anyone try vm32's? (cb350/360 kit)

[jdmjimi]

Looking into swaping back to daul carbs this spring. Seen mikuni has a vm32 kit for the cb360. Im sure i can work with that kit. The single carb kit is jetted way to rich to try to get it going for a jolopy show this coming spring. Any input on these (ideas, opinions) would be apretiated. thanks

 

[lude]

from what i learned from lots of reading is, they will work, but your gonna spend alot of money on jets, have 5 things in these carbs to change, and no real baseline, so its alot of guess work, i would go vm30s though. and buy them not in a kit, you can get vm30s brand new for about 66 bucks if you shop around. then you just need a high quality cable, and air filters. another thing to note is, vm30-36, are 40mm spigot where the bs34s are 44mm, the stock rubber manifold will clamp down to 40mm however, i tested this myself.


however, i think i have decided myself to go with pwk30s, 44mm spigot only main jet, jet needle and pilot to change to get it tuned, so i picked that rout, brass gets expensive

 

[HoughMade]

What is the advantage of any size VM over BS? If there is a good reason, the hassle may be worth it.

 

[lude]

What is the advantage of any size VM over BS? If there is a good reason, the hassle may be worth it.

better power delivery, sometimes a bit more power altogether, can get vm parts almost anywhere and they didnt change them every year so that right there beats bs'. and in the long run, no diaphragms to wear out, no butterfly shafts right down the middle of the bore for restrictions, and cost, a new vm is sub $100, plus just cool factor.

 

[Charles]

Right...it's a direct draw set up. On the stock BS34, when you pull the cable it opens the butterfly, which affects the pressure inside the carb, which then affects the slide causing it to "vacuum" upwards letting in more air/fuel. With that set up, there's a lag between you twisting the throttle and the bike responding to your input. With the VMs, it's a direct pull slide, so when you twist the throttle, the cable pulls up the slide, not the butterfly. If I'm not mistaken, VMs don't even have butterflies. So basically, you don't have to wait for the air pressure to modulate the slide. You're doing it directly.

I have a couple of questions though. If I used a set of VMs, or even the PWKs, I'd def have to fab up a bracket to hold them together, right? Or no? Given the they're connected by a split cable for the throttle, there's no need for a device to sync the butterflies like the stock BSs. Choke...just pull each plunger individually? I guess I could fab up something to connect those so I'd have a single point for modulation of both.

 

[drewpy]

vm's will give you a snatchy throttle and they would still need syncing to the engine. you use the cables to adjust the slide heights.

good for performance as in WOT applications!

 

[HoughMade]

Well, I have my BS34s perfectly sorted, so it does not sound like a big enough advantage for me. I can understand the appeal, though.

BTW- any lag there may be, I can't feel.

 

[lhaolpa]

I bought a set of 4 carbs from a kz900 kawa and they are slide carbs that work off a common throttle shaft and pivots instead of direct pull on the slides,kind of like a tappet setup on an overhead valve motor.I'm going to hook up the carbs so that air is drawn from both at once,instead of individually like the others were['82 xs400rj seca].I believe I'll get better throttle response and torque. lha

 

[drewpy]

Well, I have my BS34s perfectly sorted, so it does not sound like a big enough advantage for me. I can understand the appeal, though.

BTW- any lag there may be, I can't feel.

not laggy, but a gradual build up of power, which is ideal for road conditions. race apps need instant snap throttle to lay the black snake on the track

 

[lhaolpa]

I still have my newly cleaned and renewed carbs[stock,but want to try the others.I see a few of the VM type on xs650.com,so I wanted to try them,and I bought the 4 carbs for $5.00. lha