Best 125 2 Stroke Exhaust

I do remember on all my yz 125s I ran a stock pipe and a pc shorty silencer.. katin also ran that combo quite often..
 
Best combo for the tracks around here ( long and fast ) is a Pro Circuit pipe, with a factory 304 silencer... Best combo hands down.. FMFs are junk and dent very easily.. Go with PC you wont be sorry
 
I ride Apple Cabin, Smith Rd, OIR, Beans, Amherst, tracks like that. So PC is the best you think? DEP is out of the question because i dont know many people who run em. Right now I have a FMF SST pipe, with a Titanium 2 silencer. My dad has the same year bike, and he is taking that system, and I have the choice to buy any system of my own myself, so thats why Im asking.
 
I have run both FMF and PC multiple times on my YZ 125's since 05.

The FMF fatty with the shorty silencer has better all around power and the pipes are made with a little thicker gauge metal and hold up better. The welds have more meat to them as well. The jetting changes are usually minimal if even required. This is my preferred combo.

The PC with the 304 shorty makes a little better top end power but doesnt provide the nice mid range of the FMF. The PC pipes are lighter gauge metal and dents and dings are far more common. I have had 3 of the 304 silencers break the welds that hold the mounting tab on .... silencer falls off while you are riding. My last one I had the tab welded and metal added to reinforce it. Jetting is VERY lean on top. My 05 YZ almost roached a piston in one race the first time I ran it. I also knew a guy who did loose a top end on an 05 YZ due to this problem. I think I went up 4 sizes on the main. If you can ride in the upper range of the power ALL the time it may be a better set up. This is my current set up only because it came on the bike I have right now and Im too cheap to replace it with the FMF stuff.

Personally I prefer the FMF for its mid range power, easy jetting and durability. Of course that is just my opinion from my experiences.

Wow....I hope I didnt sound to Rocket Robinesque....lol
 
Put your money in the best suspension you can afford...you'll go way faster with it than with any engine mod...

Just my 2 cents
 
I have had procircuit and fmf on my bikes.but i think DOMA pipe and silencer make the best spread of power for my bike.
 
Dang, couple days late for this question....just got the PC Works pipe and R304 shorty combo....haven't rode it yet but it sounds sweet as hell....thought I'd get this done and out of the way before working towards a 144 kit in the next couple months
 
What's up bud! I was looking for ya at the 'Cabin the night of the benefit. I stopped by your setup, but you must have been out riding. I'm assuming that was your '84 RM I saw? Boy is that a sweet one!!!

Anyway-- the best pipe would depend on what you're looking to accomplish. Since it's a 125 we're talking about, I'm assuming a broad power spread is what you're looking for. I came across some dyno tests by accident (It's a long story, but I was looking for the best, and easiest to ride power spread from a KX65. I've got one that I'm setting up for mini-supermoto). A guy was doing independent testing WITH a dyno on a bunch of two stroke MXers. What he found was that the FMF pipes made the best peak power, but were slightly down through the low and mid. The Pro Circuit Works pipes had slightly less peak power, but consistently made the most linear gains, and would most likely make for the easiest to ride power curves.

I know you're plenty knowlegeable, but I hope this helps. --L*64
 
PC platinum 2 is the same pipe as the factory, just has heavier gauge steel. So they fixed that problem with the plat2

Parked mine on a log and didn't dent. Luckily. Haven't got many dings in her either. I've heard the factory pipes just bend easy.
 
LuckyStar64 said:
A guy was doing independent testing WITH a dyno on a bunch of two stroke MXers. What he found was that the FMF pipes made the best peak power, but were slightly down through the low and mid. The Pro Circuit Works pipes had slightly less peak power, but consistently made the most linear gains, and would most likely make for the easiest to ride power curves.
Click to expand...

Dynos are a great tool but rider input is far more valuable. Have you noticed in the bike shoot outs ( MXA , Dirt bike ect) they have dyno charts for each bike. Rarely is it the bike with the best dyno curve that the riders pick for the best rideable power on the track. I only posted what I experienced using both pipes on the same bike.
 
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