CDogman's Airbox Mod & CO's

[SPORT]

Last November I too followed Cdogman's advice to modifying the Airbox. However, In March, right after the TPS recall was completed, the bike began running funny. I spent countless hours diagnosing the problem and even letting the dealer look at...to no avail.

I would often refer to my problem as a lean running miss and hesitation, but since I had already done the Barbarian mod +7, I did not consider messing with it and suggested it was a pinched o-ring causing some type of vacuum leak.

After replacing the battery, cleaning the ECU connector under the 'T' bar, replacing spark plugs, testing the TPS, completing a TBS, checking for vacuum leaks, testing spark plug leads, checking for diagnostic faults and trim the spark plug leads 1/4", I decided to up the CO's another +5 above the +7 I did after buying the bike several years ago. This seemed to be the fix!

I would say the bike is still a tad lean, but the engine has stopped surgin, hesitating and running rough. It now runs like it has the past couple years!

My question to you:

Has anyone who completed some type of airbox mod see the NEED to increase the CO's?

Can anyone explain how, or point me towards the info regarding how the CO's work?

Also, has anyone found the need to adjust CO's after a TPS replacement and how might this effect airfuel mixture?

For now, the problem seems resolved, but I would like to know more about how it fixed it.

Thanks

Sport

 

[SPORT]

Bump

 

[SPORT]

Here's a link to a discussion about CO's and how it's used. Ultimately, it seems unclear as to how Yamaha is utilizing CO's. However, most are in agreement that CO's are increased to eliminate the 'surging' that takes place with many stock FJR's.

another

Post # 4 & 5

As per Jon in Post #7:

JonApr 15 2008, 12:11 AM

In response to Roy's post:

"...The CO modification adjusts fuel mixture which is set very lean. Makes acceleration much smoother and the bike more responsive going through the gears. You can read about it on the Forum also."

 

[Wicked Webby]

Sport,

I would say that you could very well have been a bit lean. You really need to sniff the AFR of your bike (under load) to know.

No bike runs the exact same from the factory. The same model and year bikes (still run different) along with different climates

and elevations make for different states of tune. If you are going to open up your air box you really should have the bike sniffed/tuned

so that your not guessing.

WW

 

[SPORT]

If you are going to open up your air box you really should have the bike sniffed/tuned so that your not guessing.
WW

Yup! I agree. Workin on a way to have this done as we speak. It's just I've been fighting this problem right after having the TPS replaced and didn't think it was the CO's.

 

[Wicked Webby]

If you are going to open up your air box you really should have the bike sniffed/tuned so that your not guessing.
WW

Yup! I agree. Workin on a way to have this done as we speak. It's just I've been fighting this problem right after having the TPS replaced and didn't think it was the CO's.

This is a great tool for getting real World true road load results:

https://www.fjrforum.com/forum//index.php?s...hl=wicked+webby

Has worked great for me.

WW