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Is there something wrong? See the vid

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Super cool! :thumbsup:

I had a Fantic trials bike that did that occasionally.

How would it look at night - spectacular.

I guess that is why they make spark arrestors :ride:

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Might be runnig a touch rich. Or it is just a free flow exhaust. Anybody remeber that you can put a spark plug in your cars exhaust pipte and throw flames, as long as you don't have a catalytic converter :thumbsup:

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I think that's mickeydee here on tt

it is a rich slug of fuel/air exiting the cylinder when the throttle is closed after revving-it ignites in the pipe when it comes into contact with spark, hot parts or active radical ions.

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lol,yep ,my bike :thumbsup: .it was -10C and the pipe is red hot from idling for a while.unburnt fuel goes out of the ex valves and ignites.at night it periodically lets a flame out while i shift gears.it looks cool from behind :ride: .scares the hell out of the person on the sport bike thats eye level with the ex :applause:

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Micky,

I suspect that your bike runs lean instead of ritch. Lean fuel tends to burn a lot slower. The flame continues to expand while the exhaust ports are already open.

This also explains why your pipe is running red; it might not cool enough.

What do you think?

Noppy :thumbsup:

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Sounds like it is too rich. You can get your bike to do this if while you are running down the road; you hold the throttle in position partially open then kill the bike with the kill switch for a couple of seconds, while holding the throttle open, then turn the bike back on. It will shoot a flame out the exhaust as it ignites the raw fuel in the pipe. It should not happen with a spark arrester installed. If you chop the throttle it will not do it. With fuel going in but not igniting it does it & with no fuel going in it doesn't. So it is a too rich condition.

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Looks awesome! Not sure its good for the engine.... :ride:

I would suspect lean, its will be easy to tell. Pull the plug and take a look, black is rich and white is lean... :thumbsup:

Also, the only time I have every seen red headers it was lean, rich actually cools the bike down...

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You can get your bike to do this if while you are running down the road; you hold the throttle in position partially open then kill the bike with the kill switch for a couple of seconds, while holding the throttle open, then turn the bike back on. It will shoot a flame out the exhaust as it ignites the raw fuel in the pipe.

This is no bueno :thumbsup:

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its a combination of things going on at the same time.the temp was -10C theres snow and ice outside.i have an fcrmx carb on it so when i crack it with no load the acc pump squirts fuel in almost stalling the bike and its so cold that the fuel does not all vaporize so the unburnt fuel droplets pass through to the ex pipe which is red hot from idling for a while causing the fuel to ignite.it is a rich condition

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IMO this is perfectly normal. Just about every DRZ I've been around pops a little on deceleration, sometimes when short-shifting up.

There's always "some" unburned fuel in your exhaust, no matter your jetting. The reason it doesn't burn in the pipe with the throttle open is because there is a steady stream of oxygen-less exhaust flowing out. When you let off the throttle air floods back into the pipe between strokes thus allowing the fuel to be ignited by the next exhaust stroke.

If it happens when the throttle is opened wide, then you might have a jetting issue or, more likely, a leak in the pipe that is allowing air to get in.

As far as the red pipe, this sounds normal to me also, especily if it's dark out and especialy if you have an aftermarket head-pipe(thin wall stainless or Ti) that's the heat disipating, that's what they're for. It only take something like 600-700 deg to turn steel red and compressed gasoline burns at something like 1400(these may not be totaly accurate, but should be pretty close).

I wouldn't worry about it. It's cool.

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