Topic: C R Carbs from dynoman

[topgun]

Just contacted Dynoman about buying CR Carbs for my F1 my smoothbores are getting a bit old and need new manifolds It has a 900kit big head Dyna coils and ignition and a cam in .357lift ex .330 lift, anything else I should consider or need to know from your experiences Cheers Tony

[Retro Rocket]

CycleX has the RS34Mikuni's racked for the 750, they are a far better carb for the street, they have an idle circuit and have accelerator pumps, the CR,s are basically a race carb designed for max revs. I know lots of guys use CR's on the street but the RS34's are a much better option...... Same price.....

http://www.cyclexchange.net/Carb%20System%20Comp%20Page.htm

[Bill/BentON Racing]

+1. RS's coming this way asap.Bill

[Retro Rocket]

Yep, i will run them on my 1000cc bike whilst running it in then swap them over to the 970cc bike, fuel injection is still the plan for the 1000....

[topgun]

Thanks Retro but I thought 34,s would be to big for street work was thinking 29 cr,s a guy had 33,s cr carbs at gatton swap, but wanted too much for 2nd hand.any thoughts on valve clearances for said cam Cheers Tony

[Retro Rocket]

Check your PM's mate......

[slikwilli420]

Im guessing RS34's would be way too big for a stock displacement motor. What carbs are recommended for stock displacement motors to wake them up and add some modern tech to them? I have heard people say that CR29's are like bolting on 10 horsepower but some do not think that is the best route. Just curious.

[jaguar]

I would also like to understand better about the sizing for carbs
what is a range that CR29/31/33s are good?
I seem to remember some place that size is "different" when talking round vs flat slides
34 seems like a big number....
would they work on a 812 or 836?

[Doctor_D]

RS34's also work on GSXR600's and GS750's -- so a CB750 isn't out of the ballpark size-wise. The accelerator pump assures good throttle response despite the size.  The better question is if you can take advantage of them with a stock-ish motor.  The answer there is "no."

A number of people are on track to beating me to it, but I have some RS's that I'm dying to take another run at. Think I'll let them be the guinea pigs this time.

I'm scratching my head over people in this thread and others who keep saying that CR's are unstreetable.  Modern CR's have a decent idle circuit  and mine start and run like champs.  Mike Rieck will warn you that the choke is sensitive to wear and can cause all sorts of headaches, but that's the only real problem I've encountered.

As for sizing, without an accelerator pump, you need good intake velocity to avoid bogging and get good throttle response. Stock-ish and modified motors are fine with CR29's, which will flow enough air and fuel for about 81rwhp. (Ask me how I know.) In my case, that was too small, and I picked up 4.5hp by going to CR31's.