RS34 Tuning Assistance Please

Carbs just ultrasonically cleaned...plugs after 200 miles:

#3 seems slightly off  🤔 

Nippon Denso W24ES-U  non-res
Taylor Spiro-Pro Wires
Dynatek 2000- Setting #5  38° BTDC
RPM- 10K   3 Ohm Minicoils
Shindingen SH775-  Roadstercycle 

Carburetor Jetting:
122.5  Main
15  Pilot
.8  Air

Fuel Screws-  1/4 +/- out
Needle Clips-  Middle

🙂


For reference


ZN1100B motor- w/2K miles:
Wiseco K1172
Stock (bathtub) head- mild porting
ZX1100 cams
Crank-  welded...​​​​​​​​sm🥰🥰th!

​​​​​​V&H- 13009-J  baffled

🫠

 

All look a little rich. 
Steve
 
 

Would size 12.5 (or size 10) pilot jets, or lowered needles correct that?

Tried leaner .9 air jets but the engine didn't agree much with that...


🙄

 

If you'll remember we've been through this before. We don't have the same carbs where yours are more modern but similar. In my case I went through all the steps you are going through now. When I changed one thing it effected another. I wound up going to 1.0 air jets and it helped, reset the float level with the parts needed for 50 year old carbs choke plungers etc. , then the plug wire mystery then pilot jets then lowered the needles one step, that helped finally back to the emulsion tubes. The PO had drilled extra holes thinking he was an ace tuner  I soldered up when I started. Going larger on the air jets was a dead end  so I went back to the 1.0's. Still a little rich so I opened up one more little hole on the tubes. Those were the ones Miller did before his brother got his paws on them. Roll on in 5th is great but the mileage is SHT. 25MPG. Bike runs great all through the RPM range, no smoke or anything else so now it's on to plug chops. I've never done them with these carbs so it's long overdue. Strange thing about it when I closed up all the holes the brother from hell made I had larger pilot jets and mains then got 42 MPG but piss poor roll on. I guess plug chops are in both of our futures. Back then it was too hot to do it but now the weather is just about perfect to do it. I'll let you know how it turns out.  
BTW the 1.5 slides you found for me when I started this journey made all the difference.
THANKS AGAIN
Steve

I would stick with the #15 pilot, if you go too small on the pilot it probably won't start or idle (been there)

Was the pilot circuit set with Color Tune kit?

Have you tried a #120 main jet? A smaller main will lean out all circuits but would require adjustments to the pilot circuit (fuel screw setting)

Steve, same carbs...way different engine(s). 

The old motor had compression around 150 psi, but this one is holds 180 plus.

My gut-sense suggests this motor pumps air at higher speed/velocity, which naturally sucks more fuel than before.

Could this engine application be pushing the limit for the RS34 carb size considering how close it is to needing the smallest pilot jet size available...or am I just looking at this wrong?

🤔

Injected wrote:

I would stick with the #15 pilot, if you go too small on the pilot it probably won't start or idle (been there)

Was the pilot circuit set with Color Tune kit?

Have you tried a #120 main jet? A smaller main will lean out all circuits but would require adjustments to the pilot circuit (fuel screw setting)
 

Great suggestions!   

Apparently, I must stop trying to equate RS34 and BS34 carb jetting.  It just seems odd to use the same main jet spec'd by the FSM for a stock 82 KZ1100 motor, when this engine is anything but that.  Lol

daveo wrote:

Steve, same carbs...way different engine(s). 

The old motor had compression around 150 psi, but this one is holds 180 plus.

My gut-sense suggests this motor pumps air at higher speed/velocity, which naturally sucks more fuel than before.

Could this engine application be pushing the limit for the RS34 carb size considering how close it is to needing the smallest pilot jet size available...or am I just looking at this wrong?

🤔

Compression would have something to do with it but not much. The 34's are fine for what you're using them for. When I lunched a piston I bought a 1015 barrel set and I couldn't get the old style Wiseco 10.25/1 piston so I used the stock KZ1000 pistons until I could buy a new set. The jetting wasn't that big of a deal just minor changes. I did notice a small drop in power though. Later I dropped in the new pistons and was back to where I was. The biggest change was when I did the mild porting on this junk head. Night and day. I never had the clutch slip in 2nd gear before. With the 1075 it was much STRONGER than ever. I may look into a smaller main but I think I already did that. I'm going to try by the book plug chops and see where it leads me. 
Steve

daveo wrote:

My gut-sense suggests this motor pumps air at higher speed/velocity, which naturally sucks more fuel than before.

Could this engine application be pushing the limit for the RS34 carb size considering how close it is to needing the smallest pilot jet size available...or am I just looking at this wrong?

Larry C posted a lot of years ago that the RS34's flowed 114CFM @ 10" water on his flow bench open (no stack/filter)

According to your build spec the head/cams are well under what those carbs are flowing.

If you don't want to decrease the main jet try dropping the needles 1 notch.

190    190    185    195
 

After a ride with the competition baffle installed-mid 50° F. air temperature.


No carb changes yet since cool temps will be stuck here for awhile.


🤪

The good advice is muchly appreciated!