B running rough--fuel filter cavitation

The in line filter didn't come from AC with the tractor. Its likely a plastic filter made for automotive service where there is a fuel pump to supply enough pressure to push througho the fine screen. Your tractor will run better if you replace it with a piece of tubing or the filter for a gravity fed engine, like one for a Briggs engine that will flow more freely. Also check the tank for floating stuff blocking the sediment bowl inlet screen inside the tank.

Ignition has nothing to do with fuel starvation. There are many testimonials about how good the electronic ignitions start, and a few about how expensive they were when the failed. There are 4 parts in the standard system, and at least ten times as many in the electronics which makes the odds of failure higher for the electronic system. And for the price of one electronic system I can buy more than sets of points and condenser and on my tractors I've only had to change them once in ten or 20 years. It is important to keep a bit of cam grease on the cam and a tiniest bit of oil on the point's pivot, and more oil in the felt under the distributor rotor to lubricate the centrifugal advance parts.

Gerald J.

It sounds to me like your vented gas cap might not be venting. I would put a new screen in the sediment bowl and throw away the add on filter and replace steel tubing from sediment bowl to carb. Sediment bowls worked fine for the last 50 years. Make sure the tank is clean and the gas cap vent works. If you have rust in the tank a temporary fix is to add a short stand pipe to the top of the sediment bowl base but if it continues, the fix would be to clean and line the tank with Red Kote or some such tank liner.

Edited by CTuckerNWIL - 09 Jul 2010 at 1:07pm

High octane gas won't help a low compression engine for anything. It may hurt by needing a different mixture to burn well. High octane reduces the tendency of lean mixtures to ping in high compression engines.

The filter is definitely a problem and not needed. Junk in the tank is a strong possibility.

Gerald J.

Did this tractor sit for a while before you got it ? I remember when we got our Farmall Cub Lo-Boy it had sat for 8 or 9 years with gas in it no matter how good I flushed the tank and cleaned the carb it kept plugging up with gunk,lasted almost the first whole season Heat from working,strong new gas and vibration kept loosening up stuff from all the nooks and crannies in the fuel system. By the end of the summer I could tear down that carb wash it out and be back mowing in about 20 minutes I put Stabil in every can of gas I buy and havent had any problems with it in years. Check that the cap still vents and I would put a Briggs filter on it in place of the other one to catch any junk coming out of the tank before it gets to the carb at least for a while like the other post said. T.J.

realolman wrote: I don't know anything about a B... maybe it doesn't even have a fuel pump... I don't know , but one time I had a fuel pump that formed a ring of varnish around a valve and then the ring came loose and stuck under the valve....looked like a little hemlock needle.... thing drove me nuts till I found it.  The fuel filter would be empty, so I thought sure the tank/ line was plugged.... but it never was.  Took it off and cleaned it... put on a new fuel line.... the fuel pump / varnish pine needle  would apparently push the fuel back up into the tank.... but it would run fine for an hour or so, and when I let it sit,  the fuel would fill everything back up by gravity.    Having said that... it doesn't explain anything about your fuel filter sucking shut... that seems to indicate a plugged fuel line / tank.... and a very good fuel pump.   Guy tells me that the gas used these days is hard on fuel lines... maybe the line is collapsing somewhere.