AZRickD's RB-Design Carb Mod Report
 

Last summer I had Ron do a squish band mod. Major, major improvement.

This spring I decided to have him do a carb mod. I was most concerned with what it would do to my carb jetting performance at altitude. Phoenix-area riding is 2,000+ feet and 95F at sun-up this time of year. Flagstaff is 7K to 9K feet at 80-90F in the afternoon.

Last year I would have to lean out my MJ to 162 to cure the bike not wanting to reach the upper revs in Flagstaff. The PJ was around 38. This year in Flagstaff (last couple of weekends), I have had the MJ at 168 and the pilot at 40. It has been working very well. Just a touch of hiccup when I'm reaching the upper elevations that our riding in Flagstaff has to offer. The pilot might be just a touch rich.

I washed the bike and warmed it up tonight with a tour of the neighborhood lofting the wheel over imaginary obstacles. It ripped. I may have to do a plug chop to see if I can run similar jetting down here (and/or just adjust the needle clip).

What have others experienced with the RB carb mod in this regard?

I think I was one of the first to have this done. I recall provided a lot of input to Ron after I got it back. It was great. I was having all sorts of issues getting the carb sorted out. I already had the LTR kit and things were pretty good fro the most part, except off idle.

Ron's mods cleared that up and the bike pulls harder on the top end.

All in all, I was very happy with the mod.

Just rode for a real ride the first time out with my RB Designs modded carb- holy crap what a difference, bike truly rips now, and it idles too LoL

My 07 ec300 has the RB head and carb mods and rips on top end. Last Friday I drag raced a friend who has a nearly new yz250 that is tuned really crisp. We ran side by side through the first 5 gears. My gasser has 50 more CCs but it also has the heavy enduro ignition, 4 year old reeds, needs a jetting change , and was pulling at least 50 more pounds down the road. We topped out 5th gear side by side then I walked away from him in 6th. RB does good work.
p.s. My gas mileage went up 5-10% after the head mod.

Take it easy on that bike now!! LOL