Popping on deceleration

hornett · 18 Jul 2013 at 20:36

I fitted a beowulf exhaust to my GSX650f sounds sweet but I am getting popping when I life off the accelerator.

To be honest it sounds awesome but I worries it could be causing me issues

wazza300 · 18 Jul 2013 at 20:49

Is it carbs or injection? It won't cause any issues but can cure it with a dynojet kit or pc3 if injected

hornett · 18 Jul 2013 at 20:53

injected, will it affect fuel efficiency

wazza300 · 18 Jul 2013 at 21:00

You might use a tiny bit more fuel,but I doubt you'd notice tbh

My zx6 pops a little bit not all the time tho,it upsets the fuelling with a straight through can/no baffles but won't damage anything

hornett · 18 Jul 2013 at 21:04

Nice, the bike is brandnew so haven't seen what the fuel is is like without it, might chat with the garage when it goes in for its first service

wazza300 · 18 Jul 2013 at 21:09

You want a power commander fitted then a dyno run and tuning to the new can,its expensive but will sort the popping

Draeger · 18 Jul 2013 at 21:10

Could be something as simple as a slight air leak at the joints. Check for a good fit. Is it a full system or just an end can change?.

I've got a twin high mount Renegade stainless system on the RSV, it pops and bangs on the over run and has been known to spit a few flames of ignited unburnt fuel out every now and then. Keeps car drivers on their toes.

hornett · 18 Jul 2013 at 21:12

its the end can and link pipe

Might check the joint at the bottom, I re tightened the first connection but maybe its not pushed down as far as it can go

wazza300 · 18 Jul 2013 at 21:21

Smear some exhaust paste round it then slip the can on and tighten it up

scottmorley · 18 Jul 2013 at 21:49

pops and bangs are good

(i'm childish, i know) shouldn't cause any issues. unless it's ridiculous then a re-map will help.
but if it's only an end can then it shouldn't be a problem. re-maps are only really essential when you get a full system.

hornett · 18 Jul 2013 at 21:54

scottmorley said:
pops and bangs are good (i'm childish, i know) shouldn't cause any issues. unless it's ridiculous then a re-map will help.
but if it's only an end can then it shouldn't be a problem. re-maps are only really essential when you get a full system.

Yer I love it, really gets me noticed which is a good thing on a bike. I was just worried I could be doing some damage

scottmorley · 18 Jul 2013 at 22:00

nah it'll be fine. mine pops and bangs nicely when you let off the throttle.
unless it's excessive, no harm will be done.
just enjoy it

ShakenNstirred · 19 Jul 2013 at 06:18

popping on the overrun is excess fuel in the exhaust pipe.
you're bike may have some form of emissions control like my bike.
mine has reed valves in the head between the exhaust valves and the headers that on the overrun open to let air in to the exhaust to help burn off any un-burnt fuel

eidolon · 19 Jul 2013 at 07:52

What about blocking off the pair valves?

http://www.moccsplace.com/images/pair/pair1.htm

Many people who have replaced their exhaust system with louder, lower backpressure pipes, have experienced an increase in the rapid popping/gurgling noises when throttling back and gearing down. With less backpressure, the exhaust vapors tend to load up in the system, and ignition of these vapors is sporadic and annoying. This popping occurs further down in the pipes, and is louder because of more open baffles, or no baffles at all. The quick fix for this is to simply "plug up" the air tubes that go into the cylinder walls, thereby preventing the air from getting there in the first place, thus, no "in-the-pipe" ignition. You may still experience some occasional popping, set off by the intense heat, but it is much less frequent.

Fireskull · 19 Jul 2013 at 09:17

wazza300 said:
You might use a tiny bit more fuel,but I doubt you'd notice tbh

90% of the time untrue, as already said its just unburnt fuel being ignited on the hot exhaust, so surely if you sort this out then you will be using less fuel

From experience and knowing plenty of others who have, a decent road map will actually increase your MPG, on my old 750 it was quite considerable.

Mine pops all the time, I love it, 3rd gear up to about 3/4 revs and let off she flames too

(Ive not had a custom map done yet..)

Dogbreath · 19 Jul 2013 at 14:17

Fireskull said:
90% of the time untrue, as already said its just unburnt fuel being ignited on the hot exhaust, so surely if you sort this out then you will be using less fuel

Popping on the overrun does not necessarily mean the engine is running rich, in fact lean mixtures (or air leaks in the exhaust) are far more likely to cause this problem, which is why air bleed systems for emissions like the Suzuki PAIR can cause this.

Simply replacing an exhaust can is not going to affect fueling on a closed throttle anyhow.

Fireskull · 19 Jul 2013 at 15:08

True true I forgot about the PAIR system good point!

My point was more just about remapping using more fuel

Griffo · 19 Jul 2013 at 16:21

My F800 used to do this a little, and the K1300S does it too, which sounds much nicer/more fun

wazza300 · 19 Jul 2013 at 16:21

surely you burn more fuel as theres no baffles to restrict the exhaust? wasted or non wasted fuel

bikers should laugh at fuel costs anyway

Dogbreath · 19 Jul 2013 at 18:55

wazza300 said:
surely you burn more fuel as theres no baffles to restrict the exhaust? wasted or non wasted fuel

The main reason for any fuel increase is more use of the wrist to enjoy the new noise level.

Restricting the exhaust will cause the engine to use more fuel for a given power output since pumping losses are higher.