I should ask this on the Yamaha forum, but....

[radddogg]

...they're all dumb.



I've got a scorpion exhaust on my bike now and it sounds awesome. It even pops on overun which is

I have a question. It only pops if I don't quite fully shut off the throttle. Is this just because the butterfly flap is allowing a bit of air in to aid the deflagration? The reason I ask is that a simple mod that everyone does is to block off the exhaust air feed (a small pipe which allows filtered air to be drawn in to the exhaust to aid emissions). I can't see how this can possibly increase performance. Would unblocking it and thus allowing fresh air to be drawn into the exhaust increase the chance of the exhaust popping?

And before anyone says it....yes I am a

[pjm_morris]

Are you going to get a K&n on that thing next?

Also, do hellfrauds do neons for bikes?...

[radddogg]

Are you going to get a K&n on that thing next?

Also, do hellfrauds do neons for bikes?...

Why I oughta!!!

[pjm_morris]

I know a guy sellin' a set of chrome spinners for your particular bike, I'll let him know you are interesed.

They are replica's of the wheels that Valentino himself used in the 2007/08 season.....

[420gazza]

take the baffle out the exhaust and it'll pop even more

[syzsounds]

Are you going to break or damage anything if you just block the pipe and try it ?

[MarkCoupe]

Are you going to get a K&n on that thing next?

Also, do hellfrauds do neons for bikes?...

Why I oughta!!!

Image fail.

It should do yes.

[listie]

Are you going to get a K&n on that thing next?

Also, do hellfrauds do neons for bikes?...

Why I oughta!!!

Image fail.

It should do yes.

Making a habbit of these image fails Rob

[radddogg]

Are you going to break or damage anything if you just block the pipe and try it ?

No, I have already blocked it, what I'm asking is whether if I unblock it will this air feed increase the popping.

I guess the question I need the answer to is what causes the popping when I open the throttle slightly? Is the it the air or is it introducing extra fuel?

Are you going to get a K&n on that thing next?

Also, do hellfrauds do neons for bikes?...

Why I oughta!!!

Image fail.

It should do yes.

Making a habbit of these image fails Rob

Indeed, there is seriously something wrong. I've had loads the last week. Whats odd is they are random google images so its odd that they all come at once.

Hmmmm, I think I figured it out.

I just googled the same image at work and got this url

http://birthwithoutfearblog.com/wp-cont ... oughta.jpg

The url I linked last night from home was

http://1.2.3.9/bmi/birthwithoutfearblog ... oughta.jpg

My router died on friday so to avoid having to plug straight in the modem while we wait for the new router to come I've been wireless tethering off my phone. Perhaps the url difference is because the website is seeing my phone ip as a mobile and causing these issues.

Anyway, this is what I meant to put.

Why I oughta!!!

take the baffle out the exhaust and it'll pop even more

With the baffle out its just insanely noisy, its like a frickin Harley.

[98Ti]

Is your bike a 2 stroke? I know that performance exhausts on 2 strokes can make a massive difference to power, likewise if an exhaust is blowing they can make the engine run like crap... so perhaps as standard that air feed messes up the back pressure (all about presure pulses on 2 stroke isn't it?) so blocking it off might stop it losing that bit of power.

(No, I don't know WFT I'm talking about) (and, no I don't know what the popping is either )

[roverdave]

take the baffle out the exhaust and it'll pop even more

ill second that my bandit has no baffles atall just straight thru stubby can never fails to pop pop

[Bikernut]

"Clean air system" is what your on about i think.
Power gains from disabling this is gonna be very small on a 125.
The mighty ZX12R only gets about 3 bhp increase with this disabled.
Not sure how or why its popping on slight throttle openings,unless the scorpion can has upset the fuel map.

[radddogg]

Not sure how or why its popping on slight throttle openings,unless the scorpion can has upset the fuel map.

When I say slight throttle opening I mean a gnat's bollock. Not enough to make it rev. If I engine brake with the throttle fully closed then I get nothing. If I engine brake with the throttle slightly open then it pops. I want to know why? Is it the the introduction of air? Or am I slightly fueling?

[Punx0r]

Hang on, it's fuel injected? I'd assumed it ran a carb...

Injection systems generally cut off fuel completely when the throttle is closed and engine speed is above a certain point (usually ~1500rpm on car engines). Fuel + air in the zorst = bang, bang, bang.

I've currently got a small hole in my car's downpipe and it sometimes sucks in air on over-run and produces a variety of amusing noises.

[M17CH]

[alexcornwall]

my four stroke quad was the same dude, just the tiniest bit of throttle on the over-run, lovely