Anybody tried a bigger carb on 99 YZ125?

cr-man

Lifetime Sponsor
Joined
Nov 6, 1999
Messages
339
Likes
0
#1
I'm intersted to know if anybody's tried a bigger carb on a 99 or 00 YZ125 and how they liked it?
 
Joined
May 16, 2001
Messages
32
Likes
0
#2
I have heard a few of our local pro's will bore them out. Around the same as the 01 YZ125, from 36 to 38mm.
 
Joined
Apr 18, 2001
Messages
139
Likes
0
#3
I have a 97 yz125 w/ a stock 36mm carb. Just 2 nights ago we put a 38mm carb on the bike, once we got the jetting correct the bike ripped! There was a big noticable difference in power! We didnt lose any bottom, yet we gained bottom and top. From my point of view there was no power loss just a big gain. I personally love it! Thats just my take on the bigger carbs. Good luck and let us know what your results are!
 

cr-man

Lifetime Sponsor
Joined
Nov 6, 1999
Messages
339
Likes
0
#4
YZDezertGuy what carb did you use? and about how much did it cost and where did you get it? Thanks for the replies
 
Joined
Apr 18, 2001
Messages
139
Likes
0
#6
CR-MAN... I didnt have to change the airboots at all. Everything matched up perfectly. It was a Mikuni Carb. I actually recieved the carb. when i bought the bike, im not sure where they got it. Im sure if you checked around at your local shops they can get them in or contact Mikuni personally.
 
Joined
Jul 27, 1999
Messages
22,689
Likes
507
Location
Chicago
#7
Joe - Call AJ Wagoneer at Service Honda. He can fix you up with a sweet deal on a TMX 38 if you want to experiment with the bigger carb.
 

EricGorr

Super Power AssClown
Joined
Aug 24, 2000
Messages
708
Likes
1
#9
Hey Joe, the jets from a 2001 YZ125 should be a good baseline because that bike comes with the 38 stock.
 
Joined
Apr 18, 2001
Messages
139
Likes
0
#10
Eric, Rich, maybe you guys can help me on a question i have hear. Just got the new Dirt Rider and was wondering about the 02 yz125 carb. 38mm bored to a 40mm on the intake side? Whats the advantage of this? Is there an advantage to that? Im sure there must be. Also, can a stock carb from a 01 yz125 be brought in and bored to a 40mm on the intake side if the differences cause a dramatic change? Thanks guys!
 

cr-man

Lifetime Sponsor
Joined
Nov 6, 1999
Messages
339
Likes
0
#11
Hey Eric, I got the 38 tmx today from AJ. my question would be the difference in carbs as my bike comes stock with a TMX-x and the carb I bought is a 2001 cr250 carb a TMX they have a different slide shape the TMX-x being half moon shape and it's a little shorter do I have to compensate for this or should I be good to go with the 2001 YZ125 jetting as the base line?
By the way Eric that swain tech coated piston is the bomb!!!! I can't believe how well my pistons holding up!
Thanks, Joe
 

shaggy829

Subscriber
Joined
May 28, 2001
Messages
130
Likes
0
#12
hey guys i run a kiehen 38 pwm (same as a 98 yz 250 carb) on my 00yz 144
it bolts up perfect even uses the stock cable . the performance is the best
yet, more bottom mid and top . I had the stock 36 tmxs bored to 37 but
didn't find it tobe that much better up top . the pwm woke it up everywhere
and it is a breeze to jet .:) :)