RB mods jetting... database to build

[ucrtwf]

Hi Guys,
I've looked through the jetting database, but with all the different needles,mods, etc, it gets pretty hard to get a feel for what to start with. I would be all for putting together a separate database for the typical RB mods. I'm going for my first ride this weekend with the mods, and I'd like to get a feel for where to start. Weather is suppsoed to be mid 40's, 1000 ft elevation. I know nothing will be perfect from the start, but I'd hate to spend a bunch of time getting close, or blow the thing up. I think this would be helpful for many, including new RB modders.

Ron set my carb up with-

RB head mod
RB carb mod (which includes)
Bored to 38mm
Slide mod
air screw mod
Air screw- 1 turn out
Needle- CEK
needle clip- 3
Pilot- 42
Main-178

Any takers?

 

[Jakobi]

I believe Ron usually sets it up pretty close. I'm not sure how many people change the CEK out for double or triple tapers once the mod has been done.

Your changes will also vary depending on how you ask Ron to set it up re squish and compression. In some way increasing compression you'll need to add more fuel, but then tightening the squish you'll get a more efficient burn requiring less fuel.

Its very likely that you could safely start with the exact same jetting specs you previously had and make minor adjustments from there.

My experience with the S3 head was that the jetting stayed the same but the power delivery was stronger and crisper for the same clip. If there was any difference it would be around 0.5 clip pos.

 

[ucrtwf]

Thanks Jakobi,
I just had Ron do his normal optimization for the head. I just asked him to stay in the "pump gas" range, and he said he would. I took the bike out for a quick spin down the street, it's still cold (was 35 'F), and I bumped up the main to a 180, it seemed pretty strong with a hesitation around 3/8 throttle. I'm sure I'll mess with it some, I just didn't want to get on a trip and have the guys wait for me to tune my bike this weekend.

 

[Jakobi]

Another consideration is that will vary from bike to bike will be the amount of material that has to be removed. A stock bike can have anywhere from 1.5 - 2.8mm of squish so depending on where you start and finish it will make a big difference.

You also had the carb mod done, which I personally have no knowledge at all in on its effect on jetting.

What was your specs before the mods?