In case anyone is on the fence on getting the RS series carbs, do it. I just installed the RS34 onto my KZ900 and what a difference in power, Wow! I was running a set of VM26 bored to 29, the bike ran great but it just felt I was leaving some power on the table. I bought the 34 and dialed them in today, judging by my butt dyno I swear I gained 20HP. It carburates clean and pulls really hard from idle to redline. It feels like the bike is "uncorked" now. It'll rip my arms off when I really get on it, it's pretty addicting. I've run a set of RS36 on my ELR clone and was not disappointed with those either. Here's my jetting and mods to the engine.
1075cc MTC 10.5-1 comp pistons
Yosh drop in cams .395 intake .385 exhaust
Vance & Hines 4-1 exhaust
Needle in the middle slot
P-4 needle jet
Float level set with the wet clear tube method at the top of the float bowl. That is 23mm float setting. Mikuni recommends setting them at 17mm but to me that seemed really high when I clear tubed it that set the fuel level about 2mm below the overflow tube so I lowered it. Haven't found a running issue with lowering it.
Idle mixture screw 1/4 turn
This gets me just about perfect. I've yet to vacumm synch them but they idle pretty good.
Same experience here. They work great and really wake these old bikes up. I was running 29mm smoothbores my KZ1000 prior. I also have a set of RS34 carbs on my KZ750 twin and that thing completely transformed. In the instance of the KZ750 twin they saved about 3 pounds in weight as well. I know some people don't like the sound they make but I love the rattle when you roll on the throttle.
Another vote in favor of the Mikuni flatslides. I have a rack of RS34's on my warmed over KZ1000 LTD. Also, have a pair of RS34's on my '70 Triumph Bonneville (now 750cc w/ported head and cams). The throttle response is crisp on both setups. And the KZ really comes alive at higher rpms. No complaints here.
Presently - 1980 KZ1000B4 LTD w/mild ported head, 1015cc Wiseco, Falicon Supercrank, R&D undercut trans, +2" swingarm
In a former life - KZ-based dragbike - CrMo car tire chassis, 1395cc, Hahn Racecraft turbo system, VP C16, Orient Express 3-spd auto, 7.80's @ 165-170.
Like baldy110, I had the floats adjusted to lower the fuel level at one point, but decided to reset them to 17-18mm. per Mikuni recommendation.
Had to bend the tabs an awful lot to achieve 22mm, and it just seemed awkward to do something that Mikuni had not suggested in the manual. Nowhere could I find a reference to use the clear tube method for the RS carbs, or to set the levels 2-3mm fuel level below the bowl top. I did use the clear-tube to verify that the levels were the same across the set...
I found this nice little tool that makes on-bike main jet changes a breeze:
Yeah the ease of tune-ability is a major bonus. Changing the needles can be done with the carbs on the bike rather than dissembling half the rack. Heres RS-34s on my kz750 twin. The stock carbs on the twin are terrible in comparison.
The ease of tune-ability is awesome, but a pain to access with an air box in the way.
I recently reconfigured my air box to fit velocity stacks and RAM AIR filters. Once those have been removed through the air box, access to the Pilot Air Jets becomes unobstructed. Those jets are a pain for their size, but especially to get their tiny threads aligned and started correctly.
1982 KZ1100A-2 (sort-of)
January 2016 BOTM
The following user(s) said Thank You: Dragbike_Mike
baldy110 wrote: I like your air box idea, really clean. Am curious Dave what was your final carb settings and what did you do to the engine?
0.7 Pilot Air
Stock Needles-Center Slot.
Stock Needle Jets
Pilot Fuel Screws-1/4 Turn
KRS-004 Mikuni Stacks
117.5 Main Jets messed with the low-end jetting, so I put back the 115's before pack-down. Will likely play with the jetting again in the Spring.
Engine is stock other than:
G1135-3 MTC piston kit w/cyl. bored and prepped by Pit Stop Performance.
Stock ZN1100 bath tub head milled .005 in 2015 for flatness; valves/seats touched up and Viton seals installed.
1984 ZX1100A camshafts using the stock ZN shim-on-top valve buckets.
APE Cyl Studs/Nuts, and Cam-Chain Adjuster
Non-Smog Cam Cover
Bike is stock other than:
Dynatek 2000 with Mini-Coils, Copper Wires, Res-Caps, Non-Res U-Groove Plugs.
V&H 13009-J Header w/Street or Comp Baffle
Progressive Shocks (12.5"), and Fork Springs
HEL SS Brake Lines
160 MPH Speedo