RB Designs-must do/

[gasgasman]

Ever since I got my 2011 250 Six Days bike, I've been fighting with the jetting.
Tried the JD kit, it was close but not suited to my riding style.

I have the Keihin 38mm Air Striker II carb.

I had some down time from riding so I decide to have my head modified to reduce the squish and have the full carb mods done.
I've had RB designs machine work done on my previous bikes, so it was a no brainer.

Finally got to ride the bike with the head/carb mod this past weekend.
AMAZING!!!!!
I did not have to change any jets, just some minor fine tuning with the air screw. (sea level, 98F)

The roll on throttle response pulls like a freight train. It was totally lacking before.
I like to roll the throttle on at the apex of the turns, the bike just pulls away cleanly. Before, the power would not start building until the throttle was 1/2 way open.
I even found myself riding a gear higher. If I got sloppy and let the revs drop, a quick blip of the throttle and I'm back up to speed.
The JD jet kit NEVER ran this good.

My compression jumped up 15psi after the head mod. I'm pleased with that.
The bike would ping before-now it doesn't.

For the price, I would say the RB Designs head and carb mods are the best thing you can do to your Gas Gas.

http://www.rb-designs.com/

 

[AZRickD]

Sea level, 98F, and 110% humi-ditty.

What did he take the squish down to for your sea level riding and general mugginess?

 

[john01]

Humm.... my 2010 300 runs very good with the CCK and current jetting but I've been thinking about the head and full carb mods so I may just do it. Thanks for the report.

 

[troffer88]

I have had Ron do head and carb mods on 3 bikes all with excellent results.

 

[john01]

toffer88 good to know, thanks.

 

[gasgasman]

Sea level, 98F, and 110% humi-ditty.

What did he take the squish down to for your sea level riding and general mugginess?

Actually, only 35% humidity. We are in a severe drought right now.

It would not be fair to RB Designs for me to post the final squish measurements.

 

[firffighter]

Ron is the man!

He's done 2 KDX's for me and helped with my fork conversion on 1 of them. He is very professional and can transform your bike. Saving up now for carb and head mod on my 300.


It's also nice that he is only 45 min from my house

 

[prk03]

The carb mods really cleaned up my 250 07. The throttle response is perfect.

 

[mrkartoom]

Good to hear. I've about had it futzing with the jetting on my bike and this is all I need to hear to motivate me to do the same. I've been considering it for a while and was thinking just the head, but I may as well get the carb done as well.

The jetting you aren't messing with is the jetting Rob did or yours?

 

[gasgasman]

The jetting you aren't messing with is the jetting Rob did or yours?

The jetting and needle is all Ron's selection. Ron sent some extra pilot and main jets with the carb for further fine tuning.
All the previous JD jets and needle that were in the carb were returned to me.

As per the instructions with the carb, all I had to do was adjust the mixture screw a 1/16 of a turn at a time until the engine reved cleanly. A 1/4 turn did it for me.

 

[mrkartoom]

Excellent. Did you have to schedule with him or just send your stuff and wait?

 

[gasgasman]

I e-mailed him first to see what his schedule was like. He has a 3 day turn around time.

 

[mrkartoom]

I e-mailed him first to see what his schedule was like. He has a 3 day turn around time.

I should probably email him back again as well. I did a few weeks ago asking for his schedule and he just said to ship it out, so I assumed he wasn't back-logged.

 

[Jakobi]

I should probably email him back again as well. I did a few weeks ago asking for his schedule and he just said to ship it out, so I assumed he wasn't back-logged.

Do it You won't be disappointed.. Even just increasing compression and reducing the squish has improved things alot for me.

 

[mrkartoom]

Yeah I'm hoping for good things and I've heard enough here to be convinced this is a must do. I took her out this past weekend and rang her out pretty good. I love this bike and it is pretty impressive, but I have exhausted my limited ability to dial it in perfectly. I'm going to defer to Rob at this point.

 

[GMP]

Everything about doing business with Ron has been top notch. Turn around, shipping, results. I'll factor in the cost as part of new bike setup, like a set of handguards.

 

[mrkartoom]

That's what I hear about Rob. I myself didn't factor this work in before purchase and perhaps that's because this is my first ever 250+cc 2T. Not a major financial setback so I'll just do it. I assumed I would just fiddle a bit with jetting to get it spot-on then enjoy this wonderful motor everyone raves about, but I have come to the realization I can't get it perfect as it is. Without this site I'd probably be pulling my hair out, if I had any left to pull out.

 

[gasgasman]

I love this bike and it is pretty impressive, but I have exhausted my limited ability to dial it in perfectly.

I was at my wits end. I missed duking it out with Marty Halmaza due to jetting issues.

 

[mrkartoom]

I was at my wits end. I missed duking it out with Marty Halmaza due to jetting issues.

I'm fairly confident in saying that it would take more that accurate fueling for me to give that guy any competition lol!

 

[thumperrider1]

MrKartoom did you end up getting the mod?