[strat71]

Bike: 03 Iron Barrel
Carb: Mikuni TM32
Filter: Ace Canister
Exhaust: Indian Headpipe and English Short Bottle
PAV: Gone
Altitude: from sea level to ~140m
Temperature: from 26 to 32°C
Pilot Jet: 25 - 1 and 3/8 turns out on the Pilot Screw (+ or - 1/8 turn)
Main Jet: 185
Needle Valve: P-4
Needle: 5FP17 (Stock Needle) Clip in the 3rd position from bottom + half shim (I.e. 2.5 position from bottom))
Throttle Valve: 4.0 (Stock Throttle Valve)

Note: i spent time finding the right jet combination, unsuccessfully, but it turned that the spark was weak. i fixed the ignition and since, it's been very easy to find the right setting... the bike starts very easily with the Kickstart, the idle is smooth, the bike pulls nicely when you need power... turns like a swiss clock..

[Mandar_C500]

Hi,
     I have a query regarding Jetting and Niddle setting.
I own a classic 500 (EFI model) I have removed EFI system and installed a CARB (UCAL33 / BS33) which comes with UCE 500 carb model in India.
I have installed a UNI foam filter and raised the needle by adding a small spacer, however not changed the jets.
Do I need to change the Jets, if yes then pilot or main jet or both?
Is raising the needle is same as up-sizing the main jet?
I have not checked the plug color however bike has a flat spot at 80 KMPH.

Have not check spark plug yet
Regards
Mandar

[heloego]

   Well I think I finally dialed it in! 

   '06 Electra X
   Mikuni VM32 (Round Slide)
   Goldstar Exhaust
   Same paper Air filter ACE supplies with his Canister with re-purposed Triumph Fork Gaiter as manifold.
   Average Altitude: 5500ft/1.7km
   Current Average Temps: 65F/18-19C
   
   Pilot/Air Screw Out: 3/4t
   Pilot Jet: 30
   Needle Jet: 159P6
   Needle: 6DH2, Clip in Slot #3 (middle)
   Main Jet: 170

   EDIT: Also keeping #s 165 and 175 Mains neatly packed in the tool bag for those trips to other altitudes. 

   Plug looks good, snappy response and no dead spots in all throttle ranges.
   Pulls very nicely across the board and uphill.
   Opening to Full at 75mph/120kmh gives me a nice smooth boost, but the front end gets wobbly so I haven't explored the full potential yet.
   
   

[DanB]

Hey heloego

Didn't you out in a P6 needle jet in place of the Q6?

[heloego]

Absolutely right! 
Above post edited to correct jet. 

[creaky]

Heloego, Your post sounds the closest to my bike so maybe you can help me here? Iron barrel 2006 Classic with standard muffler. Recently bought Mikuni VM32 and is now jetted as follows.
Pilot 30
Main 180
Needle 6DP17
Needle jet Q6
Clip in middle slot
Slide is 3 (standard)
It has a POD filter
Runs ok but I feel it could go better. I don't want a loud muffler hence the stock one. Recommend a free flow muffler that is not too loud if you can. I have experimented with a main from 150 to 250 and a pilot from 25 to 35. The only time I got it running any good at all was when I replaced the recommended 6F05 needle jet with the 6DP17 which was on the carby as delivered. I started a post on O2 gauges which I have temporarily fitted but no matter what jetting I use it tells me it is too rich even though the plug looks ok.

[ace.cafe]

Needle jet is way too rich.
Try P4 or P6 needle jet.

[creaky]

Ace, When I bought the carby it had the following:slide 3, main jet 200, pilot 35, needle 6DP17 and needle jet Q6. The recommended jets I bought with it were:mains 230,240,250, pilot 30, needle 6F05 and needle jet P5. With the recommended jets etc it ran so badly I had to experiment and finally found the needle jet P5 was the problem. With the Q6 installed just about any combination of the others worked OK but the best is main 180, pilot 30 or 27.5, needle 6DP17 and jet Q6. Needle in second richest slot. I have a temporary oxygen sensor installed which now tells me the mixture is correct through the whole range. What has me stuffed though is I don't notice much difference on WOT with a 150 or a 250 main jet.

[ace.cafe]

Maybe they changed the numbering on the VM needle jets? I have never seen a Mikuni P5 needle jet number. They are all even numbered jets in all the listing that I have seen.

All the ones we use on the TM32 are the same as yours, except we use P4 or P6 needle jets. At least 75 bikes out there running great with that combination.

If it runs well with the Q6, then leave it. The TM 32 comes with a Q6, and we have to take it out.

I don't know why you see no differences in performance of widely differing main jets. This is not typical. Maybe do some plug chops.

[heloego]

   Sorry for a delayed response. Real life issues always take precedence. 

   Ace:
   Yes, the VM series do have odd numbered Needle Jets. I had considered going from a Q6 to a Q5 until you advised the P6. Glad I took your advice! 

   creaky:
   Close is kinda like hand grenades when you compare an IB 500 with stock exhaust to an AVL 500 with free flowing. I think the stock 2006 IB has the coated header with a 2-stage Cat in the silencer, correct? Or maybe it was only the case with the AVL. Dunno.
   I could only make suggestions in this case, but this worked for me, so if anyone else feels like correcting or confirming anything I say please, please, please feel free to do so. I will not be offended since this has been (and will continue to be) a learning process for me, too.

   This helped me a lot, as it gave me a map to follow. You may already have this, but maybe someone else can use it, too:
      http://www.mikuni.com/pdf/vmmanual.pdf
   I highly recommend downloading and printing it.
   Page 14 is a good Troubleshooting section to determine Lean or Rich performance conditions.
   The last page shows the throttle settings on the left and which Needles/Jets come into play at the various throttle settings on the right.
   I don't know what assumptions Mikuni makes regarding breathing on the Main Jet Tuning Calculator but it worked for me with the Goldstar system. I ordered up a Main Jet Kit (4/042 series with #70-#230 main jets) from jetsrus.com and it came with a calculator, but the calculator alone is also available cheap all over e-bay.
   
   Ensure your Air Filter is CLEAN! Accumulated dirt or over-oiling will definitely degrade performance. This is even more important with restricted breathing such as with a stock exhaust. If your filter is dirty or over-oiled and you start messing with your jetting, changing to a clean filter later could just give you a leaner condition and may require re-jetting.
   Ensure there are no air leaks on the intake side. Any crack or bad seal will automatically make for a lean condition and reduce performance.
   You say it "runs OK now, but could go better". Is acceleration poor across settings? Maybe go richer on the Jet Needle a slot? Mines set at #3 position (middle) and runs well. Any slot adjustment (Fuel Ratio) IMHO is the very last step you'd need to do, especially if performance suffers at all settings.
   Do plug chops for each throttle setting. At idle with no load, and at all settings under load. That will tell you more than an O2 gage whether you need to go leaner or richer with that particular needle or jet. A gage can be out of calibration and give an erroneous indication. Plug Chops don't lie.

   As for a silencer recommendation, I'm using a Short Reverse Megaphone on the UCE and a Goldstar System on the AVL. The Goldstar system doesn't strike me as particularly loud compared to the Reverse Meg.
   
   
     
   
     
 

[creaky]

Heloego: Yes it has a stock engine pipe but I cut out the Cat thingo which was a lumpy thing at the muffler end of the pipe. I have had the Goldstar muffler recommended by a few people so I might go down that track. Just don't want it too loud. I did a plug chop at around 3/4 throttle and the plug looked good. And re the O2 gauge it was giving me false readings because I had not connected its heater wires which I was told was unnecessary. However they are required to get the sensor to the correct temperature. Now it shows I am running a near perfect mixture at all throttle opening except a bit rich on idle even though I have changed to a 27.5 idle jet. May try a 25 which I have somewhere.

[heloego]

   Happy Days!
   A guy at a local shop advised me that if you run too rich at idle and have to turn your air screw out as much as 2 3/4 turns it's advisable to go to the next smaller pilot jet. The 27.5 might just be the ticket. Just remember once you've reached your fastest rpm with the screw to turn it back in about 1/4 turn so you don't idle too lean.
   Glad to hear you've sorted everything! 

[Yamahawk]

OK! Finally got the carb settings ironed out for my bike, so here they are!

BIKE: 1996 Royal Enfield Bullet 500 Iron Barrel with stock bottle muffler.
CARB: Mikuni VM34
MAIN JET: 200
NEEDLE JET: P6
PILOT JET: 25 and 1 to 1.25 turns out
NEEDLE: Stock needle on groove 4 from top (next to full rich)
AIR FILTER: K&N clamped on the carb bell

After trying several combinations of needle jets, main jets, and needle clip settings, this is what I settled on. Initially, I tried a P8 needle jet, and a 210 main, needle on 4th clip from top, and it ran really strong but the plug was black and sooty. I was running a B7ES plug, which is hotter than the stock plug, so I knew it was pretty rich. Then I went to a 200 main, needle in the middle clip, and a P6 Needle jet. It didn't pull as strong, but ran well. So, I put a couple hundred miles like that, and the plug seemed a little too white, and so I installed a BR8ES I had laying around, and also put the needle clip in the 4th position. Now, it pulls very strong, and the plug has a brown color. I think I will run it like this for a while, then check the plug again.

[Dave1]

Well here are my successful carb settings. Bike is Royal Enfield Iron Barrel 520 cc, 9.6:1 compression, Bullet Whisper ASBO19. Gas flow and ported head, standard valves, K&N air filter, trials exhaust. Not going to mention all the modifications as not all of them are needed here.

Carburettor : Mikuni TM32
Main Jet : 210 Hex jet ( 4/042 )
Needle Jet : P4 ( 389 )
Pilot jet : 27.5 ( VM22/210 )
Needle : 5FP17 ( 3rd groove from the top )
Slide : 4.0

This is the latest settings as of today. Air temperature is 22 degrees Celsius, 60% humidity. 167 feet above sea level. Bike pulls well all through the rev range to 70mph indicated.
 
                 

[Royal Stargazer]

I was so excited to finally post here after getting my carb all dialed in, but held off because the thread had been dormant for awhile, but now that's not an obstacle anymore...

The bike is a 2003 Bullet 500, bored out to 535cc with an 8.5:1 piston, Mikuni VM32 carb, K&N filter, and free-flowing '50s-style exhaust, no baffle (the tone is wonderful, maybe a bit louder than I would have otherwise preferred.) I've also removed my oil catch can.

Pilot: 27.5
Main: 210
Needle: 6DH2, fifth position (rich)
Slide: 3.0
Air screw out 1-1/4 turns

I have no idea what my air jet or needle jet are.

At 850 - 900 ft above sea level, mid 60s to mid 70s F with low humidity, the bike runs like a charm. It was still a little on the lean side (especially at WOT) when temperatures were in the mid to upper 80s, so I can tell next summer or a particularly intense Indian summer will call for me to swap in a 220 main, and maybe that 6DH4 I've been sitting on.