02 Honda Cbr 600fs backfire

[moran]

Bought a cbr 600fs a few weeks ago and has been driving fine other than the common CCT rattle

Replaced the cct yesterday and noticed the bike has started backfiring on deceleration but only when its about 2-3k rpm. Wondering does any other owners bikes do this as a standard bike?

 

[Nicky]

You've likely altered the timing slightly, causing it to backfire on the overrun.

 

[moran]

Yea thats what i thought. I assume the new cct has returned the bike to correct timing taking up the slack so hope thats the way it should be as it still drives perfect

 

[Nicky]

What year is she?

 

[moran]

2002 first of the fuel injection ones i think

 

[mikey]

My Honda Hornet would spit and bang on the overrun, as my Suzuki, KTM and now my Triumph do. Sound is amplified with an aftermarket can. Down to the pulsed air system on bikes which basically bleeds fresh air into the exhaust ports on overrun as an emissions control. Once I removed the pulsed air valve on the Suzuki she stopped doing it. Obviously if it's churning out black smoke and flaming out a standard can it needs investigation but other than that it's perfectly normal.

 

[moran]

Cheers buddy! Its quite a loud pop as your slowing off but no flames or black smoke all seems fine

 

[fabiostar]

or a leak in the exhaust pipework causes it.

 

[Daz500]

An exhaust leak around the gaskets is where I'd be looking. That and double checking the timing.

 

[fabiostar]

be very carefull before you start ripping into it with spanners checking the timing. if the timing has slipped somehow it would run bad all through the rev range. at a guess, what you are hearing is air leaking into the pipework or slight over fuelling and its getting burnt of in the exhaust causing the pops and bangs.

 

[TalkToFrank]

I've the same bike, the pancake part of the exhaust is known to rot on them just under the fairing, but didn't make mine noticeably loud or obvious, but I did get backfiring and a few flames! You can buy a new manifold on eBay around £200 for a stainless but I just welded mine, was worse than I thought when I looked at it and probably won't last as long and if I was to go through it again I would have bought the stainless items!

Tip:- heat the bike up before taking the exhaust off because the studs are notorious for snapping. Wear heat resistant gloves! Lol

 

[moran]

The mrs is buying me a delkevic slip on for crimbo so ill check it out then when i fit it, as they also supply a manifold so if it is then ill jusr upgrade to that. Cheers bud!

 

[fabiostar]

start the bike up on a nice cold early morning and as it heats up you will see the condensation blowing outa any holes in the pipe is a handy way of checking for leaks.

 

[moran]

Yea thought i seen sone on sat afternoon but think it was just steam due to the heat as the bike warmed up