51 B One minute running fine.... the next minute..

At high throttle plate angles [wide open] the economizer system does drop off & doesn’t pull the float bowl to negative pressure but by then the air intake restriction of the intake pipe & air cleaner is enough to lower the carb’s lower float bowl area to below atmospheric pressure & again the fuel level in that clear hose will drop below fuel level..

If a 3/8” hole were drilled in the top of the float bowl above fuel level that clear hose would then read the fuel level correctly at all throttle settings. Also if the float bowl gasket was missing or leaking enough it would allow the level in that clear hose to show the correct float bowl level..

Give it a try when you get a chance & let us know what you show..

Your clear hose suggestion is still one of the better ways to measure the fuel level in the carb float bowl it just isn’t very accurate on a running engine..

JDClooney@aol.com

~The first is: that you might have a late model NON vented gas cap on your tractor, that B of yours needs a vented gas cap.. [does the problem occur faster & more often with a full fuel tank? If so suspect a tank venting problem]

~The second is: that you have a leaf other partially floating piece of junk in the fuel tank that occasionally gets sucked into the fuel pick up fitting [run that fuel flow test again, only this time run the fuel into a pail & keep pouring it back into the tank,, run the fuel flow test for about 1/2 to 1 hour as that will simulate your plowing sequence]..

~Third thing is: make darn sure your metal fuel line from the tank to the carb isn't touching or too close to the exhaust manifold.. [if that fuel line is too close to the exhaust manifold you could be getting vapor lock]..

~Forth thing is: if your tractor has been retrofitted with an oil pressure controlled fuel shut-off make sure it has a good smooth operation & has good oil pressure to it..

~OK here’s what you are fighting… Seeing as your problem is intermittent you won’t find it easily.. If it’s a fuel flow problem [probably is] you will have to duplicate the problem scenario to find it with a test.. That means to do a fuel flow test you will need to do it many times , probably with the front end facing up hill, & do it for long periods..

Any questions just post back or E-Mail & we’ll try to help you find your problem..

JDClooney@aol.com

First, make sure the gas cap is venting so shes not air locking. I had a tractor starve for fuel once and the cap was sealed tight was the reason. You might also check the carbs baffle isnt clogged up so air can enter.

1) With the gas on at the sediment bowl or any shut offs, open the carbs lower drain cock/plug and let it flow a minute or 2 to be safe and see if that 1/16 inch stream flows continuous????

2) If not, remove the gas line from the carb and see if a good strong steady stream the size of the lines inside diameter flows continuous.

3) If not, remove the glass sediment bowl and see how well gas enters the top to fill the bowl area. If shes not strong n steady there, dirt or rust etc may be inside the tank or inlet pipe area and she needs cleaned n purged.

4) If she flows well out the line to the carb but not out the bottom per test 1 above long enough, I would first remove the carb inlet strainers side drain and see if you can clean out any rust or crud..... ..... . If that dont help, I would remove the side inlet strainers top nut n cap(may need new gasket) and clean that all out..... .... If that dont help, I would remove the carbs lower bowl and clean and check the needle n seat area and the float level. Dont loose the lil spring in the bottom.

OTHER THINGS TO LOOK AT:

Have you adjusted the top load needle settings lately?????

Have you removed te air cleaners lower bowl to make sure its clean and NOT have any water???

DOES CHOKING SOME get her back up n running????? ????? If so, there may be some other internal carb restrictions, let us know if you need any carb cleanign tips!!!!! !!!

There could be some ignition problem, but it sounds more like fuel starvation for now, so I wont talk spark unless we need it later. I think maybe the float could be low, or a needle n seat restriction, or a tank outlet area or sediemnt bowl restriction, or a clogged cap or baffle, or something like dirt or metal (baffle broken) in the tank restrictign fuel flow for now.

Post back your findings or any questions or e mail me at jmn50@msn.com.

Let us know, Good Luck n God Bless ya Brad.

John T