YZ125X Yz125 best pipe for grunt

[Burger72]

As the trusty yz125 has been around for years now, what everyone’s thoughts on the best front pipe out there for grunt and overall more power ? Yz125x so it’s already really good but would like to try another front pipe rather than the stocker....

[SmokinJoe]

Definitely not the pro circuit it's all top end. 

[rpt50]

Way back in the hey day of smokers, magazines used to do pipe shootout comparisons.  Maybe you could find one that is still relevant, since the YZ motor has been the same for so long.  

I have a couple of the regular YZs with stock and PC pipes.  The main thing I notice is a little better over rev with the PC pipe. 

[Turboloader]

Stock is best for grunt. A-lot of folks mis-understand the purpose of pipes, gearing, power-valve set up, tires etc. They are actually are ment for different types of tracks. You change up your stuff for the long straights, and speedy tracks, you want to go high revving for your scoot, a torque pipe would be useless. If the track is tight and twisty, yeup get you a torque pipe, gear it low, and have a blast. It all depends on the track...?

[shrubitup]

15 hours ago, Burger72 said:

As the trusty yz125 has been around for years now, what everyone’s thoughts on the best front pipe out there for grunt and overall more power ? Yz125x so it’s already really good but would like to try another front pipe rather than the stocker....

Fatty is what @SDR_rider found to work best.

[shredmasterz]

For 2 strokes, a longer head pipe will make more low end power at the expense of peak power and conversely a shorter head pipe tends to make higher peak power and reduces low-end.   If you are handy with metal work you can extend your head pipe length to move your pipes power band towards the lower rpm range.

[Singletrack_rider]

What I found on my X was the FMF fatty helped with the mid-range and top power. Below lets say 6000rpm there was no difference either way. Stock or FMF felt about the same off idle. Pipes have little to no effect at low rpm. I added an inch to a CR125 pipe once. Made zero difference in the low rpm range.

If you want more grunt put the regular YZ head on. That made the biggest difference in power in the lower RPM range.

[Turboloader]

Redundancy, Deja-vu...?

[Rosehill Ryder]

6 hours ago, shrubitup said:

Fatty is what @SDR_rider found to work best.

We've had two 125's and they both got used for Woods only and the Fatty helped all the way through the power curve !

[mlatour]

Since the OP is located in the UK, 

one pipe manufacturer that is rarely mentioned but usually gets very good reviews is HGS,

lesser known to north american riders but very popular in Europe.

They offer both a 'torque' and 'rev' pipe for the YZ125.

 

From past discussions, DEP pipes also make a 'torque' version.

Edited March 23, 2020 by mlatour