I have just ordered a new OEM Briggs carb kit to be installed in a few days once it arrives. In the meantime, I do appreciate the many good suggestions for what is going on with this old B&S 16 hp L head cast iron engine, horizontal shaft. It’s true monster of an engine, but has tons of torque when running properly. To all who suggest replacing the condenser, it was the first thing I did before anything else. So, for now I’m ruling that out, unless every other suggestion proves fruitless as well. Then will try a second new condenser.
As for the fuel filter, as mentioned above, I have replaced it with what is recommended in the parts manual, using a metal filter about 1.5“ X 2.5” not counting the inlet & outlet tubes. It has an arrow showing the correct direction of flow. Gasoline flows readily through it. As for the little screens mentioned…I haven’t found any other than the two elbow fittings at the bottom of the tank. I couldn’t see inside the tank to tell whether or not they have screens on them, but maybe. Whether they do or not, gasoline flows freely from the elbows when the hoses are pulled.
If you haven’t seen the carb on these engines, it is a two piece carb, with the intake air entering at the top, but then diverted 90 degrees into the carburetor. This carb also has a Welch plug at the rear of it, about the size of a frost plug on a liquid cooled engine. The high speed needle/jet faces downward at an angle of about 50 degrees. The low speed needle/jet sits horizontally at the top of the carb. The float needle is independent of both, and is only accessible by disassembling the carb. So, here’s a strange observation. Normally, the float needle seats in a removable brass fitting. On this carb, none was present. Huh? Well, it wasn’t in there and the engine had been running fine, so this remains somewhat of a puzzle. How can a steel needle seat into pot metal? I will be putting on my magnifier hood this time around, to inspect that mystery more closely. With the kit not yet here, I don’t know if I will discover a brass seat included or not. If I do, then someone has been in there before and didn’t put it back in. But, if that were true, how would the engine run fine for many years without any issues. Also, how could a needle seat perfectly in molded pot metal without allowing the fuel bowl to overfill and leak? Soaking the carb to clean it properly, then replacing all replaceable parts with new should remove the carb from the suspect list of what is causing the problem. With any luck, it will fix the problem!
The other mystery is the appearance of blue smoke from the muffler when quickly opening the man butterfly valve. Usually, the engine responds by instantly increasing rpms. Right now, it sputters a bit, increases in rpm less instantly, and smokes a bit more than lightly until the engine rpms return to idle, at which time there is no smoke. Perhaps the smoke is from an ounce or two of Seafoam I added to one gallon of fuel. Oh, the fuel is 91 octane non-oxygenated fuel, containing zero ethanol. I have typically used this same fuel for nearly 40 years in this tractor without any problems before. Plus, it’s $5.19 per gallon, a dollar more than garden variety E10 which contains 10% ethanol.
As mentioned, I didn’t unscrew the port on the engine block where the pulse/vacuum line to the fuel pump is connected. The pulse line, according to the service manual, is supposed to be looped around the dip stick tube. It currently is not, but when I replaced the original Walbro 3000 all metal fuel pump with the new Walbro 3000 plastic pump, I made a new bracket so as to raise the pump about 5” above where the original pump was mounted. I did this to make sure the pump was mounted higher than the port on the block where the pulse line connects, as this is recommended in the manual to prevent oil from draining out of the engine block and working by gravity to the fuel pump through the pulse/vacuum line. If this happens, evidently problems occur, although the manual didn’t describe what those would be. I suspect extra oil into the pump, then mixed with gasoline on the way to the carb, ultimately ending up with issues similar to what I am experiencing. But, that’s just my guess as to what happens.
At this point, my focus will be on making sure the fuel system is working as it should. If that doesn’t yield positive results, then the electrical system will be next, with the coil being in the bullseye. As I mentioned before, it’s last on my list due to where it is located. It’s located above the flywheel which is accessible ONLY by pulling the engine from the tractor. On the Groundsmaster 52, this means removing the seat, the entire top cover of the chassis, the fuel tank again, followed by disconnecting the driveshaft, then using the engine crane (did I mention this is a heavy cast iron beast?) to lift the engine out after removing the engine mounts. Truth be told, it’s not a small task, so it’s dead last on the list of possibilities to check off as to what is causing the problem. I’ve been down that route twice before when the doggone Welch plug fell out of the carburetor and allowed dirt to be sucked into the engine, resulting in a rebore the first time and an entire new short block the second time. That was over 1000 hours ago, after we JB Welded the Welch plug in after the second disaster. I have one more re-bore possible on the second short block, but I’m hoping that is another 500 hours away.
Well, that’s where it stands today. Hope to have the carb kit installed by week’s end, and will report what the results are. Again, many thanks to everyone for all the great suggestions, some already implemented, some not yet. I’m waiting on a spark tester yet, too, as that suggestion was well taken and will be tried in due time.
Vvm
As for the fuel filter, as mentioned above, I have replaced it with what is recommended in the parts manual, using a metal filter about 1.5“ X 2.5” not counting the inlet & outlet tubes. It has an arrow showing the correct direction of flow. Gasoline flows readily through it. As for the little screens mentioned…I haven’t found any other than the two elbow fittings at the bottom of the tank. I couldn’t see inside the tank to tell whether or not they have screens on them, but maybe. Whether they do or not, gasoline flows freely from the elbows when the hoses are pulled.
If you haven’t seen the carb on these engines, it is a two piece carb, with the intake air entering at the top, but then diverted 90 degrees into the carburetor. This carb also has a Welch plug at the rear of it, about the size of a frost plug on a liquid cooled engine. The high speed needle/jet faces downward at an angle of about 50 degrees. The low speed needle/jet sits horizontally at the top of the carb. The float needle is independent of both, and is only accessible by disassembling the carb. So, here’s a strange observation. Normally, the float needle seats in a removable brass fitting. On this carb, none was present. Huh? Well, it wasn’t in there and the engine had been running fine, so this remains somewhat of a puzzle. How can a steel needle seat into pot metal? I will be putting on my magnifier hood this time around, to inspect that mystery more closely. With the kit not yet here, I don’t know if I will discover a brass seat included or not. If I do, then someone has been in there before and didn’t put it back in. But, if that were true, how would the engine run fine for many years without any issues. Also, how could a needle seat perfectly in molded pot metal without allowing the fuel bowl to overfill and leak? Soaking the carb to clean it properly, then replacing all replaceable parts with new should remove the carb from the suspect list of what is causing the problem. With any luck, it will fix the problem!
The other mystery is the appearance of blue smoke from the muffler when quickly opening the man butterfly valve. Usually, the engine responds by instantly increasing rpms. Right now, it sputters a bit, increases in rpm less instantly, and smokes a bit more than lightly until the engine rpms return to idle, at which time there is no smoke. Perhaps the smoke is from an ounce or two of Seafoam I added to one gallon of fuel. Oh, the fuel is 91 octane non-oxygenated fuel, containing zero ethanol. I have typically used this same fuel for nearly 40 years in this tractor without any problems before. Plus, it’s $5.19 per gallon, a dollar more than garden variety E10 which contains 10% ethanol.
As mentioned, I didn’t unscrew the port on the engine block where the pulse/vacuum line to the fuel pump is connected. The pulse line, according to the service manual, is supposed to be looped around the dip stick tube. It currently is not, but when I replaced the original Walbro 3000 all metal fuel pump with the new Walbro 3000 plastic pump, I made a new bracket so as to raise the pump about 5” above where the original pump was mounted. I did this to make sure the pump was mounted higher than the port on the block where the pulse line connects, as this is recommended in the manual to prevent oil from draining out of the engine block and working by gravity to the fuel pump through the pulse/vacuum line. If this happens, evidently problems occur, although the manual didn’t describe what those would be. I suspect extra oil into the pump, then mixed with gasoline on the way to the carb, ultimately ending up with issues similar to what I am experiencing. But, that’s just my guess as to what happens.
At this point, my focus will be on making sure the fuel system is working as it should. If that doesn’t yield positive results, then the electrical system will be next, with the coil being in the bullseye. As I mentioned before, it’s last on my list due to where it is located. It’s located above the flywheel which is accessible ONLY by pulling the engine from the tractor. On the Groundsmaster 52, this means removing the seat, the entire top cover of the chassis, the fuel tank again, followed by disconnecting the driveshaft, then using the engine crane (did I mention this is a heavy cast iron beast?) to lift the engine out after removing the engine mounts. Truth be told, it’s not a small task, so it’s dead last on the list of possibilities to check off as to what is causing the problem. I’ve been down that route twice before when the doggone Welch plug fell out of the carburetor and allowed dirt to be sucked into the engine, resulting in a rebore the first time and an entire new short block the second time. That was over 1000 hours ago, after we JB Welded the Welch plug in after the second disaster. I have one more re-bore possible on the second short block, but I’m hoping that is another 500 hours away.
Well, that’s where it stands today. Hope to have the carb kit installed by week’s end, and will report what the results are. Again, many thanks to everyone for all the great suggestions, some already implemented, some not yet. I’m waiting on a spark tester yet, too, as that suggestion was well taken and will be tried in due time.
Vvm
