Carb options 81 GS1000

[doctorgonzo]

I've been trolling ebay recently trying to find a spares set of 34mm Mikuni CV carbs for my 81 GS1000G (slightly torn diaphragm in #1, plus know I need a spare set going forward if I plan on having this bike for many years) , so far with no success. I've gotten a bit of confusing info from the threads in here, so maybe the suzuki hive mind can kind of answer all my questions in one swoop.

First, one of the reasons I put in the performance mods section...
A switch to VM carbs is out of the question right? They would require a head swap, and even then might be too tall for the frame and tank...

The smoothbore carbs are a racing carb. Meant to go from idle to wide ass open with not much response in between making them not practical for street use...

Finally, any 34mm Mikuni CV carb from that general era will work as far as parts go. They might not mount as a rack, but if broken down the individual components are the same. So it doesn't matter what bike they come from...

[coltrain]

Mikuni BS34 carbs I believe is what they are called. Fantastic carb IMHO. Why stray?

[doctorgonzo]

Mikuni BS34 carbs I believe is what they are called. Fantastic carb IMHO. Why stray?

Yes, it's the BS34. Probably won't stray. Wanting to know if all the BS34 are individually the same no matter what model they are on. The rack might differ, but each carb is basically the same as far as the internals, etc... fitting one from the other.

As far as the VM, those that have them are lucky I think, Better response, more simple design, easier to tune, etc...

Smoothbore, I see them go by on ebay on occasion, just making sure my thinking on what they are is correct.

[chef1366]

The main air jet differ from the 8 valve and the sixteen valve.
Do you have a G model? I have some spare carb bodies and diaphragms.

[TheCafeKid]

Yes, it's the BS34. Probably won't stray. Wanting to know if all the BS34 are individually the same no matter what model they are on. The rack might differ, but each carb is basically the same as far as the internals, etc... fitting one from the other.

As far as the VM, those that have them are lucky I think, Better response, more simple design, easier to tune, etc...

Smoothbore, I see them go by on ebay on occasion, just making sure my thinking on what they are is correct.

Smoothbore has its pros and cons. VMs are good carbs, but actually the response CAN be better, and it CAN be worse. The BS type CVs, and I thought id never say this, have proven to me, properly tuned, to be the best STREETABLE carb of the line.

Think of it this way, as so apptly explained in a discussion i had one day with Steve.

On the VMs, the slides are the butterflies. They open, as you turn the throttle. Think of them as a TWO BARREL car carburetor. You wack the throttle open suddenly, and suddenly there is no vaccum pull from the motor, or very little, till it catches up.

On the BS cv type, imagine them as a FOUR BARREL carb, with vaccum secondaries. The BSs have a butterfly valve, which opens as you twist the throttle. Then, as the vaccum pull increases, the slides act as the vaccum secondary valves. The greater the vaccum pull, the more they open. When you wack the throttle on these, the primary butterflies fly open, giving all that you need intially, then as the vaccum increases, the secondary slides open, feeding more mixture. If tuned correctly, the delay is nearly un-noticeable. However, poorly tuned BSs do have a bit of lag to them.

If you want instant response, but arent the type to rip the thottle to WOT, you might like the VMs better ( I like em on the cafe, its not a drag bike, its meant to come out of the turns with a quickness) If you like smooth response, even performance across the board, you might like the BSs better.

Smoothies are a beast unto themselves. They are very on/off. Herkey jerkey. Great for racing, but not so great for heavy handed street riders.

[doctorgonzo]

Sent you a PM Chef. If I Can replace the torn diaphragm for less than the 80 bucks wanted for a new one, and get my o-rings from cycleorings installed, I should be good for a while, I hope.