06 YZ144 Pipe and Jetting Recommendation

[mxracin]

I just got my sons EG YZ144 with mobetter porting back together. Does anyone have any recommendations for exhaust and a good starting point for jetting?

 

[robwbright]

As to the pipe, I can't contribute anything other than that he said a Bills Pipe would work fine on my RM.

As to jetting, Eric told me that the combination of 144 and mo betta actually modifies the bike in such a way that the jetting would probably be close to what it was before the 144. I found this to be true - I had to play with the needle clip, but that was about it.

Your results may vary . . . ;)

 

[MXP1MP]

I just had mine done also but I had mine ported for mid/top and race gas only head mod only had it back bout 2 weeks now. I'm still playing with jetting but I had to richen the main from the stock 410 to a 450 and went up two on the pilot to a 50 but i think i might go back down one to a 45. I left the needle stock in the middle clip position it runs good with these settings.

edit: I forgot to mention my bike was stock the first time I ran it and I got a V3 since then. Compared to last weekend when it was stock other than the jetting changes and the 144 stuff I took it out on a trail ride to break it in. It's was in the 40's out but I wasn't getting on the pipe as much. The plug was black but not oily residue black so it wasn't totally fouling out just alittle rich plus I had the gas mixed at like 24:1 but it's now 32:1.

I swapped out the stock reed block for a Vforce V3 and the bike runs better with it I can see where the stock reed block stuffer is alittle restrictive. Well I took it out to a local sand track new Mt St helens (yes that one) so it's a sandy/ash.

Well I did a few plug reads and the first one on low speed was still showing alittle black but when I did a 3rd gear on the pipe/main it came out tan! I don't want to go any leaner I sized it the first time I had it on stock jetting. I was running trick 114 at 40:1 and only had maybe 40 mins on it when that happened. Thankfully Eric was awesome about it and fixed for no charge.

 

[steve_o78]

Mxpimp,
I have been thinking about getting an 06 yz 125 and getting the 144 kit for it and just wanted to know how sweet it is :) . also with the mid top porting did you notice any loss at the mid bottom (not bogging it)? think it could hang with a 250f, I know that it is mostly rider but want to know if it is capable, also I've heard they handle awesome and feel really light. Just want to get an idea. Thanks

 

[MXP1MP]

No cause the bigger piston negates any trade off from the top/mid porting. Even with the slightly rich jetting I got in it right now it totally snaps torque's way better off the bottom over the 125 setup much more 200 like. It's not loop out crazy like a 250 but long as your in the right gear or close to it. So far I'm shifting less cause it's easier to torque threw a gear higher then normal. The stock gearing feels alittle off now like I need to drop two on the rear or do something like a 14/50 gearing. It got alittle more snap/responce out ot if when I installed the Vforce V3. Last weekend I rode it out on a sand track and it pulled on 250F's all day! It was do able as a 125 the 144 made it seem easier like my 250 I'm scared I won't want to ride my '06 yz 250 anymore now. This '06 yz 144 is awesome a good few of my friends who have new 125's are super jealous. They can say when they are behind me they can hear how i'm not as high in the rpm nor working as hard as they are and going just as fast. I've only ridden it a few times and last weekend was a really good test cause the track was rough and had deep sand sections and was high speed and techincal. I got in before the price increase and so far best $475 I've spent on it. I know so people say get the suspenion done but I have no complaints with the stock setup for '06 for me it's like damn near perfect for everything I can throw out at it. I have to make mine yellow n black to match my 50 th anniversy yammie gear.

 

[robwbright]

I got in before the price increase and so far best $475 I've spent on it. I know so people say get the suspenion done but I have no complaints with the stock setup for '06 for me it's like damn near perfect for everything I can throw out at it. I have to make mine yellow n black to match my 50 th anniversy yammie gear.

Me too! Mine was $450 . . .

I bought the Bike Setup Secrets video for $5 off that auction site - hosted by Greg Albertyn. Interestingly, he stated that if he were a recreational racer and had $1000 to spend on a 125, he'd put all of the money into the motor because the suspension is usually pretty good on 125s and the motor makes all the difference.

He stated that if he had the same $1000 to spend on a 250, he would put it all in the suspension. . .