GS 850 Carb swap

[andrewk]

Hi all-

I'm an old returning member here- hopefully this isn't a beat to death topic.

I'm working on a 1980 GS850 with the CV carburetors. Bike is in great shape, other than it will not do anything but idle. If the throttle plate is opened at all, the bike dies out.

After a lot of screwing around, I know this is a carburetor issue- Not sure the exact issue, but someone has been chasing this problem for awhile- sealed air box/filter, new intake o-rings, etc. Carbs are very clean, and I've hot-tanked them twice now with no improvement.

I have a set of VM carbs off a early 850, but the intakes on the bike now don't fit. Am I able to just get early intake boots to use the VM carbs? Or are the heads different too?

Any help is appreciated-

Andrew

[7981GS]

The bolt pattern for the screws that retain the manifolds for the CV carbs are wider,
the O-rings that seal them are in different locations and besides that,
Why would you WANT to REDUCE the flow on the intake side?
Suzuki went to the larger sized ports to improve the flow.
Find a set of 34CV carb bodies and rebuild them instead.
(They fit the manifolds that you currently have.)

Several members here have extra sets as well as myself and you should be able to pick up a set for about $50.00.

Daniel

[BassCliff]

Hi Mr. andrewk,

Actually, the carbs are Mikuni BS32SS CV-type carbs.

Yes the heads are different due to the difference in the intake pipes and carb throat diameters. Have you followed the Carb Cleanup Series procedure when disassembling and cleaning your carbs? Did you remove the caps from the idle mixture screws so that they can be removed and those passages cleaned? Did you order an O-ring kit from http://cycleorings.com to replace all of the O-rings in all the carb bodies? I'm just trying to be thorough. Your symptoms are classic for incomplete carb cleaning.

These symptoms may also indicate way too much air in the mix, but you said you have sealed the airbox and the rest of the intake system. So I'm thinking that there is still some goo in the smaller passages of the carbs.

Anyway, since you've been gone a while, let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[imfrikkinawesome]

I'm in a kind of similar situation. Except the bike I bought came with incomplete 32s and they seem to be a difficult carb to find

[Steve]

It's actually a very popular carb for the GS series. It was used on the 550, 650, 700, 750, and 850, but with different jetting.
The 550 and 650 sets had different throttle shafts for a slightly narrow spacing between #2 and #3, but the bodies are the same.

By "the same", I am speaking regarding size of engine, not placement of carb. Each carb is unique to its position in the rack, so if you need a #2 carb, only a #2 carb will work.

.