Air filter fire

Scout63

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I started my 72 with Amal 932s and factory air cleaner end paper filter this morning. It kicked back slightly before starting. I ran it for five minutes then shut it down, then noticed smoke from the side cover. I looked into the air cleaner and saw it glowing, then a small flame appear. I shot a small burst from my fire extinguisher into the air cleaner from each side and put it out. Has anyone experienced this with the stock setup before? I had the air slides down, which is unusual, but it was cold this morning. I’ll need to replace the filter and clean out the extinguisher powder before running it again. It could have been a lot worse.
 
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Never seen this with a paper filter, good thing that you had a fire extinguisher at hand, or much worse could have happened.
Make sure to clean the extinguisher powder from the bike thoroughly, it contains a salt which is very corrosive.
 
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Tornado

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Yes happened to my bike paper element. I was checking for vacuum leaks with brake cleaner spray while idling. Must of had a pop out the intake. Hit it with nearby windex to quench the ember glow.
 
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Yes happened to my bike paper element. I was checking for vacuum leaks with brake cleaner spray while idling. Must of had a pop out the intake. Hit it with nearby windex to quench the ember glow.

same happened to my Rocket 3 while doing the timing , blew back and fired up the air filter element. I always have an extinguisher close in the garage now.
 

concours

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Didn't the original paper air filter element come with a mesh molded into the inside of the gasket?

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napanorton

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That's how I got my first bike - a Triumph Daytona 500. The guy had "tuned" it but got the timing off. That, and a sticky tickler, turned it into a bon fire upon kick over. I picked it up cheap, I was only 17, and slowly put it back in running order. Everything rubber or plastic melted. One of the carbs sorta dripped down the manifold.
 

Scout63

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Never seen this with a paper filter, good thing that you had a fire extinguisher at hand, or much worse could have happened.
Make sure to clean the extinguisher powder from the bike thoroughly, it contains a salt which is very corrosive.
I hosed the residue off the bike right away but haven’t pulled the filter housing yet. I put the nozzle right against the screen and only gave it a half second on each side. The bike wasn’t running so hopefully I can just pull and clean the housing and replace the filter.
 
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I had one of these spitting-back fires on a Norton Jubilee, without even having an air filter.

Got the fire out and rode it around with scorched tank and seat.
 

grandpaul

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I had a heck of a fire with a Honda CB550 backfire, my wyfe jumped off the back, whipped off her blue jean skirt (she had on a slip), and started trying to help put it out. My Dad saw the commotion next door, ran into the kitchen and grabbed his fire extinguisher, it only gave a weak puff and fizzled. So, he frantically dug the one out of his suburban and it gave maybe a double-puff before it died. By that time, the flames were 6-8 feet high, with the two fuel spigots looking like little torches, feeding the flames. Finally, he dragged a garden hose over and put the melted mess out of it's misery.

I was able to rebuild it, at some cost...
 

Scout63

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Thanks GrandPaul. My second bike fire this year. Hopefully I’ve covered my allotment. I think now I’m going to pack a mini extinguisher in my backpack.
 

Tornado

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Baking soda is a method used for kitchen pots of oil catching fire. Does knock out the flames but also foams up and overflows everywhere. Don't ask how I know...
 
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