Autralian Restricted model MT07. The hidden restrictor. Removal
I used my original ECU that was sent away and got remapped/reflashed.
I did not try running the bike after removing the airbox restriction with the original ECU setup as the bike was running lean with all the other mods already.
Current mods are, airbox restriction removed, throttle restrictor removed, O2 sensor disconnected, K&N filter with no snorkel & Ixil pipe with no CAT. (no baffles & internal baffle drilled out)
The bike goes great, yet to put it on a dyno.
I did not try running the bike after removing the airbox restriction with the original ECU setup as the bike was running lean with all the other mods already.
Current mods are, airbox restriction removed, throttle restrictor removed, O2 sensor disconnected, K&N filter with no snorkel & Ixil pipe with no CAT. (no baffles & internal baffle drilled out)
The bike goes great, yet to put it on a dyno.
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Thanks for that Calvary.
Yeah that was my thoughts as well. Opening up the flow with it running lean was a bit iffy. The ECU would probably have adapted but a bit risky.
Does the Ixil have a 100 grade cat cylinder or a 200 or400. If it has a 100 it should have no effect on the output and will help cut the noise a bit without making it sound dull. Some dyno figures I have seen for Akra ( both Ti and carbon ones) and another showed power LOSSES when removing the Db killer) I suspect that is because it reinforces the out of phase pulse problem (90/270 deg crank) of the 2 into 1 exhausts. The baffles may dampen the transients so they don't interfer as badly. I would be interested to see the dyno results with and without the db killer on yours to see if the Ixil is the same.
Why disconnect the O2 sensor if it is remapped? Unless it was disconnected in software, in NZ, where you have big differences in humidity and temp ( at the cold end), it would help keep it fuelled right overall.
If you just remove the snorkel it makes no measurable difference . I tried it on the dyno both with and without and that was with the K&N. The stage 2 cover should make a little difference though or make a non-PLATE cover. Without the snorkel, the cover is simply a hole in plate. From a flow point of view this is a bad as it gets. I made a proto sculptured inlet topography, which is an improvement, but will make a higher smoother one at some stage. See photo.
Yeah that was my thoughts as well. Opening up the flow with it running lean was a bit iffy. The ECU would probably have adapted but a bit risky.
Does the Ixil have a 100 grade cat cylinder or a 200 or400. If it has a 100 it should have no effect on the output and will help cut the noise a bit without making it sound dull. Some dyno figures I have seen for Akra ( both Ti and carbon ones) and another showed power LOSSES when removing the Db killer) I suspect that is because it reinforces the out of phase pulse problem (90/270 deg crank) of the 2 into 1 exhausts. The baffles may dampen the transients so they don't interfer as badly. I would be interested to see the dyno results with and without the db killer on yours to see if the Ixil is the same.
Why disconnect the O2 sensor if it is remapped? Unless it was disconnected in software, in NZ, where you have big differences in humidity and temp ( at the cold end), it would help keep it fuelled right overall.
If you just remove the snorkel it makes no measurable difference . I tried it on the dyno both with and without and that was with the K&N. The stage 2 cover should make a little difference though or make a non-PLATE cover. Without the snorkel, the cover is simply a hole in plate. From a flow point of view this is a bad as it gets. I made a proto sculptured inlet topography, which is an improvement, but will make a higher smoother one at some stage. See photo.
Hi Greg, I'm not sure about the CAT grade, but I did see a similar write up as you mentioned that with both the Cat in and the baffles a guy with a FZ09 got better numbers.
The O2 sensor disconnect was recommended by the guys that did the reflash of the ECU to prevent the sensor from trying to make any adjustments. Thanks for the info on the intake; yes that is something that I may change again at a later point by either removing the box altogether and just putting pods on or think of modifying the inlet as per your idea.
I have to be honest though I like the loudness and tone of the pipe, the low down power is so good through the bends that staying with the big bikes has not been an issue since the changes. Having a dyno would have been great but unfortunately that was not possible while I was making the changes. Keep us posted/updated on any other idea or changes that you do make in the future.
One thing I have been trying to find out is how much can be done to the head and the block before changing the injectors & or throttle bodies, nice project bike to play with and modify very easy to work with.
The O2 sensor disconnect was recommended by the guys that did the reflash of the ECU to prevent the sensor from trying to make any adjustments. Thanks for the info on the intake; yes that is something that I may change again at a later point by either removing the box altogether and just putting pods on or think of modifying the inlet as per your idea.
I have to be honest though I like the loudness and tone of the pipe, the low down power is so good through the bends that staying with the big bikes has not been an issue since the changes. Having a dyno would have been great but unfortunately that was not possible while I was making the changes. Keep us posted/updated on any other idea or changes that you do make in the future.
One thing I have been trying to find out is how much can be done to the head and the block before changing the injectors & or throttle bodies, nice project bike to play with and modify very easy to work with.
" One thing I have been trying to find out is how much can be done to the head and the block before changing the injectors & or throttle bodies, nice project bike to play with and modify very easy to work with. "
I so agree. This bike is a seriously exciting motorcycle. Small, light(ish), suspension fixeable, good riding position and ability to modify that, unusual and very workable engine config, great stiff swinarm, Lots of possibilities.
It reminds me of when the RD350LC came out....Possibility of a giant killer.
I so agree. This bike is a seriously exciting motorcycle. Small, light(ish), suspension fixeable, good riding position and ability to modify that, unusual and very workable engine config, great stiff swinarm, Lots of possibilities.
It reminds me of when the RD350LC came out....Possibility of a giant killer.
UPDATE!
You are unlikely to damage the bike by opening it up. Damage usually comes for the bike ending up lean at high airflows( revs) and detonation resulting from the lean mixes.
I have just been checking all the AFR graphs I can find and ALL bikes in all configurations even stock or adjusted afr for most of the rev ranges run rich to VERY RICH from 9000-10500. I am still looking for a PCV set to see if they do as well. You won't damage the motor from lean mix doing the following from what it can see doing the following:
Standard
Throttle stop removed
Any airfilter change
snorkel removal
Any better flowing exhaust
Intake restrictor removal
ECU reflash
Any combination of these.
NOTE: I am not saying you will get better or worse power. I am saying that the MT07 runs rich from 9000-10500 increasing with revs. Ie it is richest at max rev limit! It aint gonna detonate or burn valves. In fact all you do at those revs is actually waste fuel.
I need to find out why is runs so rich ( ie so rich it is surprising it even runs. A bit of HP lurking up there still.
You are unlikely to damage the bike by opening it up. Damage usually comes for the bike ending up lean at high airflows( revs) and detonation resulting from the lean mixes.
I have just been checking all the AFR graphs I can find and ALL bikes in all configurations even stock or adjusted afr for most of the rev ranges run rich to VERY RICH from 9000-10500. I am still looking for a PCV set to see if they do as well. You won't damage the motor from lean mix doing the following from what it can see doing the following:
Standard
Throttle stop removed
Any airfilter change
snorkel removal
Any better flowing exhaust
Intake restrictor removal
ECU reflash
Any combination of these.
NOTE: I am not saying you will get better or worse power. I am saying that the MT07 runs rich from 9000-10500 increasing with revs. Ie it is richest at max rev limit! It aint gonna detonate or burn valves. In fact all you do at those revs is actually waste fuel.
I need to find out why is runs so rich ( ie so rich it is surprising it even runs. A bit of HP lurking up there still.
davisribot
New member
Hi gregjet, sorry for resurrecting an old post.
You seem to be the best person to ask as you have quite a bit of knowledge when it comes to derestricting the MT-07 airbox.
I did everything you did in your first post. After putting the bike back together and taking it for a spin, I now have an idle problem. It is idling very high (4000rpm) when stationary. I think I may have missed something when putting the throttle bodies back on. Could this be a vacuum leak? Not sure how to tackle this and taking it to yamaha would mean they would be aware of me opening the airbox up.
Any advice would be of great help. Your posts so far have been the most informative I have found on the net. So thanks for that too.
You seem to be the best person to ask as you have quite a bit of knowledge when it comes to derestricting the MT-07 airbox.
I did everything you did in your first post. After putting the bike back together and taking it for a spin, I now have an idle problem. It is idling very high (4000rpm) when stationary. I think I may have missed something when putting the throttle bodies back on. Could this be a vacuum leak? Not sure how to tackle this and taking it to yamaha would mean they would be aware of me opening the airbox up.
Any advice would be of great help. Your posts so far have been the most informative I have found on the net. So thanks for that too.
FYI - No ECU remap done, and still have throttle restrictor in place
Mods:
Yoshimura exhaust
DNA Air Filter
Opened Airbox to 42mm holes and modified snorkel
Dobeck EJK
Pretty happy with the dyno, knew the bike had more in it form stock and just wanted some confirmation to check AFR. Actually had to lean up the fuel map to get the second line closer to optimal values, so the bike is definitely rich from factory.
Bike sounded glorious on the dyno, don't get to be a bystander with it much so sounds different from that perspective.