Outdoor Power Equipment and Small Engines - backfire
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RICKT
11-25-02, 06:09 AM
THIS IS THAT OIL-LEEKING 17 HP I WAS WORKING ON. SHOULD GET THE GASKET TODAY. CLEANED THE OILY MESS OFF THE FRAME,NEW HIGH LIFT BLADES, DRIVE BELTS, ARG,ARG,ARG.
BUT EVERY TIME I SHUT HER DOWN WITH THE THROTTLE LOW, IT BACKFIRES,, HAS SINCE DAY-ONE. I BROUGHT IT BACK RIGHT AWAY(5 YEARS AGO), AND THEY SAID, THEY ALL DO THAT. GEE, NOONE ELSE I KNOWS TRACTOR DOES IT
BUT EVERY TIME I SHUT HER DOWN WITH THE THROTTLE LOW, IT BACKFIRES,, HAS SINCE DAY-ONE. I BROUGHT IT BACK RIGHT AWAY(5 YEARS AGO), AND THEY SAID, THEY ALL DO THAT. GEE, NOONE ELSE I KNOWS TRACTOR DOES IT
mastertekTN
11-25-02, 08:02 PM
some engines have a thing called anti backfire solenoid ( fuel solenoid ) yours must dot have this , try letting the engine run for 10 to 20 seconds at idle then shut off engine. someone told me one time to try shutting off at half throttle . you can let me know if this helps.
cheese
11-25-02, 11:00 PM
Does it only do it when shutting down at low speed or does it do it at any speed? The backfire is caused by unburned fuel being ignited in the exhaust. You could have a sliver of metal or some carbon in the exhaust port or muffler that gets glowing-red hot while running, and then when you shut the engine off, the fuel that continues to move through the engine while it is freewheeling to a stop gets ignited when it hits the exhaust.
RICKT
11-26-02, 06:47 AM
YEP, THATS THE DEAL ALRIGHT, IT BACKFIRES WHEN I SHUT OF AT IDLE. *CHEESE- YOU SUGGEST A HOT BURR IN THE EXHAUST- THE WHOLE BOTTOM OF THE MUFFLER GLOWS RED. IT ALWAYS HAS, JUST THAT YA CAN ONLT SEE THAT IN THE DARK.,OK THEN, SOUNDS LIKE THIS IS TIPICAL AFTER ALL. BUT LIKE I SAID, MY NEIGHBORS TRACTORS DONT BACKFIRE.
MASTERTEKTN- YER RIGHT, SOMEONE TOLD ME THAT TOO, BUT I ALREADY FIGURED IT OUT YEARS AGO. THATS WHAT I DO. (SHUT DOWN AT HALF THROTTLE). BUT YA KNOW WHEN YA COME TO STOP, YER FIRST INSTINCT IS TO PROTECT THE MOTOR, AND BRING HER DOWN TO IDLE. SO I DO FORGET NOW AND THEN.,FOR 1200 BUCKS YA'D THINK THEY'D ELIMINATE THIS PROBLEM. THANKS GUYS
MASTERTEKTN- YER RIGHT, SOMEONE TOLD ME THAT TOO, BUT I ALREADY FIGURED IT OUT YEARS AGO. THATS WHAT I DO. (SHUT DOWN AT HALF THROTTLE). BUT YA KNOW WHEN YA COME TO STOP, YER FIRST INSTINCT IS TO PROTECT THE MOTOR, AND BRING HER DOWN TO IDLE. SO I DO FORGET NOW AND THEN.,FOR 1200 BUCKS YA'D THINK THEY'D ELIMINATE THIS PROBLEM. THANKS GUYS