[Cbrdude]

So my bike is a 2015 with around 25k... started noticing it backfiring in 5th n 6th.. mainly at around 85mph... I have to let off the throttle n gently roll back on to get it past 85...
It doesn't do it all the time but it's been getting more consistent...
It's a loud backfire too .. to the point it makes the bike jerk...
Doesn't do it at cruising.....I'm thinking the sparkplug is gone...
I run a slip on.. n usually run 87 reg or 91 non ethanol...
Bike runs good other then that... fires up 1st start...

 

[kiwi rider]

If it’s only doing it in the higher gears and at speed then that means something is breaking down under load as this is the highest load scenario on the engine. I would suspect it’s an electrical component. Start with the spark plug and go from there. Your coil is another likely suspect but also the HT lead between the two and also the spark plug cap.

 

[Cbrdude]

Thanks... I'm suspecting it's the plug... it's been rode hard but always kept oil in check and changed...
Also heard lots of pops n spits/ backfires... can foul the plug fast??

 

[kiwi rider]

In stock trim these bikes run pretty clean and are good on plugs but.... add a slip on and the stock tune goes out the window. Generally a backfire on decel with a slip on means its running lean. A look at the color of your plug will tell you.

 

[Cbrdude]

In stock trim these bikes run pretty clean and are good on plugs but.... add a slip on and the stock tune goes out the window. Generally a backfire on decel with a slip on means its running lean. A look at the color of your plug will tell you.

Deff lean!! Its white as a ghost ... but about 25k of long rides and backroad rips.. I'll spend the 25$ and replace it....
I figured the slip on wears the plug faster... guess you should expect to change or inspect around every 10-15K or whenever the backfire starts...

 

[kiwi rider]

Yeah that's pretty lean alright and most likely the source of the back fire. That slip on is making the bike run leaner than the ECU can compensate for. Ideally if your going to run a slip on you should get your ECU fuel maps altered to suit by flashing or add a piggy back fuel controller like a Power Commander, but most people dont because of the cost. Some are better than others though, my CBR ran fine with the Delkevic system I had on it. What brand is your slip on?

 

[Cbrdude]

Yeah that's pretty lean alright and most likely the source of the back fire. That slip on is making the bike run leaner than the ECU can compensate for. Ideally if your going to run a slip on you should get your ECU fuel maps altered to suit by flashing or add a piggy back fuel controller like a Power Commander, but most people dont because of the cost. Some are better than others though, my CBR ran fine with the Delkevic system I had on it. What brand is your slip on?

Running a Istunt no baffle... its a decent stainless steel pipe...
I can say I've always get the occasional stall out... mainly when blipping the throttle on take off ....
Yea it deff runs lean... I've considered the power commander but it's like 200 bucks... I hear it makes the bike more peppy....
I don't mind changing out the plug every now n then...
Just don't want any engine damage...
It don't smoke or anything abnormal... like i said it runs good ... it's never left me sitting in 5 yrs... I'd like to keep it that way!!...
Thanks for the info