[Mike323]

I recently upgraded to a Yoshimura slip on exhaust. Let start by saying it was an awesome upgrade. I did however, noticed that at during acceleration it sounds like there's a subtle static or something coming (leaves crackling) out of the muffler. I didn't hear it at first...but after a couple of hundred miles it came out of nowhere. I tighted everything, but its still there. Any thoughts?

 

[TheAOP]

My 2bros crackles when I roll off the throttle in 3rd.

 

[david92xj]

its just from the backpressure. my leo vince evo II does it A LOT but i love it lol.

nothing to worry about

 

[Matao87]

Same, my GP Corsa does also.

 

[eljay]

Just picture blue flames shooting out the tube every time you hear it and then smile about how awesome that would be.

 

[mattcbr250]

Yup. It's natural. You can eventually learn to control it. I like the crackle.

 

[jsonder]

Just picture blue flames shooting out the tube every time you hear it and then smile about how awesome that would be.

Especially at night on unlit back roads!

I can recall, in 1959, passing a car with my SOC 750 cc Crosley running straight pipe and the points set to prevent over revving. I had 2 feet of flame coming out the pipe as I passed an older dude and shifted into 3rd coming home from the midget races in Sun Prairie, Wisconsin.

 

[Mike323]

Please let me know...

Thanks

 

[gromit]

I recently upgraded to a Yoshimura slip on exhaust. Let start by saying it was an awesome upgrade. I did however, noticed that at during acceleration it sounds like there's a subtle static or something coming (leaves crackling) out of the muffler. I didn't hear it at first...but after a couple of hundred miles it came out of nowhere. I tighted everything, but its still there. Any thoughts?

All new vehicles come with catalytic converters which reduce hydrocarbons by adding fresh air to the unburnt gas in the exhaust and the converter eliminates the pollutants. By installing an aftermarket exhaust the catalytic converter has been removed. The unburnt gas and fresh air mixture is going into the new exhaust and you are getting a mini backfiring effect. There is no harm being done to the engine at all, some people like the sound and it is true on a dark night you might see some blue flame. The only possible negative thing is that the packing in your muffler could burn out a little quicker than normal. There is an air line that goes into a fitting on the top of the valve cover coming out on the left side (left side faring has to be removed). Pull the air line off, cap the fitting end and plug the open air line. No more air will go to the exhaust and the mini backfiring will stop. The ONLY purpose of that air line is to get air to the exhaust port. No harm done.

 

[Wynne G Oldman]

All new vehicles come with catalytic converters which reduce hydrocarbons by adding fresh air to the unburnt gas in the exhaust and the converter eliminates the pollutants. By installing an aftermarket exhaust the catalytic converter has been removed. The unburnt gas and fresh air mixture is going into the new exhaust and you are getting a mini backfiring effect. There is no harm being done to the engine at all, some people like the sound and it is true on a dark night you might see some blue flame. The only possible negative thing is that the packing in your muffler could burn out a little quicker than normal. There is an air line that goes into a fitting on the top of the valve cover coming out on the left side (left side faring has to be removed). Pull the air line off, cap the fitting end and plug the open air line. No more air will go to the exhaust and the mini backfiring will stop. The ONLY purpose of that air line is to get air to the exhaust port. No harm done.

Bang on. Couldn't have explained it better myself.

 

[SantaMonicaRy]

My Yoshi slip on does that too


Sent from my iPhone using MO Free

 

[Jubis]

LOL WHO SAID CRACKLE

I get the crackle on deceleration with a touch of throttle (watch le video), a mate told me it's something to do with the fuel being run lean to meet EPA or some such in Australia. It's probably that plus the catcon thing. I put the baffle on my pipe about 10 days ago, it's a lot quieter at lower RPM which is good as I do work nightshift and come home at 1-2am, it's a little harder to crackle now but still possible, and the pipe still sounds beautiful at high revs.