I have an '09 4RT "Repsol" and am going to be riding through elevation changes of 6-9000 feet. If I do the complete "full power" mod (factory), it involves exchanging the header for one without a catalytic converter and removing the oxygen sensor (no port).

Does the removal of the sensor make it an open system?

Will the fuel injection system have difficulty adjusting for significant climatic changes? Quickly or at all?

Does it affect fuel consumption?

Thanks.

Cat converters Oxygen sensors Stop the world i want to get off

Gday, the O2 sensor basically acts as a final check for the ECU to see if it has the mixture correct. Removing it will make the system "Open Loop" in that there is no "final check off". The System will adjust for altitude and air temperature quickly. It may affect fuel consumption but not greatly so. It will increase exhaust emissions.

HTH,

Cheers,

Stork

I have an '09 4RT "Repsol" and am going to be riding through elevation changes of 6-9000 feet. If I do the complete "full power" mod (factory), it involves exchanging the header for one without a catalytic converter and removing the oxygen sensor (no port).

Does the removal of the sensor make it an open system?

Will the fuel injection system have difficulty adjusting for significant climatic changes? Quickly or at all?

Does it affect fuel consumption?

Thanks.

Has something changed with the 09 models? I didn't think there was an O2 sensor or catalytic converter on these motors. I understood the throttle body monitored intake air pressure and temp (and I'm not sure about the pressure measurement), an O2 sensor would have to be on the exhaust side wouldn't it?? My 06 bike certainly doesn't have any sensor or converter on the exhaust side.

Is somebody having a lend of us with this question??

Hopefully I am getting a clearer picture. If the previous models did not have the O2 sensor and the throttle body does the monitoring of air density to create a closed loop system, then the O2 sensor is simply for emissions reduction (minor as it may be)? If so, then the catalytic converter with O2 sensor were obviously included solely for use with the street legal kit (not valid in Canada or the US).

Thanks.

Hopefully I am getting a clearer picture. If the previous models did not have the O2 sensor and the throttle body does the monitoring of air density to create a closed loop system, then the O2 sensor is simply for emissions reduction (minor as it may be)? If so, then the catalytic converter with O2 sensor were obviously included solely for use with the street legal kit (not valid in Canada or the US).

Thanks.

You are right only for road use (it is new from the 2009 models). Thats why they have a kit to change/transform the bike for competition use

http://members.quicknet.nl/sw.zeinstra/4RT...ll_power-uk.pdf

I've ridden a few trials at altitude, maybe 2000-2500ft on a pretty much std 2006 4rt, the bike seemed to adjust itself pretty much ok. There was some loss of power, particually at the top end where it didn't seem to rev out.

To try rectify the issue and to get more air into the airbox and through the throttle body, i cut away the airbox lid giving it a much larger mouth and opened up the rubber manifold to the throttle body. Yes, it did bring more of the top end back but at the expense of running too hot and pre-detonating after 10mins of riding, like it was suffering from fuel starvation.

I returned the bike to normal and after 30mins of riding the lack of umph wasn't really noticable

Gday, keep in mind that air is less dense at altitude and that power loss is inevitable. Mixtures do need to be adjusted and engines actually mix air and fuel by weight, not by volume. Turbo or supercharging is the only answer. Not too practical on a trials bike! It makes sense that the O2 sensor and cat converter are for a road kit to meet exhaust emission requirements. Most jurasdictions would require this these days.

Cheers,

Stork

You are right only for road use (it is new from the 2009 models). Thats why they have a kit to change/transform the bike for competition use

http://members.quicknet.nl/sw.zeinstra/4RT...ll_power-uk.pdf

Thanks Fantic303 for the link. I had no idea that current models had these changes, no wonder the price of the bike keeps going up!!

Is this fitted to all 09 bikes or is it country specific?