what should i do with BS34s

i have a 81 kz1000 with mikuni bs34s that i am rebuilding. on the bike is a kerker 4-1 exhaust and pod filters. i want to get the most power out of the carbs as possible. what should i do? I have read a lot of replys from Wiredgeorge says that bs34s should run #140 main jets and #40 pilot jets. I dont know where to get these. Should i just get a dynojet stage 3 jet kit? HELP PLEASE

bike shop will have them they dont cost much.

BarMan...put Your location in Your signature,ok,so Others will know what links to post,that might apply to You and where You live.(U.S.A.,Canada,Europe,etc.)
Also...put Your bike year and model in there as well...and some brief details about the bike,so You don't have to keep repeating it in topics.

You're probably going to pay more for a "Kit" instead of just the jets needed.(if You only NEED the jets).
Kits are good,if You KNOW what kit to get.
If You're tinkering with the carbs...get a good selection of jets,so You can experiment until You get it ...much cheaper,Bud.

I'd stay away from the Dynojet kit - but that's my personal opinion. WiredGeorge has saved my bacon several times - I'd follow his guidance.

You can get the #140's and #40 pilot jets from Z1 Enterprises. Jeff or Rob can give you additional guidance, they are very knowledgable and helpful, and their prices, shipping and service can't be beat!

www.z1enterprises.com/

Hope this helps.

Aftermarket jet kits such as Dyno Jet often have jets that do not equal stock sizes. A Dyno Jet 140 might actually be the same size as a Mikuni 150.

one more question for you guys about my bs34s... the main jets, do i need the large round slotted type or a different one?

Call Z1Enterprises.com tomorrow and tell them you need #140 main jets and #40 pilot jets for your BS34 carburetors and they will send you the correct ones. If you must know the types, the main jets are N100/604 type and the pilots are BS30/96 type.

wiredgeorge wrote:

Call Z1Enterprises.com tomorrow and tell them you need #140 main jets and #40 pilot jets for your BS34 carburetors and they will send you the correct ones. If you must know the types, the main jets are N100/604 type and the pilots are BS30/96 type.

wiredgeorge, do I need the same jets for my KZ700?

Specs of the KZ700 BS34 carbs:
Mainjet: #105
Needle jet: Y-9
Jet needle: 4BE04
Jet needle clip position: fixed
Pilot jet: 37.5

The needle has a fixed clip position. I think the Dynojet needle has more clip positions. Does that have a big advantage over the stock needles?

Compare a Dynajet jet needle to a stock jet needle. Note it is not even similar. Also note that the stock jet needles come in different tapers/lengths/widths. How is the Dynajet needle going to replace ALL the BS series jet needles and work well? I have found that it is seldom necessary to shim or raise the stock jet needles on any BS series carb. There are two types of jet needle/needle jet combos for the BS series carbs. One likes a #140 main jet and the other a #130 as the factory jet needle is a tad richer through its entire range. I can't remember which type you have since your bike is pretty uncommon but I would buy #40 pilots and two sets of main jets: #140 and #130. Install the #140 mains and if your bike won't pull over 7K rpm, then install the #130s and it should be fine. Buying both sets of mains will keep you from having to wait while a the second set arrives, if they are needed.

wiredgeorge wrote:

Compare a Dynajet jet needle to a stock jet needle. Note it is not even similar. Also note that the stock jet needles come in different tapers/lengths/widths. How is the Dynajet needle going to replace ALL the BS series jet needles and work well? I have found that it is seldom necessary to shim or raise the stock jet needles on any BS series carb. There are two types of jet needle/needle jet combos for the BS series carbs. One likes a #140 main jet and the other a #130 as the factory jet needle is a tad richer through its entire range. I can't remember which type you have since your bike is pretty uncommon but I would buy #40 pilots and two sets of main jets: #140 and #130. Install the #140 mains and if your bike won't pull over 7K rpm, then install the #130s and it should be fine. Buying both sets of mains will keep you from having to wait while a the second set arrives, if they are needed.

Thanks wiredgeorge!

I looked it up in the KHI-manual, and the KZ700 uses the same jet-needle/needle jet combo as the KZ750L (US). Maybe this is a more familiar type of bike for you.
The ZX750 (GPZ750) uses a Y-8 needle-jet and a 4BC6 jet-needle.

Are these the different types you were talking about?