Question

[Slowe Rider]

I have a Hyosung gt650, just fitted new exhaust in screaming demon.

Whenever I let go the throttle too much or down gear too fast, there is popping noise, as in something exploiting coming out my exhaust.

I was just wondering; why it is doing that, and does it do any damage to my bike?

please help thank you for time and effort

[Semi]

That's unburnt fuel.

[Slowe Rider]

so, it wont do any damage to the bike at all?

[Crashlington]

i like the popping sound

better when you're blowing flames though

[Semi]

no, it wont

[BigTim]

so, it wont do any damage to the bike at all?

It'll damage the exhaust baffles over time.
Does the Hyo have any sort of emission-reducing air introduced to the exhaust? I know on the later Suzukis they have the PAIR valve (pulsed air intake reed), which pumps air from the airbox into the exhaust, which causes popping when you roll off the throttle, when aftermarket mufflers are fitted.
I've blocked mine off because it was popping like crazy and I didn't want to fuck a nice new muffler.

[Moorby]

A 675 with a Jardine does it really well

[r0gue]

i like the popping sound

better when you're blowing flames though

exactly why its cool to sit behind rob (speedtrip) at night

the flames that triple put out are awesome

[STEEDS]

I have a Hyosung gt650, just fitted new exhaust in screaming demon.

Whenever I let go the throttle too much or down gear too fast, there is popping noise, as in something exploiting coming out my exhaust.

I was just wondering; why it is doing that, and does it do any damage to my bike?

please help thank you for time and effort

If it gets annoying you could take your bike somewhere to get the Carbies tuned so it isnt running so rich... that will sort out the fuelling issue and therefore stop the pop....

Flames do rock tho

[Barfridge]

The ER6 does it all the time, nice flames too. Which might explain why the exhaust is stuffed, small explosions do weaken things over time

[Semi]

Maybe its stuffed because its a 2 bros pipe?

[Semi]

It'll damage the exhaust baffles over time.
Does the Hyo have any sort of emission-reducing air introduced to the exhaust? I know on the later Suzukis they have the PAIR valve (pulsed air intake reed), which pumps air from the airbox into the exhaust, which causes popping when you roll off the throttle, when aftermarket mufflers are fitted.
I've blocked mine off because it was popping like crazy and I didn't want to fuck a nice new muffler.

Hrmm, thanks for the info timothy. I will have to look into that on my bike, it is popping a little.

[Retro]

Couple of things here:

New exhaust may mean you're running lean, as in not enough fuel in the fuel/air mix. A tune at the shop may fix this by adjusting the mix screw on the carby or a re-jet. You may be able to score someone here with the talents needed to sort this...but unless you're 100% confident in your carby adjusting skills or someone elses..get this done in the shop.

Also, as a new exhaust has been fit check for any leaks around the manifold or any connections. If there's a leak it will manifest as a popping on decel. If you take something like a lit match, blow out the flame and move the smoke around the connections (running the bike at idle this is) look to see if the smoke gets 'sucked into' the exhaust fittings...that's a leak!

Just fit a new system on my bike and I know the front cylinder has a leak at the manifold...waiting for things to 'soot-up' a bit and see if that helps but in the meantime I get the popping on decel most times.

[BigTim]

Hrmm, thanks for the info timothy. I will have to look into that on my bike, it is popping a little.

If yours has the same PAIR valve shite (I'd guess it does), you can either buy block-off plates to remove the whole valve assembly, and then have to stuff around wiring in a resistor to avoid the FI warning, or you can just find the hose it uses for intake from the airbox and plug it.
I machined up a little tapered bung to jam in the hose, but a marble and some silicon would work just as well.

[Xuaxace]

My ZZR does some nice little pops.

It Even shot up flames once (true story)