pop. Bill is right a sticking valve, could be. Or starving for gas willmake it pop too.
Leave the timming for last. If carb is clean and getting gas than remove the valve cover and push down on the valve"s with a hammer handle see if they all move freely. Than check all your valve gaps. all it takes is one out of adjustment and it will pop. oldiron29

Andrew Psencik · Mar 9, 2013

Thanks for the replies. The guy I got it from said it ran like a top last week. But who really knows. The tractor is in great shape with a recent restore. Two questions though, which way of the lever is advance and which way is retard for starting. Also, how do you shut this gd thing off? Once I got it running, had to choke it to kill it. That can't be right. Please go easy, it's my first f20. Had many h and m tractors. This is a different breed for sure.

Super-H-Mike · Mar 9, 2013

Sounds lean to me, go into that carb some more, and be sure it gets plenty gas to the carb also.

Secret Squirrel · Mar 9, 2013

If it still has the original setup, original mag and all, the mag has a round cover on the rear of the mag, looking at it from the rear of the tractor. There is a hole in this cover that has a rod, connected to a longer rod that has a handle at the steering wheel post. Looking at the cover where the hole is, the cover rocks from 1:00 to 5:00 o"clock position. All the way up should kill the tractor, and keep it from starting. Move it down a bit until you feel a bump, and that is where you should start it. All the way down is maximum timing, or working position. You may have to run it at a different position for best preformance, depending on condition of mag, carb, etc. If you are hand cranking the tractor, the further down the mag is set, the greater chance of the crank kicking back.

F-Dean · Mar 9, 2013

Check the plug wires to make sure they are in the correct order. Especially if you bought it at an auction.

Tom Fleming · Mar 10, 2013

so, did you lube the valves before you ran it? Personally, if it hasn't run in awhile, I would use Marvel Mystery oil for the first 2-3 lubes of the valves, and I would overdo it a bit. you cannot over lube the valve train, but you do get to a point where you are just wasting oil. However, if the old girl has sat for awhile, like I said, overdo it. You might even want to take the valve cover off and shoot each valve with oil, and turn it over to watch that they are all moving full travel.

You should oil the valves for the first start every day that you run it.

The other suggestions are valid, but before you go down a whole bunch of different paths, make sure the valve train is loose, lubed, and working.

D beatty · Mar 10, 2013

I would first check vavles and spray them with a pentrating oil. Check cap and rotor( clean surface that brushs ride on) points and wires also clean cap on back of mag. I would open plug on bottom of carb. to see if your getting good flow to carb.Also dump some Seafoam in tank and run it.

F20 running badly

Andrew Psencik

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Bill Lisbon

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Elder Al

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Oldiron29

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Andrew Psencik

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Super-H-Mike

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Secret Squirrel

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F-Dean

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Tom Fleming

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D beatty

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