Has anybody had the TMXX carb mod done by RB Designs? Here is the link. What do you think?
http://www.rb-designs.com/mikuni-tmxx-carb.htm
I had my 05 YZ 125 carb mod performed by RB, had the full tilt job. I race offroad cross country hare scramble and enduro with my 125. I was not really happy with the OEM set up, I spoke to Ron several times about the mod and I went for it. No regrets!
He also replaced a fuel block gasket (I think that is what he called it) when he was in there performing the mod.
The mod helped with tuning, air screw is very handy to make small adjustments as well. Ron suggested a needle, to replace my OEM.
Overall the throttle response is great, very crisp and really easy to jet now. I swap out slow jet depending on temp and altitude and a little fine tuning with the air screw and that is all.
I keep really good notes on my jetting and race locations, so I have already taken out the guess work.
Hope this helps.
Helps....yes and no. At least somebody with a yz125 has experience with it. However, we have never had issues with tuning and jetting and throttle response, that some guys seem to have. Not sure if it's because of geographical location or what. More than anything, I wanted to see if it improved POWER. When we did a same day comparison of the stock exhaust with the FMF, my son said the FMF started pulling earlier and pulled longer than the stock exhaust. So I guess I'm looking for some a more defined difference like that. It's possible that I'm searching for something that does not exist, but who knows. Stock throttle response on both his 2007 and 2012 is excellent. He just hammers it and it flies. Was hoping to find something a little more than stock, but without having to go to porting or big bore. Thanks for the info...
I am located in California, Central Valley area near Stockton, Ca. I am 51 years young and race in the District 36 Cross Country series as a "B" Super Senior. I am 5'11 and weigh about 190 in street clothes. Yes, a little big for a 125, but it hauls the mail with my butt. Our race locations very from sea level to sometimes 4000ft elevation and temps are all over the board, in Jan when our spring series starts temps can be on the high 30's or 40's to 75+ plus, depending on your start time. So, there can be some jetting issues. The majority of the racers in my class are on 250 smokers, 350's and 450's. I can hang with the bigger bikes at just about every venue we race at, except in the more wide open high speed stuff. The 125 will pull hole shots against the bigger bike in my class.
I should have provide a little more info in my first post about my bike. It has a Al Posey motor
http://www.poseyracingengines.com/ very mild porting / polish, squish mod head, to run on 50/50 race gas and pump. V Force Reeds with a OEM pipe, Leo Vince shorty with spark arrestor, GYTR clutch package, 13/50 gearing, skid plate, 3.2 gallon tank and Nor.Cal Motorsports suspension work for offroad.
My main reason for the mod carb was, I wanted a little more off the bottom.....yea, it's a 125, I get that how much "grunt" can you get out of a 125? I was looking to smoothen out the "hit", kinda take away the light switch effect, provide a little more grunt so I could lug it down when needed and still be able to have that super fun 125 effect. When I spoke to Ron @ RB I asked for details on the mod, what should I expect when properly jetted? He stated that the divider plate would help with some bottom, the boring to 39mm just finishes off the complete package and will make tuning much more simple.
My buddy had this same mod performed on his Husky 2011, WR125, same carb, everything. So we swapped carb for a race and I noticed a nice improvement down low, the mid hit was much smoother and it still rev'ed to the moon when I needed it to. So, I sent off my carb.
As for power, no dyno runs, just pure "seat in the pants feel" it feels stronger with the RB carb, every where, from the bottom to the top. I am happy with the product and the money spent was worth it to me.
I am using my 125 for cross country, hare scrambles and other forms of offroad racing and what I was looking for with regards to the mod carb has meet my expectations.
Which FMF pipe did you try? Have you tried any DEP pipes?
Thanks
