Suzuki GSX-R Motorcycle Forums Gixxer.com banner
1 - 5 of 5 Posts

·
Registered
2009 GSXR 600
Joined
·
9 Posts
Discussion Starter · #1 ·
I bought a k8 GSXR 600 that has a Yoshimura exhaust and the cat removed. Bike runs fine but gives the odd backfire when shutting off the throttle at high rpm. I contacted the previous owner a few days ago to see if he had the ecu flashed or a tune up done since the exhaust and decat was done. I've just had a reply back from him saying he didn't as he liked the crackling and popping the exhaust done so he didn't bother. I don't mind it either but my question is am I hurting the bike by not getting it tuned? I've had a quote for an ECU tune for €450 so I can get it done in a couple of weeks if really necessary. Any thoughts?
 

·
Premium Member
Joined
·
73,372 Posts
Yes, once you remove the cat you absolutely need to get it tuned.
 
  • Like
Reactions: Webblade

·
Premium Member
Joined
·
764 Posts
Dyno Tune is well worth the money.
Removing the stock exhaust lets the engine breath better. So with more air coming into the motor you need to add more fuel. Air fuel ratio is @ 12.5 : 1 across the whole rev range. This is what the tuner is trying to achieve. With your new exhaust your air fuel ratio may be as high as 16.5 : 1 (lean) in some places, NOT GOOD.
At certain revs it may create a rich mix (11.5 :1) witch will cause fuel to ignite in the exhaust.
It's fine to commute, just no full throttle. (y)
 

·
Registered
2009 GSXR 600
Joined
·
9 Posts
Discussion Starter · #5 ·
Dyno Tune is well worth the money.
Removing the stock exhaust lets the engine breath better. So with more air coming into the motor you need to add more fuel. Air fuel ratio is @ 12.5 : 1 across the whole rev range. This is what the tuner is trying to achieve. With your new exhaust your air fuel ratio may be as high as 16.5 : 1 (lean) in some places, NOT GOOD.
At certain revs it may create a rich mix (11.5 :1) witch will cause fuel to ignite in the exhaust.
It's fine to commute, just no full throttle. (y)
Thanks pal I'm booking it in for Saturday week. I'll go easy on the throttle I'm the meantime 👍. I just hope the guy I bought it from hasn't damaged anything as I don't know how long he's been driving it like that.
 
1 - 5 of 5 Posts
Top