BS34's on Bored & Cammed J Motor?

Anybody running these carbs on a built engine? Any hints?

You can get them to work, depending on the mods, but you'll probably be disappointed in the performance. A set of Mikuni RS's or Keihin's FZR's are easier to tune and give far better performance.

don

What kind of intake and exhaust?

Very important...

I just needed to keep my rpms us above 3500 when I needed to gooooo. Great gas mileage.

2 words: Jet Kit. They will work fine. I have never had a set work without a jet kit, you need the needles from the kit, they have a differnt taper then the stock ones. If you want all out performance yes RS Mikunis are great but they cost over $700.

I have a Gpz1100 motor bored to 1135 and stage 1 street porting with a Kerker KR pipe. I could never get the BS34's to work right. I bought a lot of jets, needles and used a jet kit, nothing worked. I went so far as to think maybe the carb set I had was bad and bought another set of BS34's. Ended up with the same problems as the first set. It was way to lean on the pilot circuit and when I was getting the pilot circuit richened up the changes would effect the midrange. I waisted a lot of time and money on them.
I bought a set of Wired George's VM30 perfomance carbs. Those worked a lot better than the BS34 but I ended up finding a set of RS36's at a really good price and bought them. The RS36 are fantastic, very little tuning involved, I LOVE them.

TeK9iNe wrote: What kind of intake and exhaust?

Very important...

Baffled Kerker and air box w/K&N filter. Its not my bike. Its "Kims" from the other forum. You guys have hit on all the topics Ive tried to explain to him with no avail. He's built a killer of a J motor and running BS34's rebuilt by George. I dont think George was aware of the bore or the cams when Kim sent his carbs off...Kims convinced the IC-Igniter is to blame for the poor low rpm attitude of the motor. The bike runs good in the upper R's but stumbles in the low ranges. Do bad IC-Igniters work at high or low rpm's and falter in other ranges? And Thank You for the responses!

Highly doubt the IC ignitor is at fault. More like the change in vacuum do to the camshaft timing. It might be lean down low. Like any carb, it may improve with tuning. But how much will it improve vrs cost of jets/ kits, over a set of better carbs.
I'm still using the BS34's, but have changed to a set of GPZ cams and it has altered all the settings. I have a 3/4 throttle rich stumble, which I'm trying to sort out. Idle is fine, low speed is of course a bit less torque from the stock cams. Mid range is real good, top end excellent. But 3/4, well I'll try a few more things before switching out to some other carb rack.

It is not you IC ignitor I thought the same thing on mine and replaced it with a known good one. Nothing changed, they either work or they don't. You will NEVER be able to tune those BS34's to work the way you want them to with a modified engine. Remember the BS34 were designed to operate with specific vacume signals. When you modified that signal with the engine changes, you exceeded the design parameters of the carburators and no amount of tuning will change that. Don't make the mistakes I made just get a set of good peformance carbs, you will be very happy with them.

Thank you baldy...Thank all of you for your responses! ~Michael Hill~ I live to romp & stomp them $30,000+ v-twins with my 32 year old "Built in the USA" "Muscle Bike!"