This shootout was taken from dirtrider.... maybe this will keep the whole what pipe should i get for my yz125 in this situation.. or is FMF better then PRO-CIRCUIT BILL'S PIPE Bill's pipe ($198.50): Bill's offers its exhaust in two finishes: standard bare metal or nickel-plated. Silencer ($98.75): Aluminum canisters are standard with the Bill's silencer, while the end-caps and inlet pipe are plated mild steel. DEP DEP exhausts originate from Europe and are bare steel with mild-steel silencers in aluminum canisters. The exhaust runs $199.95, the silencer $99.95. DOMA Exhaust ($182 for 125s; $210 for 250s): Doma pipes are available plated for an additional charge of $20. Doma silencer ($88 for 125s; $99 for 250s): Stainless end-caps as well as the polished-aluminum canister are standard on the Doma silencer. FMF Right from the start, FMF earned extra points for equipping each of its exhausts with O-rings in the exhaust flange right out of the box. During our testing, we found little or no performance differences between the Shorty silencer and the Titanium II. Although FMF offers a standard-length PowerCore II silencer, we were only presented with the Shorty and Titanium for this test. Factory Fatty ($229.99-$249.99): Similar in design to the Fatty, the Factory is constructed from thinner-gauge material, is precision assembled with hand-pounded welds and remains unplated for that factory look. Fatty ($179.99-$199.99): The Fatty is FMF's standard-issue pipe; it is only available with a plated finish. Gnarly ($179.99-$199.99): The Gnarly is constructed from 18-gauge material (thicker compared to the Fatty) and aimed at off-road riders or those seeking more bottom power and torque. The Gnarly comes nickel-plated and is only available for 250cc models. Rev ($179.99-$199.99): FMF targets the Rev for 125 riders looking for more top-end and overrev. SST ($229.99-$249.99): This unit, which features a special machined stinger section, claims to offer the broadest power delivery of any system in the line. Shorty silencer ($99.99): Unit comes with an aluminum canister and stainless inlet pipe and end-cap. Titanium II silencer ($149.99): FMF's Titanium silencer is built with a titanium inlet pipe and end-cap with an anodized-aluminum canister. PRO CIRCUIT Works/Platinum ($198.50): One design available in two styles, the pipe comes unplated (the Works) or plated (the Platinum). PC exhausts are always very well built with precision welding and craftsmanship. Factory Sound silencer ($112.50): PC's silencers house a round aluminum canister with stainless inlet pipes and end-caps. SRS Exhaust ($200 for 125s; $220 for 250s): SRS is very heavy into building pistons, but the company also offers a limited number of very well-built exhausts. The SRS system wears a bare-metal finish. Carbon-fiber silencer ($140 for 125s; $160 for 250s): These silencers are by far the trickest-looking in the test. The carbon-fiber canister with aluminum end-caps and stainless inlet pipe and bracket are standard on the SRS. Baseline: Stock, the YZ125 is a barn burner with some of the best power characteristics of any 125 ever produced. The power comes on early and runs all the way through to the top. More of what it already delivers is the target for the '03 YZ125. Bill's pipe and silencer Fit: A / Overall Rating: B Comments: Bill's starts off by building more bottom and broadening the already-potent midrange. On top it is about the same as stock. The Bill's delivers moderate gains but enough to consider it better than stock. DEP pipe and silencer Fit: B / Overall Rating: B+ Comments: Other than the fact the kickstarter hits the pipe, the DEP is a great overall addition to a YZ125. It outdoes stock down low, pulls longer in the mid and still wants to rev out on top. Although it wasn't our number one choice, it placed right there on the podium with several others. Doma pipe and silencer Fit: B / Overall Rating: B Comments: The brackets on the exhaust and the silencer were slightly off, and it took a few extra minutes to get the system hooked up. The Doma is very similar to stock with about the same bottom, slightly wider mid and a little more overrev. This is a great replacement system that still adds some performance to the YZ125. FMF Factory Fatty with Shorty silencer Fit: A / Overall Rating: A Comments: The Factory, like most of them, parallels the standard Fatty. Throttle response appeared a little crisper but didn't translate on the track. If you fancy the Fatty, you will adore the Factory Fatty. FMF Fatty with Shorty silencer Fit: A / Overall Rating: A Comments: The Fatty produces a crisp throttle along the way to its award-winning enhanced mid. Up top the power keeps building and wants to rev further than stock and most of the other systems available. One of our two pro test riders marked this system as his favorite. FMF Rev with PowerCore II silencer Fit: A / Overall Rating: B+ Comments: The Rev runs a little snappier compared to stock and supplied more mid along with a longer pull up top. It does rev further than stock, but we couldn't say it screams further than some of the competition. Overall it's healthier than stock. FMF SST with Shorty silencer Fit: A / Overall Rating: B Comments: The SST tenders a broad power delivery but not quite as snappy or responsive when matched up to other leading units. The SST pulls stronger in the mid and on top over stock and seems best-suited for fast tracks. Pro Circuit Works with Factory Sound silencer Fit: A / Overall Rating: A Comments: Picked as the head honcho by one tester, the PC comes to life from the first blip of the throttle. Bottom is superior overall and pulls harder while exiting corners. As the revs start to climb, it keeps pulling until screaming its brains out way up top.