Question on Porting my yz125

Yz250JdT250

Member
Apr 26, 2004
142
0
Right now my 1998 yz125 has a full season on the top end, its taken in water due to being half underwater a few times, over the season. It will runs pretty strong but i am planning a rebuild soon. I was wondering if, out of these three choices of Eric Gorr's services,

"Porting 125cc $185, 250-500s: $200
Eric offers three types of power bands for big bikes:
1) More Low-Mid This powerband is ideal for hare scrambles, trail riding, and for intermediate racers looking for quicker throttle response and better starts.
2) More Mid-Top This powerband is intended for use by experts riding small bore bikes like minis and 125cc. You must use this porting in conjunction with an aftermarket pipe and carb. Expect a slight loss of low end for a big gain in over-rev.
3) Mo-Better Everywhere This powerband is especially designed for 250 and 500cc bikes. Most of these bikes hit too hard in the mid-range and are flat down low and on top. This powerband starts pulling sooner as you crack the throttle. The mid-range is a smoother transition without the violent hit that spins the wheel, and it pulls longer on top. No need to spend a fortune on aftermarket bolt-on parts. This porting powerband stands alone! "

, if you would recommend the third choice for an all around power increase on it. I am having trouble deciding which one because it is just a 125 so where the porting doesn't favor the powerband it will be probably be too weak. So I'm leaning towards the third choice and i would like to know what you guys think on this.

I like to do all around riding, MX tracks and also rippin up the trails and sand pits. :cool:
 

ZeCatfish

Member
Mar 25, 2005
60
0
sounds like you need a big bore kit, more power all across the board. Maybe a 144cc then go whip up on the 4t's.
 

robwbright

Member
Apr 8, 2005
2,283
0
From what I understand, low mid is pointless on a 125. Get mo betta if you're a novice/intermediate and mid top if you're a fast guy who overrevs a lot. The mo betta is easier to ride.

A 144 overbore kit with porting does wonders. Imagine a 15-20% power increase everywhere. :laugh:
 

Yz250JdT250

Member
Apr 26, 2004
142
0
yeah i would really like to make it a 144 but i dont have the money to rebuild the crankcase also. I think im just going to replace the piston and put v force 3 reeds on it and then sell it and upgrade after the winter.
 

ryan callies

Member
Oct 17, 2002
12
0
Just let Eric know your riding style! If you find your self wide open most of the time have it set up for more over rev! And if you need more bottom and top end power get Eric's 144 Kit and porting ,They fly !! Have a good day ,Ryan Callies Finish Line Engines
 

Yz250JdT250

Member
Apr 26, 2004
142
0
I would love to do that but i dont have the money becuase that would almost definately require a complete engine rebuild due to the crank bearings and trans being worn out. I am just going to put a fresh top end on and reeds
 

Yz250JdT250

Member
Apr 26, 2004
142
0
Then i will upgrade to a newer yz125 with the alum frame and everything. But does that big bore 144 kit require that you get a new cylinder or is it just the sleeve?
 

ryan callies

Member
Oct 17, 2002
12
0
You can have your cylinder bored and re plated. Getting this done by Eric Gorr is the best way to go because you can get porting and head mods done at the same time. Your crank cases will also have to be machined . Good luck and have a good day! Ryan Callies Finish Line Engines
 
Cookies are required to use this site. You must accept them to continue using the site. Learn more…