Riddle me this. Riddle me that. BACKFIRE?

spldart · 07-17-2015, 09:41 PM

Had the bike for a few thousand miles now.
Today i left work and got 4 miles down the freeway and I let the throttle down,
not off just down, and got a backfire out the exhaust.
First and only backfire.
Bike ran another 20 miles normal power, normal idle, normal start.
Heck. I just ran back to grocer store to hit redbox and grab a couple dvd's and
back home. Perfect operation.

I have been doing constant checks on compression and reading the plug.
Plug read says my mixture is great.
My mileage is mid 70's so yeah. Running good.
Got it back to easy start except when it's insane hot out. But otherwise it always
turns over less than a second.
Factory exhaust and I haven't disturbed it.
Bolts at exhaust/head are still tight and i don't hear a leak.

I'd understand if i had disturbed the exhaust and not used a fresh gasket.
I'd understand if I was having mixture issues.
But an engine that runs and starts great belting out a serious one time only
bark?

Any thoughts?

"edit" i run middle octane gas. Just because it's so hot and higher octane resists predetonation better.
I'm not running premium however. Just one step above the cheap stuff.

blaine · 07-17-2015, 10:16 PM

May have just a little to much fuel in the exhaust from the heat..Happening once......I wouldn't worry about it much.

5th_bike · 07-18-2015, 12:34 AM

Blaine is right, no worries.

Just a thought - what happens when you close the throttle a bit and the rpms are still high, is the air goes faster through the carb and drags some extra fuel to the cylinder. Not all of that may have burnt in the cylinder. Thus.

Water Warrior 2 · 07-18-2015, 01:41 AM

Don't sweat the small stuff. When you hear a big bang and pieces fall off you can sweat. Ride and enjoy the wind.

spldart · 07-31-2015, 12:38 PM

Found it....
I've been hearing a bit of sputter especially slowing down. I had a tiny exhaust leak left side pipe.
Prolly the cause of the backfire too.

07-17-2015, 09:41 PM	#1
spldart Senior Member Join Date: May 2015 Location: Stafford, Texas Posts: 604	Riddle me this. Riddle me that. BACKFIRE? Had the bike for a few thousand miles now. Today i left work and got 4 miles down the freeway and I let the throttle down, not off just down, and got a backfire out the exhaust. First and only backfire. Bike ran another 20 miles normal power, normal idle, normal start. Heck. I just ran back to grocer store to hit redbox and grab a couple dvd's and back home. Perfect operation. I have been doing constant checks on compression and reading the plug. Plug read says my mixture is great. My mileage is mid 70's so yeah. Running good. Got it back to easy start except when it's insane hot out. But otherwise it always turns over less than a second. Factory exhaust and I haven't disturbed it. Bolts at exhaust/head are still tight and i don't hear a leak. I'd understand if i had disturbed the exhaust and not used a fresh gasket. I'd understand if I was having mixture issues. But an engine that runs and starts great belting out a serious one time only bark? Any thoughts? "edit" i run middle octane gas. Just because it's so hot and higher octane resists predetonation better. I'm not running premium however. Just one step above the cheap stuff. Login or Register to Remove Ads Last edited by spldart; 07-17-2015 at 09:48 PM.
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07-17-2015, 10:16 PM	#2
blaine Senior Member Join Date: Feb 2010 Location: P.E.I. Canada Posts: 3,784	May have just a little to much fuel in the exhaust from the heat..Happening once......I wouldn't worry about it much. __________________ If at first you do succeed, try not to look surprised.
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07-18-2015, 12:34 AM	#3
5th_bike Senior Member Join Date: Oct 2007 Location: HoCo, Maryland Posts: 1,349	Blaine is right, no worries. Just a thought - what happens when you close the throttle a bit and the rpms are still high, is the air goes faster through the carb and drags some extra fuel to the cylinder. Not all of that may have burnt in the cylinder. Thus. __________________ 2005 "Saturn Black", stock + tach Login or Register to Remove Ads
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07-31-2015, 12:38 PM	#5
spldart Senior Member Join Date: May 2015 Location: Stafford, Texas Posts: 604	Found it.... I've been hearing a bit of sputter especially slowing down. I had a tiny exhaust leak left side pipe. Prolly the cause of the backfire too. Login or Register to Remove Ads
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07-18-2015, 01:41 AM	#4
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	Don't sweat the small stuff. When you hear a big bang and pieces fall off you can sweat. Ride and enjoy the wind.
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