PC yz250 pipe talk on pulp

Never tried a stock pipe on my '15 yz250 as I got it used with the PC pipe, but on my '05 yz125, the stock pipe is a real contender compared to the PC RV-spec.

I like to think that Yamaha, who certainly knows acoustics from all their decades producing musical instruments, has a solid understanding of the acoustics needed for an exhaust expansion chamber.

This was my experience as well. Getting squish fixed and playing with the pilot and clip position made all the difference.

Man I'm kinda itchy to pick up another yz250 🤣

This is your confirmation to grab a YZ 250 😆

Did they ever show the dyno chart for this pipe?

Tough to beat the stock pipe. The FMF beats the stocker in the midrange and overrev at the expense of a bit of lowend. 

I loved the PC for MX, but not enough low end for anything else.

Of all the YZ 250's I owned, I tried all the pipes. Best combo I found was the DEP pipe with PC silencer (non-shorty). The HGS pipe was very close to the DEP, but not quite as much overrev.

I grabbed a screenshot of pulp posting the dyno.

I just got this pipe and tested it back to back with the standard one at Hangtown last weekend. It’s def a noticeable difference in power, especially with how long it pulls. 

 I recently got my motor ported by PC, pretty sure I got Mitch himself to do it too because I received a call at 7:15 pm the night before Christmas Eve saying “Mitch doesn’t like your cylinder plating so we’re gonna use a new jug we have here.” First off that checks out with his reputation that’s he’s there working past 7pm two days from Christmas! 

I got to ride that motor with the standard pipe and of course now with the rv pipe. I also have a 24 yz450 that I rode Saturday and Sunday along with the yz250 and I swear to god this yz250 is not giving up anything to my yz450 now. I’ve been pretty disappointed with the power output of my yz250 since switching to it from a Ktm 300. This motor and pipe have completely blown me away now with how much there was inside this motor. My butt dyno thinks it’s damn close to my yz450, so fucking rad!

This is the feedback/info we need! I race an X in harescrambles/GNCC/Enduro. The stock system isn’t bad but if it picks up across the curve  and not just on top with the champ stamp it might be the magic ticket.

It would be nice if they could find a way to fill in the big dip in the power curve on that RV pipe so that it mimicked the profile of the rack pipe.

For what it’s worth I didn’t feel that dip one bit when riding. 

I’m gonna get a lot better feedback this weekend at my home track. Last Saturday’s conditions at Hangtown were gnarly, wasn’t the best time to test two stroke motor items as I was more focused on survival!

bigger main ?

I'm thinking it's more likely a combination of port, PV and ignition timing - it seems like I remember the dip on most HP plots occurred at the PV opening and then regained the positive slope as the pipe and ignition advance came into tune with the now larger exhaust port area.

 The bike builds I've seen that address similar situations are usually looking at those areas. An electronic PV (like the last CRs) would allow more tunabilty/synchronization with the others versus a mechanical PV controlled by spring tension that opens over a narrow RPM range. I'd like to see what it would do with the Hitliss system that is supposed to offer more control over the PV opening/closing range.

I would like to listen to this? Can you please tell me who "they" are? And if possible, the number or time frame this came out? I am eager! 

Thank you in advance

It'll be interesting to hear some real world opinions on this pipe. I just... can't with media guys and test/product shit these days.

I'll also get my hands on one sometime this spring and test it myself. Still got an FMF hanging up and I believe my brother has my old PC pipe. Would be cool to get some back to back to back tests in.

I too would like to see more real world feedback on this exhaust.

Most of the YZ250  “product tests” I see focus on pretty much the same stuff. No one is testing the FCP/WCL engine mounts, Luxon rubber engine mounts, different offset clamps, FCP race cups, or the PC/Ride Eng longer linkage arms. 

It was on the Pulp show with Mitch Payton. He explained that the dip in the curve is necessary to make that power (if I’m remembering correctly).

I just did my first back to back moto today at my home track where I can really tell as I have a million laps here and know my shift points well. I also have some straights that are faster to grab another gear but I can’t always get it when I’m tired. Wow, what a difference this one makes! I’m gonna call PC Monday and recommend they stop selling the old pipe. The new one feels very similar down low, a good improvement in the mid and an unbelievable gain up top. This pipe literally does not sign off. I’m honesty shocked after that moto I just did and shocked that pc would still offer the old pipe. Like I said, I’ve got a couple sections that you really need to grab third on but you can’t always get it, now with this pipe, you legit can just let it eat and it keeps pulling. 

It’s a pretty noticeable difference in the shape of them too, my track is very deep right now so easy to feel the power.

Would love to see a back to back comparison on a stock bike. Maybe the PC engine package makes the most out of the champ pipe. I am just trying to find reasons not to replace my Works pipe with this one 😂

Yea I have the “rv” spec motor package as well so they probably compliment each other. For what it’s worth even with all this motor work, I still think the ktm 300’s are better motors. I rode those from 2017-2025. Both the carb and efi 300’s imo are the best two strokes. I might try an Athena 300 kit on this yz. 

Any chance you remember what your best jetting settings were? I’m juggling between the Mikuni and  kehin and just can’t seem to find that sweet spot.
 sea level

I’m running a 48 pilot and 178 main. I live in Humboldt county and it’s been around 55-65 here, almost always super foggy and muggy here so we def have very dense o2 rich air. Once summer hits I’ll go to a 175 main. I run c12 straight with 927 32:1

FWIW, with the temps being the same, muggy/high humidity would make it run richer than in lower humidity and require leaner jetting.

And the higher summer temps would require leaning over lower winter temps (denser air), so the MJ size drop in summer makes sense. 

Videos finally coming out on this. Just picked up a lightly used 2019 and will probably keep it stock for a bit but looks like I'll be picking one of these up later on

https://www.youtube.com/watch?v=cfum919O7aw

I can’t contribute to the differences between the two specs of the pipes. But I wanted to share a tip for keeping raw pipes looking good and easier to maintain. 

Clean your exhaust up really good and coat it with Cerakote wipes ($15 for 10 wipes on Amazon) and it keeps the rust off. The only place I have to touch up is the initial curved section. Very minimal scuffing in that spot then reapply and it looks perfect again. The main portion of the exhaust doesn’t get hot enough to do anything to the coating. It does give a little shine to the exhaust so if you want it to look dull don’t do the Cerakote wipes. 

Before and after of the minimal scuffing required to maintain:

will be a lot of these pipe running up the hills of Gen Helen this weekend

Man I wish they had it for my YZ125

Yup, if not the stock pipe, this...