Stock bike (I think) shooting flames

[CheeseWheel]

Hi I’m new here, I have a 2009 St1300. I took off the mufflers to remove the wheel today as I am replacing the tires. As everyone does when they pull mufflers off I started it and gave it a few revs, I revved it and it shot probably a 6 inch flame out of the exhaust. Just wanted to know if this was normal. I’ve always noticed a small burble or backfire but wanted to make sure

 

[Chris09]

My 09 and my friends 06 seem to operate exactly the same, no burble or backfires [yet] smooth as sewing machines, in fact at idle warm, as fast as I can snap the throttle I can't detect any irregularity, others with experience on these problems will probably be asking you for a bit of background on it, how many miles so on. Welcome to the forum you'll get a lot of help here I'm sure.

 

[CheeseWheel]

My 09 and my friends 06 seem to operate exactly the same, no burble or backfires [yet] smooth as sewing machines, in fact at idle warm, as fast as I can snap the throttle I can't detect any irregularity, others with experience on these problems will probably be asking you for a bit of background on it, how many miles so on. Welcome to the forum you'll get a lot of help here I'm sure.

Thanks for the warm welcome, I hope I get lots of knowledge from this forum

 

[SMSW]

As everyone does when they pull mufflers off I started it and gave it a few revs, I revved it and it shot probably a 6 inch flame out of the exhaust.

Only 6"? Mine does 10"

Methinks you are mistaken. I've never done that on any bike I owned. Now, a few years ago, (in 1971, to be exact) I tore down and rebuilt my Triumph 650 in the basement of the rental house we were living in. Anxious to see if the engine worked after complete disassembly, I poured gas in the tank and with NO headers, exhaust pipes whatsoever, got on the bike and stood on the starter. This was a very clever move - the steam boiler was a few feet away and firing merrily - this was late winter - but the bike started on the first kick. The roar in that small basement nearly blew my ear drums out, and I know I bettered your 6" flames. i was pickled tink.

 

[drrod]

Normal. Now all you have to do is figure out how to do with the mufflers connected

 

[docw1]

I took off the mufflers to remove the wheel today as I am replacing the tires.

Gosh. I never remove the mufflers to remove the wheel. I just rotate them out of the way. In 140,00 mies, I don't think they've ever been off.

 

[Kevin_56]

Gosh. I never remove the mufflers to remove the wheel. I just rotate them out of the way. In 140,00 mies, I don't think they've ever been off.

10 seconds and they are totally out of the way. You have already removed the support bolts and loosened the muffler clamp. Pull them off and set aside. Now I can scoot around and not have to have them in my way. Really easy to polish them before reinstalling. As long as you get the job done, then it is a job well done, no matter how we do it,.

 

[Larry Fine]

Flame from the exhaust is unburnt fuel.

 

[diferg]

welcome to the forum. enjoy your new ride. The exhaust will "burble" if you decelerate with the throttle slightly cracked open.

 

[Andrew Shadow]

Every gasoline internal combustion engine shoots flames out of the exhaust. Whether or not you see it is dependent on how much exhaust pipe is still in place between the cylinder head and the point where the exhaust has been removed. The shorter that distance, the more flames that you will see.

 

[drrod]

No matter how cool it would be to have the ST spit flames from its mufflers, it would not be Porche 918 cool!!

 

[CheeseWheel]

Wow I didn’t realize how many replies I got! I was waiting for an email but never got it. I’m glad it’s normal, I did some research on it too and found it’s somewhat normal but thank you all for the info!

 

[Chris09]

Unless they're the Calgary Flames,[myself, I'm from Edmonton and I watched Wayne Gretzky redefine the game in one of his last WHA games] and unless you have a cam with serious overlap [mostly] duration and lift, flames from the exhaust are raw HCs` that didn't burn in the combustion chamber, this is raw fuel that achieved / maintained ignition upon contact with oxygen as it leaves the engine; hey buddy, can you spare an exhaust valve, [if you wanna call it that}; in the otto engine, substantially all of the charge is burned at what? during some small range 15 degree range [haven't even thought of this ____ since I rebuilt my first 396 fifty odd.... ahh, another story] on the fourth stroke [who cares] however, my ]10:1 ?] two stroke V4 110 2 Stroke does not have flames shooting out of the exhaust valves; I mean, don't get me wrong, I've never been to Kansas either, but I'm pretty sure it's there.
You don't get 110 hp / 1267 cc / linear torque / linear horsepower / 40 odd miles to the gallon over catalytic converters... and a free flame thrower.

 

[jfheath]

Burbling on the over-run is quite common on the pre-2008 models (based on my testing sample size of one). But the Post 2008 models (based on a different sample size of one) it isn't as evident.

However, sometimes on narrow mountain roads I get caught out thinking that there is a big powerful sports bike riding close behind me, and it turns out to be the echo from my own exhaust burbling away as I back off the throttle on approach to the next bend.

But never, ever a backfire.

 

[STRider]

Flames or not, I don't think what happens at the exhaust outlet of a modern, closed loop (or mostly closed) internal combustion engine when the mufflers and catalytic convertors are removed from the system are any indication of anything. The lack of back pressure, and resulting confused readings from the O2 sensor, etc... make for a thoroughly non-standard operating state and I wouldn't be surprised if monkeys flew out of the open pipes. Okay, I'd be surprised. And intrigued.

 

[ad.hom]

I recently replaced the downpipes on my '02... (for those that are interested, delkevics were much cheaper than OEM, but I still have the OEM mufflers, for now...)

Every gasoline internal combustion engine shoots flames out of the exhaust.

I can confirm that my 02 has a gasoline powered internal combustion engine.

 

[Andrew Shadow]

I can confirm that my 02 has a gasoline powered internal combustion engine.

Can't say that I am surprised.
I would have been surprised to hear that it was equipped with a diesel, or propane, or natural gas internal combustion engine.