QuestionThe snowthrower will only run with the throttle fully engaged. It will shut down if the throttle is disengaged. Model #HSSK50, SPEC-67394T, Unit model-624504X4B.
AnswerSAL
Carburetor problems produce different symptoms. There are many different types of carbs, but they all operate the same. The main types are the bowl and diaphragm. For info specific to your carb, we recommend that you purchase the proper repair manual for your engine. The manual contains exploded views of the carb, to help you get it back together properly the first time. They also contain diagrams of where the linkage goes, cleaning and adjustment procedures, and help you to spot worn parts. Most often a manual and a carb rebuild kit are cheaper than 1 trip to the shop. General problems and solutions are presented here, but due to the many variations of carbs out there, if you remove the carb, or disassemble it, be sure to write down how it is set-up now, to save fumbling later! No matter what type you have, a rebuild kit is inexpensive and will cure 90% of all carb problems. The first thing to do if the engine will run but acts funny is to try to simply adjust the carb slightly. Note the position of the screws now, in case you have to return them to the original positions. It is recommended only experienced do-it-youselfers attempt carb repair with out a manual.
Bowl-type carbs: Runs then dies: Check for stuck float, plugged fuel filter or fuel line. All tanks have a screen inside them to catch larger particles, and some also have a inline fuel filter. If everything checks ok, the passages inside the carb are plugged, follow the cleaning procedure outline in the manual to be sure you only have to do the job once! Surging, only runs on choke, sputtering: Is the air filter dirty? With the bowl as the lowest part of the fuel system, any dirt or water will wind up here. Turn off the fuel valve, or drain the gas tank, then place a rag under the bowl to catch the gas that will run out. Loosen the "nut" that holds the bowl on, and after the gas has stopped draining remove the nut and bowl, but do not let the float swing all the way down! Wipe out the bowl. The "nut" usually contains 1 or 2 very small passages, soak in (or spray with) carb cleaner and use a wire bread-tie or other soft wire to poke out the holes. Blow out with compressed air, if available. Put the bowl back on and try to start it. If it still will not start, it needs a good soaking and a rebuild kit. Drips, or crankcase fills with gas: Check the float first. Remove the carb, and then the bowl. Remove and shake the float, it should not be full of gas, if it is, replace it. If it is ok then the float needle/seat assembly should be replaced.
Diaphragm type carbs: They are less prone to trouble as a rule. Hard starting, or will not start: (spark is ok) The diaphragm may act as an auto choke or a fuel pump. It is made of rubber and will harden over time and no longer flex. It is the first thing to replace. Next check the fuel pick-up tubes for blockage, the check-balls in the pick-up tubes for free movement, and the tank for water. If it still is acting up, install a rebuild kit.
MISC. ENGINE PROBLEMS
