Best Pipe Setup - 06' YZ125

[OverheatedR]

Just wondering what you guys are running out there and what pipe(s) I should get for my new 125. I was thinking either a Pro Circuit/R304 silencer or an FMF Factory Fatty/Shorty silencer. The bike is all stock and if the bike is missing one thing, that's throttle response, because the bike revvs to the moon! Would like to get better throttle response/ lowend power while keeping the same revv out if possible in the pipe. Bike has stock jetting with slight bog if I crack the throttle too hard, so I want to get rid of that bog. Main mod's I'm looking into are VForce reed cage setup and pipe/silencer combo for now. Tell me what you think!!

 

[NacNac250F]

Biggest difference would be to get the cylinder ported. That was my money best spent. It was cheaper than a pipe/scilencer and reeds. My friend with the same exact bike as me (an 05' YZ125 which is pretty much esactly the same as an 06') tryed PC pipe and scilencer and v-force reeds and also tryed and FMF system as well with the v-force reeds and barely made a difference over stock. My bike is ported with everything else stock and it blew his away and I spent half the money. give www.tech-care.com a call they did my porting and it works awesome; completely reliable and great throttle response.

 

[OverheatedR]

Yeah, I was planning on getting the engine ported soon and/or a EG 144cc bigbore, but right now I need to get some more power downlow. By the way, did your bike or his have a bog at all in the lowend when it was all stock?? I'm starting to think the bike might be jetted a bit fat stock, but I doubt it. When it's warm, the bog isnt so bad, but it definitely is still there unless I really ease the throttle out a bit every so often when Im in turns or what not.

BTW What pipe did your friend like better, the PC or FMF overall, and how did the two perform across the powerband?? Thanks for the help and info.

 

[Pete Payne]

Track and dyno testing have shown me that the FMF factory Fatty is the best pipe for stock cyl , ported stock bore cyl or 144 kit . This is between the PC , FMF fatty and FMF factory fatty.
Just my 2 cents worth.

 

[OverheatedR]

Ok, thanks alot Pete, than I guess FMF it is. You say this is between the PC and Fatty. Is there another pipe out there im missing out on?? Bill's, Doma, Dep, etc., or is the FMF Fatty just the best pipe for the YZ125 period? Thanks again...

 

[ruffrydaz127]

woah whats up buddy, this is big-ped00. i have a pc on my kx ripps dam well. ever been to the rockyhill track? www.ctmotocross.com .if ur ever heading out to this track tell me and well tear it up.

 

[AssistSuper]

Y I'm starting to think the bike might be jetted a bit fat stock, but I doubt it. When it's warm, the bog isnt so bad, but it definitely is still there unless I really ease the throttle out a bit every so often when Im in turns or what not.

I'm not the best with jetting, but it sounds like your bike is running a little lean on the pilot jet, perhaps the needle as well.

When the temps drop, the jetting leans and when it warms it should richen due to the air density. Cold air is more dense. Which would explain the bike running better when it's warmer outside.

Try putting going up a size on your pilot, it could make a huge difference.

I have been running a 42 pilot for temps around 60ish, and went down to a 40 this past weekend in anticipation of warmer weather. It was a mistake, as all I did was bog all over the place down low.

I may be incorrect with the jetting, so someone please correct me if I goofed it up.

 

[MXP1MP]

I ended up jetting mine alittle leaner over stock actually one leaner on the pilot to a 37.5 and the clip pos to #2 mine was running alittle rich stock. Def get the Vforce for it that helped get ride of that bog it sometimes get. The stock reed block looks alittle more restrictive than it should be more like yamaha was alittle conservative when it came to the stuffer piece.

I just put the factory fatty on mine with the shorty ran the stocker for a good while since aug and the FMF is not a oem copy different bends and cone shapes. It really helped out my 144 the stocker felt like it was choking it off up top only minus is the bigger cones blocks oil filler hole access some. Glad I got it and if you think it's fun stock should try my EG 144 :) you won't ride it stock again.

 

[OverheatedR]

I ended up jetting mine alittle leaner over stock actually one leaner on the pilot to a 37.5 and the clip pos to #2 mine was running alittle rich stock. Def get the Vforce for it that helped get ride of that bog it sometimes get. The stock reed block looks alittle more restrictive than it should be more like yamaha was alittle conservative when it came to the stuffer piece.

I just put the factory fatty on mine with the shorty ran the stocker for a good while since aug and the FMF is not a oem copy different bends and cone shapes. It really helped out my 144 the stocker felt like it was choking it off up top only minus is the bigger cones blocks oil filler hole access some. Glad I got it and if you think it's fun stock should try my EG 144 :) you won't ride it stock again.

Thanks alot man and i'll try it when leaned out a bit, because my plug just can't become the right color on the stock jetting with 32:1 ratio. I plan on getting the factory fatty/shorty and a vforce. I heard alot of good things about the EG 144cc, but am afriad it will kill the revvs. I'm sure you know how the stock YZinger 125 revvs like no other, and I hate to get rid of that and have to reside to constant short shifting. But any advantages over those damn 250f's I'll take!! :D

 

[OverheatedR]

woah whats up buddy, this is big-ped00. i have a pc on my kx ripps dam well. ever been to the rockyhill track? www.ctmotocross.com .if ur ever heading out to this track tell me and well tear it up.

Hey bro, yeah I've been to Rocky Hill once only to watch. Can't wait to get my bike up there and tear it up soon. How do you like it, from what it looks is a great track! You hit up that 80ft. double?? haha I'll deff talk to you on aim if I go out there. I'm currrently waiting for my acceptance at Milford MX club as well, you should try to join too.

 

[MXP1MP]

Well I felt like I had lost a tinybit of the over rev when I went to the 144 but I got some of that back with the fatty installed now trust me it doesn't loose that much over rev it's still rides very much like it did as the 125 and besides you can ride it lower in the power band more effectively and do things a gear higher. i'm going to start playing around with gearing it now I know that will give it the pull back in the lower gears. Oh yea I pulled a guy on a yz250F on this very tight inside line little slip of the clutch in 3rd gear! and pulled him! guy did a double take as I went by! I had my 144 ported for more mid/top believe me it's like your stocker on steriods. So what it flattens out on top alittle more noticeable but that high up so did the stocker it's not like over rev is that usable anyways typically you should have shifted by then so you can still ride it like it was stock still plenty of rev there. I think I notice the flatness more cause it pulls so much better threw the entire range now. 14/50 gear is what i'm trying next it might give back so of that pull in each gear. stock ratio is 3:69 14/50 ratio 3:57 it's got the torque to pull it now.

 

[ruffrydaz127]

na not clearing the 80 footer yet lol, ill have to check out the milford track sometime if i can get a ride there. you interested in meeting me at the rocky hill track during april vacation? well ill try to catch you on aim tomorow peace.

 

[Pete Payne]

Overheated ,
I would use the FMF "Factory Fatty" , not the "Fatty" . These are 2 different pipes .

 

[OverheatedR]

Yes, Pete I would only run raw pipes on 2-strokes if available. The "Factory" Fatty it is. Is the Titanium2 silencer worth it in weight loss or any performance over the Shorty besides the expensive price tag for a titanium end cap?? lol Just curious...

 

[MXP1MP]

Nope it's not worth it, all it does is just make your wallet lighter :) I just got the normal shorty.

 

[Pete Payne]

MXP1MP got it right . ---Lighter wallet.