[yhzell83]

Alright guys, took my bike to Dyno and I got way lean reading above 9k rpm. Info on my bike:
09 Gsxr 750
OEM air filter change every 2 years or 20k km
2 years old battery

Just wondering what your thoughts on getting this kind of reading ?
Bad 02 sensor, bad fuel pump, battery ?
Help me out please.

 

[-JK750-]

Did you block the pair valve?

 

[yhzell83]

No I didn't. I use OEM spark plug, fine idle , SET valve working fine. No FI light. Bike pulls fine n smooth.
Will blocking the pair valve resolve this issue ?

 

[-JK750-]

That tells a lot about the dyno operator's know how if he/she/other didn't block the pair valve. That AFR reading is useless.

 

[yhzell83]

Hmm, most probably he didn't know about it. They are tuning low cc bike like scooter and moped most of the time. I should look for other tuner ?
That horse power reading bothers me.

 

[what?]

Actually, blcking the PAIR valve, on a system that is OEM only changes the reading the AFR gets- NOT the actual reading in the Combustion chamber, since the air is added in the exhaust port for better emissions.

I agree that NOT blocking a working PAIR system gives you a false/leaner AFR reading. Blocking a working system- as said- gives the more correct combustion chamber reading- which an accurate Combustion chamber reading is all you really need to 'tune' it anyway.
I wouldn't change anything. Look this Up, simply put a marble, of a plug in the hose where is sucks/gets the air from in the air cleaner box anyways,
and dyno it again.- I'll bet you're around 13 then.

 

[yhzell83]

Alright, i googled up about PAIR blocking. To confirm, I just need to stuck something in the tube hose connecting to the airbox or in the hole where it connect to the tube hose like in the pic, correct ? Do this mod require any further maintenance or does it mess up anything like bike idling ? Thanks in advance guys !!

 

[-JK750-]

Hmm, most probably he didn't know about it. They are tuning low cc bike like scooter and moped most of the time. I should look for other tuner ?
That horse power reading bothers me.

Did you get the right dyno sheet? Your bike should rev much higher than 12k. It also says GSX K5 1000 on the picture.

That's all you need to do to block the pair.

 

[yhzell83]

The reason they wouldn't want to rev higher than 12.5k rpm was due to lean reading on the bike and to be safe side. The HP reading was 99 @ 12.5k rpm, which normal with a restrictive silencer. I guess I can get higher HP reading if it was rev higher ?
Thanks JK750, I will block off the PAIR prior to dyno session next time. In the mean time, is it safe to ride above 10k rpm since the previous AFR was way off ?

 

[TheGeek]

Pay attention to how and where you block it. Don't want whatever you use as a plug getting sucked into the intake.

 

[yhzell83]

Marble should do the job, right ? For extra safety, i will zip tie the mid tube so that the marble wont budge. Can anyone comment on the HP reading ? Or I should do the PAIR block and dyno again, the HP reading should go up ?