ninjette.org - View Single Post - 2007 250ZZR Carb cleaning - any mods should I do while the carb is apart?

greg737 · October 24th, 2019, 02:01 PM

The ZZR250 doesn't have a 2-into-1 exhaust, right? Correct me if I'm wrong but the ZZR250 has the same exhaust configuration as the Pre-Gen bikes.

If you want to monitor a Pre-Gen bike's exhaust gas air/fuel ratio with one wideband O2 sensor (which is the usual configuration) you would have to install a 2-into-1 exhaust system and the O2 sensor would have to be installed downstream of the merge point for the individual cylinder headers.

But... if you do have a 2-into-1 exhaust system installed on your EX250 here's a picture of what I think is the perfect location to install a Bosch 5-wire Wideband O2 sensor.

This is a picture of the bottom of my EX250 which has an Area P full stainless steel 2-into-1 exhaust system installed. In the picture you can see that there's a gap of about 2.5 inches between the rear end of the engine oil sump and the forward pivot point for the rear suspension. That 2.5 inch gap is the perfect place to locate the O2 sensor.

I use a Bosch 5-wire sensor and Innovate Motorsports LC-1 wideband sensor controller.

If you have sharp eyes and really know what the bottom of an EX250 looks like you will notice that my Pre-Gen's oil sump looks like a Next-Gen oil sump because I retrofitted the large capacity Next-Gen oil-screen cover, which includes its own drain plug. This is an easy mod to do to a Pre-Gen engine and it has two advantages: it increases the EX250 engine's oil capacity and it makes draining the oil easier.

And you can also see that, as with all EX250 2-into-1 exhaust systems, I had to remove the bike's center stand because it (the center stand) cannot clear the 2-into-1 exhaust.

October 24th, 2019, 02:01 PM	#13
greg737 - Name: - Location: - Join Date: May 2009 Motorcycle(s): - Posts: A lot.	The ZZR250 doesn't have a 2-into-1 exhaust, right? Correct me if I'm wrong but the ZZR250 has the same exhaust configuration as the Pre-Gen bikes. If you want to monitor a Pre-Gen bike's exhaust gas air/fuel ratio with one wideband O2 sensor (which is the usual configuration) you would have to install a 2-into-1 exhaust system and the O2 sensor would have to be installed downstream of the merge point for the individual cylinder headers. But... if you do have a 2-into-1 exhaust system installed on your EX250 here's a picture of what I think is the perfect location to install a Bosch 5-wire Wideband O2 sensor. This is a picture of the bottom of my EX250 which has an Area P full stainless steel 2-into-1 exhaust system installed. In the picture you can see that there's a gap of about 2.5 inches between the rear end of the engine oil sump and the forward pivot point for the rear suspension. That 2.5 inch gap is the perfect place to locate the O2 sensor. I use a Bosch 5-wire sensor and Innovate Motorsports LC-1 wideband sensor controller. If you have sharp eyes and really know what the bottom of an EX250 looks like you will notice that my Pre-Gen's oil sump looks like a Next-Gen oil sump because I retrofitted the large capacity Next-Gen oil-screen cover, which includes its own drain plug. This is an easy mod to do to a Pre-Gen engine and it has two advantages: it increases the EX250 engine's oil capacity and it makes draining the oil easier. And you can also see that, as with all EX250 2-into-1 exhaust systems, I had to remove the bike's center stand because it (the center stand) cannot clear the 2-into-1 exhaust.