Our 5+ year old tiller with a 5.5hp briggs-straton engine isn't starting up. We've done the burkholder choke, checked the air filter, carburetor, spark plug, and replaced the gas. The sparkplug ignites, and when I pull the cord with the filter off, puffs of white smoke come up, and a few times a little flame popped out too. Anything I can do before I take it to the repair shop?
Craftsman tiller w/ briggs engine won't start
- Thread starter myf150
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If you have a solid spark and good compression, then it's probably in the fuel system (carburetor, air filter, fuel line, or fuel). Have you properly cleaned the air filter or replaced it? Are fuel lines in good shape and tight fitting? Could water be in the carburetor fuel bowl? How did you prepare the tiller for winter storage? How often did you change the oil? What weight oil did you use?
Suggestion: take the spark plug out, squirt in some raw gas, replace the plug, and see if it runs.
[ August 07, 2005, 08:56 PM: Message edited by: TxGreaseMonkey ]
Suggestion: take the spark plug out, squirt in some raw gas, replace the plug, and see if it runs.
[ August 07, 2005, 08:56 PM: Message edited by: TxGreaseMonkey ]
My 10 year old lawnmower has a 6 hp Briggs & Stratton engine. It's supposed to use SAE 30, but I found it runs much better on Mobil 1 0W-40. It easily starts on the first pull.
I always store my mower in the garage, where water can't get into the fuel and where corrosion will be kept to a minimum. With plastic gas tanks these days, I keep the tank full year-round with gas. In the winter, I will take the mower out and start it once or twice. At the beginning of the season and after the engine is hot, I change the oil. A hot engine insures a rapid and complete drain. I only drain the oil through the drain plug.
I always store my mower in the garage, where water can't get into the fuel and where corrosion will be kept to a minimum. With plastic gas tanks these days, I keep the tank full year-round with gas. In the winter, I will take the mower out and start it once or twice. At the beginning of the season and after the engine is hot, I change the oil. A hot engine insures a rapid and complete drain. I only drain the oil through the drain plug.
We've done the fuel on the spark plug trick, but no luck there
Can't seem to find where the fuel line goes from the metal gas tank to the carburetor, and I haven't had a chance to get access to the carburetor.
As far as storage goes, the tiller is used I believe in the fall and spring, and it's left in the shed outside with fuel in the tank.
Can't seem to find where the fuel line goes from the metal gas tank to the carburetor, and I haven't had a chance to get access to the carburetor.
As far as storage goes, the tiller is used I believe in the fall and spring, and it's left in the shed outside with fuel in the tank.
I would drain all of the old gas from the tank, lines, and carburetor. Make sure no rust has developed in the tank. Pull the bowl off the carburetor and empty it. Refill with fresh gas and give it another try.
Since the tiller was stored outside, you may have rust on the flywheel, which affects the magneto pickup. Maybe your spark is not as strong as it should be. Take abrassive cloth and clean the pickup/stator.
Keep us posted. Hope these suggestions help and you get it running soon.
Since the tiller was stored outside, you may have rust on the flywheel, which affects the magneto pickup. Maybe your spark is not as strong as it should be. Take abrassive cloth and clean the pickup/stator.
Keep us posted. Hope these suggestions help and you get it running soon.
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All good suggestions above. Some basic diagnostics will help.
1. You are getting spark...
2. You say that you get smoke and the occasional flame.. So is the spark occurring at the correct time? Is the plug getting wet? It's not unheard of for the crankshaft/flywheel woodruff key to shear causing the ignition timing to be off.
3. Is the airfilter allowing enough air to support combustion? How dirty is it?
4. How long has the engine set since it last ran? as Molakule mentioned, the pulsejet carbs can have problems with their primitive fuel pumps. A dose of starting fluid might help to get the fuel pumping. The carb itself doesn't have a float bowl (if you indeed have a pulse-jet carb) but uses a small collection basket in the fuel tank. As the engine cranks; the vacuum differential in the intake plenum causes a spring resistive diaphragm to pump the fuel up and into the intake tract. If you're not pumping fuel then you possibly have a cracked diaphragm or a clogged pickup tube. There's a tiny screen at the bottom of the pickup tube which may be clogged with rust or other debris.
But, if you have the three basics (fuel, compression, and ignition) and they're occurring at the correct time then the engine will run.
1. You are getting spark...
2. You say that you get smoke and the occasional flame.. So is the spark occurring at the correct time? Is the plug getting wet? It's not unheard of for the crankshaft/flywheel woodruff key to shear causing the ignition timing to be off.
3. Is the airfilter allowing enough air to support combustion? How dirty is it?
4. How long has the engine set since it last ran? as Molakule mentioned, the pulsejet carbs can have problems with their primitive fuel pumps. A dose of starting fluid might help to get the fuel pumping. The carb itself doesn't have a float bowl (if you indeed have a pulse-jet carb) but uses a small collection basket in the fuel tank. As the engine cranks; the vacuum differential in the intake plenum causes a spring resistive diaphragm to pump the fuel up and into the intake tract. If you're not pumping fuel then you possibly have a cracked diaphragm or a clogged pickup tube. There's a tiny screen at the bottom of the pickup tube which may be clogged with rust or other debris.
But, if you have the three basics (fuel, compression, and ignition) and they're occurring at the correct time then the engine will run.
MolaKule
Staff member
Depending on the type of carbureteur, you may have varnish and rust particles blocking the pickup tubes, needle valves, etc. I.E., you have an air AND fuel flow problem.
In the pulsejet type of carbs, you most likely have a failed diaphram.
Again, how do you store the machine? Do you use fuel stabilizers or just let the fuel evaporate in the tank and carb??
In the pulsejet type of carbs, you most likely have a failed diaphram.
Again, how do you store the machine? Do you use fuel stabilizers or just let the fuel evaporate in the tank and carb??
If you have access to a compresion gauge then use it. Should go up to bout 40 on first pull and max out to over 90Pounds
If no gauge then pull on the rip cord with a steady draw several times. Do the same thing with other small engine and get the "feel" of compression.
Little white puffs of smoke coming back and a back fire or 2 says to me that a exhaust valve might be sticking.
If no gauge then pull on the rip cord with a steady draw several times. Do the same thing with other small engine and get the "feel" of compression.
Little white puffs of smoke coming back and a back fire or 2 says to me that a exhaust valve might be sticking.
Have you determined whether it's a fuel or a spark problem? Try starting with ether and see if it runs. More than likely it's a carb problem. Try a new sparkplug too.
try checking the flywheel key, also another problem (its a horizontal shaft right? ) the tanks rust, the pickups can fall off, and or clog, and the diaprahm can and will fail, but is easily replaced and will give gas, but too much when it does fail. also a sheared key will give spark, but will be off timing and will backfire either out the exhaust, or carb sometimes.
That's good information. Thanks.
I had compression on my B & S mower engine climbing only to 40 psi max.
I thought this was bad and condemned it. Bought a new mower. This one was 26 years old. I'll bet the new one won't last anywhere near 26 years.
dkcase, ya think ya got yo moneys worth from that Briggs?
I have a 12 year old Briggs and may do a test just to see how high it is.
Myf250, I have just been given a 4.5 HP Briggs lawnmower that is in nearly new condition that quit running and would only start after two squrts of the primer bulb then die. I took the carb and fuel tank off and removed the carb off the tank. I found pine needles and crud in the "Diafram/gasket". I cleaned it up and it runs fine now. DaveJ
Myf250, I have just been given a 4.5 HP Briggs lawnmower that is in nearly new condition that quit running and would only start after two squrts of the primer bulb then die. I took the carb and fuel tank off and removed the carb off the tank. I found pine needles and crud in the "Diafram/gasket". I cleaned it up and it runs fine now. DaveJ
Those motors only run about 6:1 compression, so 40 psi doesn't sound all that horrible. Still, 26 years is a helluva long time.
Compression should be about 90 lbs at best
40 lbs is low. If the motor won't start when you
pour gas in to the cylinder and you have spark
I would suspect the flywheel key as this throws
the timing completely off. Some times the shear
of completely and some times they just get bent.
40 lbs is low. If the motor won't start when you
pour gas in to the cylinder and you have spark
I would suspect the flywheel key as this throws
the timing completely off. Some times the shear
of completely and some times they just get bent.
Posting engine#'s would allow us to determine exactly which carb you have.
Most likely it's mounted directly on top of the fuel tank.
SOMETIMES, they can be "ressurected" with this method-
Remove air cleaner.
Pour about 1 teaspoons worth of gas in carb air intake. (remove gas can etc. away to safe area)
Try starting-
IF it's a fuel delivery problem, it should fire & run for a few seconds.
IF SO- repeat about 5-8 times.
SOMETIMES, that's enough to "pull a prime" through the carb and get things working again.
IF NOT, replace carb diaphragm. It's on the side of the carb, held on with 4? screws. It's about a $4? part.
Most likely it's mounted directly on top of the fuel tank.
SOMETIMES, they can be "ressurected" with this method-
Remove air cleaner.
Pour about 1 teaspoons worth of gas in carb air intake. (remove gas can etc. away to safe area)
Try starting-
IF it's a fuel delivery problem, it should fire & run for a few seconds.
IF SO- repeat about 5-8 times.
SOMETIMES, that's enough to "pull a prime" through the carb and get things working again.
IF NOT, replace carb diaphragm. It's on the side of the carb, held on with 4? screws. It's about a $4? part.
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