I have an old, standard, cheap-o, four stroke push mower. I don't know what kind of engine it has, but it's probably similar to a typical Briggs & Stratton. I bought it used several years ago from a friend for twenty bucks. The carb says "Tecumseh" on the float bowl.
When I start it up, I prime it a handful of times. If it's cold out, I may have to repeat this a couple times before it will run on its own. If it's warm out, the initial prime may keep it going. It will usually run a little rough/weak until it has warmed up for a minute, or so.
The other day, I was almost done mowing the lawn when it sputtered for maybe thirty seconds, then quit. I thought it might be out of gas, so I filled it up. I never could get it restarted. If I prime it, it will run for a second off the prime, but then will die.
A friend suggested that it might have a safety mechanism where it won't run if the oil is low. Well, the oil was low, so I filled it up, but that didn't fix it. I know it's getting a spark, as it will run off the prime. However, I got a new plug and fresh air filter, just for good measure. There is plenty of gas flow out of the hose. I took the bowl off and the float seems to control the flow of fuel into the carb correctly. If left alone, fuel flows out. If I raise the float, the fuel flow stops.
I took the carb apart to try to clean it out some. I put a brush, followed by carb cleaner, through the tube coming straight up from the float bowl, and through the brass tube which runs from the entrance to the throat down into the carb at a forty-five degree angle. Those seem clear. The orifice in the bolt that holds the float bowl on appears clear, but it's too small for me to know for sure. I'm not sure what else there is to clean.
It looks like the only control on the carb is a butterfly valve held by a spring. I think this must act as a governor. The spring holds it wide open. It appears to close partially after firing up. I guess the suction pulls it toward the closed position if the engine runs too fast. This valve moves freely, but has firm spring tension on it.
After all that, there is no difference. If I prime it or shoot some starter fluid into the carb, it will run for a second or two off of that fuel, then die, as before.
It seems like a fuel starvation issue, but this carb seems so simple, I don't know what else to try. Here are some photos of the carb.
Any suggestions?
Thanks,
Jay
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
When I start it up, I prime it a handful of times. If it's cold out, I may have to repeat this a couple times before it will run on its own. If it's warm out, the initial prime may keep it going. It will usually run a little rough/weak until it has warmed up for a minute, or so.
The other day, I was almost done mowing the lawn when it sputtered for maybe thirty seconds, then quit. I thought it might be out of gas, so I filled it up. I never could get it restarted. If I prime it, it will run for a second off the prime, but then will die.
A friend suggested that it might have a safety mechanism where it won't run if the oil is low. Well, the oil was low, so I filled it up, but that didn't fix it. I know it's getting a spark, as it will run off the prime. However, I got a new plug and fresh air filter, just for good measure. There is plenty of gas flow out of the hose. I took the bowl off and the float seems to control the flow of fuel into the carb correctly. If left alone, fuel flows out. If I raise the float, the fuel flow stops.
I took the carb apart to try to clean it out some. I put a brush, followed by carb cleaner, through the tube coming straight up from the float bowl, and through the brass tube which runs from the entrance to the throat down into the carb at a forty-five degree angle. Those seem clear. The orifice in the bolt that holds the float bowl on appears clear, but it's too small for me to know for sure. I'm not sure what else there is to clean.
It looks like the only control on the carb is a butterfly valve held by a spring. I think this must act as a governor. The spring holds it wide open. It appears to close partially after firing up. I guess the suction pulls it toward the closed position if the engine runs too fast. This valve moves freely, but has firm spring tension on it.
After all that, there is no difference. If I prime it or shoot some starter fluid into the carb, it will run for a second or two off of that fuel, then die, as before.
It seems like a fuel starvation issue, but this carb seems so simple, I don't know what else to try. Here are some photos of the carb.
Any suggestions?
Thanks,
Jay
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
