Messages

1

Technical / Carb Mod question

« on: November 14, 2013, 06:08:57 PM »

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...

2

Technical / Carb Mod question

« on: November 12, 2013, 12:14:06 AM »

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

3

Technical / porting and head mod???

« on: November 06, 2013, 11:26:23 PM »

Was originally planning to have my son's 2012 yz125 ported and head modded by KB5 in PA.  Running into $$$ issues during the upcoming offseason and might not have enough to do the porting.  So here is the big question.  Does a head mod provide enough of a USABLE difference to make it worth doing by itself.  Bike is stock with the exception of the FMF Fatty/Shorty.  Want to keep using Sunoco 93 pump gas.  Suspension has already been fine tuned, does not like any aftermarket reed systems and he rides it like a boss.  Races mx in the mid-atlantic states and is upper B class rider.