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sjmorgan

B-112 Carb/Float Problem?

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sjmorgan
Have a B112 with the old B/S cast iron engine. For years has run fine until a month ago. It would run for about a half-hour, start acting like it was running rich or starving for fuel, then die. It would not restart until an hour of "sitting." Then run fine for a half-hour with the problem starting all over. Decided to put in a carb kit this weekend. Started fine. Made the adjustments. The tractor never ran so well, until one hour into mowing. Started acting rich, then died with fuel pouring out of carb. Can't get the tractor to run since. I have had the carb off one million billion times looking, cleaning, trying "things" and just to personally curse it. Open to suggestions.

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HubbardRA
Sounds like the float may be taking on fluid slowly. I had that problem with son's 64 Landlord. Replaced the float and everything worked fine. I had the carb apart several times before I noticed the liquid in the float.

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3314WV
Check the float for some fluid. Otherwise check needle valve for either dirt on the seat or scoring. As for the fire, it sounds like coil breaking down when hot....spark will look fine when starting cold, but will weaken when hot and start yellowing out.....

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chip61
Mine does the same thing. May run 20 minutes, may run 2 hours, just don't knnow. I run my gas cap loose, doesn't seem to help. When it dies, I take the cap off and put a small amount of air pressure on the tank. Then we're good to go again. I think maybe my needle valve sticks closed and the air pressure forces it open??

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MrSteele
Chip, your problem sounds more like a dirty screen in the tank, or clogged filter. Next time it dies, pull the fuel line off and blow back through it until you hear gas bubbling in the tank, then start again. If it runs as it should, try removing the screen filter in the tank, that is located above the shutoff fitting. You'll have to remove the gas, then remove the shutoff. You can either simply remove the screen, or change the fitting and add a shutoff somewhere inline. Don't forget to also add an inline shutoff if you remove the one at the tank. The first problem sounds like it has 2 answers. A waterlogged float will make the carb run over, and a bad coil loses fire when it gets hot, but will run fine cold. When you leave it sitting around for a few minutes, the coil cools off enough to work again, but will overheat, cause the engine to act like a fuel problem, then die. Check your spark when it dies. If it is weak, or yellow, and less than 1/8" it may not run the engine. A good spark is well over 1/8" and blue in color.

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sjmorgan
Finally landed back on earth to enter an update on my problem. What I found was a very loose locking nut for the point adjusting screw. The gap was down to .011. Readjusted to .018 and double checked that the locking nut was tight. That in itself seems to have solved the engine quitting after running for a 1/2 hour. I have run the tractor now for over three hours of mowing without a hitch. I still have gas leaking out of the carb after I shut the engine off, though. The carb did not leak before the installation of the carb kit. Float is not taking on fluid. I've put in the old float valve. Looked at the valve and valve seat with a mag glass. Everything looks clean and unscored. I just can't find what the cause is.

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HubbardRA
A leaking carb after shutting down the engine is a common problem with B/S carbs. I put a shutoff valve in the fuel line on all my B/S engines. I usually shut the valve off just before shutting down the engine. That way there is never enough fuel in the bowl to cause the leak. That is much easier than chasing a leak that is nearly impossible to stop in some cases some cases. The leaks never seem to effect the engine while it is running, only when the engine is shut off. One of my tractors will only leak when it takes a notion to. It went for 5 years after I put the engine in it before starting to leak. There have been several times recently that I forgot to shut the valve off and the carb didn't leak. If they had the electric shutoff valves like the new ones do, nobody would even notice these small leaks.

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