Does anyone have any experience with these exhausts? http://www.ebay.com/itm/Exhaust-Modified-Scooter-Pipe-Slip-On-System-For-Yamaha-FZ-07-MT-07-XSR700-14-17-/272746082827?fits=Make%3AYamaha%7CModel%3AFZ07&hash=item3f80eef20b:g:zhcAAOSw1BlZWdG0&vxp=mtr
 
And how about combining them with these mufflers? http://www.ebay.com/itm/Universal-Exhaust-Pipe-Dual-outlet-Tail-Pipe-For-Motorcycle-Exhaust-System-/122599658087?epid=12003105090&hash=item1c8b825267:g:md0AAOSwEUVZaG9Q&vxp=mtr
 
Or will it be too loud? I have ordered a lot of things out of China and never had a bad experience but it's still a huge risk (in this case $250). Or will I be better off with an M4 Slip-on?

[div]The M4 slip on is nice and I like the pipe with the snail but if you wanted to save even more money this exhaust can is cheaper and probably just as loud as an M4. I can't vouch for how well it's made or anything so buyer beware! GL!
 
 
http://www.ebay.com/itm/Exhaust-Muffler-End-Silencer-for-Yamaha-MT-01-FJR1300-XJR1300-FZ-07-/262879944109?hash=item3d34dd9dad:g:w7sAAOSwXYtYuFDT&vxp=mtr
 
 
Give us an update when you've bought something. Pics, video if at all possible. 
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Some of the welds on that system look poor - and that's on the pics the vendor chooses to put up. I wouldn't expect any better for that low price.
 
An M4 slip on is better choice in my opinion.
 
Let us know how you go

You might want to be a bit careful with this one. I tried to get into the other headings for the store and they are blank pages.

I remembered reading about an exhaust from China a while back. See if this helps at all... https://fz07.org/thread/8519/new-exhaust

Or if you wanted something a little more "name brand" you could look into Black widow exhausts. They run a little over $100 more than what you are looking at spending right now and they are a name brand exhaust. I like the ones they have that look similar to the Delkevic exhausts and they are slightly cheaper than Delkevic. Can't say how they run performance wise I have no experience with them but I have looked up just about all the exhaust options for this bike just to see what's out there.
 
http://www.ebay.com/itm/MT-07-FZ-07-Tracer-700-Low-De-cat-Exhaust-System-Stainless-Round-Silencer-200SS-/142046921450?epid=621002519&hash=item2112a802ea:g:mcwAAOSw-0xYOB~z&vxp=mtr
 
 

Do you always have to flash your ECU when you put a slip on ? It looks like it cost about $350 to flash an ECU so it is a big extra to the price of the slip on or full exhaust.

6 hours ago, laurent said:

Do you always have to flash your ECU when you put a slip on ? It looks like it cost about $350 to flash an ECU so it is a big extra to the price of the slip on or full exhaust.

Yes. Anytime you alter the air flow going into or out of an engine, fueling needs to be compensated. These bikes already run lean from the factory for emissions purposes, adding more airflow will only make that mixture leaner. I run a PCV with autotune set to 13.2AFR and man what a difference it made. Huge gains on the butt dyno. Pulls so much harder running 13.2AFR.

Ok, now i know. Thank you very much for the info. 

Unless the exhaust makes the AFR beyond the scope of the  adaptation range of the ecu/O2 sensor the bike should be able to compensate and stick to it's tables. ie it should run the same lean. It may take a little while ( I haven't seen anything on how fast the system adapts).

If you are going to the trouble of putting on another exhaust makes more sense to get the ecu reflashed ( my preference) or PCV or equivalent. As CarGuy7a said, these things run lean stock.

The stock efi system does not have a capability to adapt to air:fuel ratio changes outside of closed loop running.

 

When 'eco' mode is shown on the dash the fuel injection system is running in closed loop mode, altering the fuel inputs based on the the narrow band lambda sensor in the exhaust.

 

The fuel (and timing) tables can be altered by an ecu flash, pcv etc. There are some efi tuning devices on the market that change injection in real time (i.e. auto tune) at all throttle positions and intake air pressures as you ride, these utilise a (more expensive) wide band lambda sensor.