Switching CV for VM carbs?

[Sandwichmascara]

Hey guys

A quick question how can i get 78 GS750 slider (vm) carbs to fit a GS1000 i think of the same year maybe 79/80 with Cv carb inlet rubbers?

the short story i run a GS750 chop but the rings have had there day so to my relief my dad has said i can use his GS1000 lump till i rebuild mine great news.

But and there is always a but the cv carbs with the GS 1000 lump are in poor condition as been sat a very long time and not in the best of shape with bits missing or broke after having a good look at them. so i was wondering if my vm carbs would fit?

i know there a little smaller but i'm sure i read somewhere either on here or another site that slider (vm) cards have better fuel/air flow as they don't have the butterfly in the way etc etc ( please correct me if wrong) and i have main jets falling out my head as my dad runs 5 GS's from 550 to GSX1100e so im not worried about re-jetting the carbs.


so the big question is do i spend money fixing the CV carbs to work while i use the GS 1000 or to i get mine running on it?

there both 8 valve if that helps too.

so let me know what you think

cheers DAN

[koolaid_kid]

The VMs are smaller in diameter at the throat, so you would have to do some mods to connect them.
You (and your dad) would be better served if you rebuilt the CVs (which did not come out until 1980) so both bikes would be runners at the end.
Since your dad's bike is an 8 valve, it is a shaft drive G or GL (cruiser with stepped seat) model.

[Sandwichmascara]

So would i have to ''pack the inlet to make the sit right?
as to be honest i love my slider carbs and want to keep using them

and right ok ill remember that 1980 cv's came out and the engine is chain drive. not sure if being in the uk this changes things?


He don't have the bike for the lump so i can not comfirm the year or model all i know is its been sat waiting for his chopper frame to be finished so he can fit it later this yeah

[GSX1000E]

Concider that this is coming from someone who is currently doing an '82 1100G build that is using 29mm smooth-bore slide carbs. Rebuild your current set of CV carbs or buy another used set to rebuild.

[Sandwichmascara]

Concider that this is coming from someone who is currently doing an '82 1100G build that is using 29mm smooth-bore slide carbs. Rebuild your current set of CV carbs or buy another used set to rebuild.

i hear you man ill rebuild the ones i got thinking about it im sure i saw a set at the back of my dads garage a couple weeks back.

cheers for the help

[kymasabe]

Personally, I hate CV carbs. I have a GN400 with a VM36 on it that runs MUCH better than the original CV carb the bike came with.

[tkent02]

Depends entirely on where you ride. Any significant changes in elevation and the CVs are the only way to go. Florida, yeah VMs are good. Colorado, not so much.

[salty_monk]

Not much elevation change in the UK... Not compared to some parts of the US anyway.
You probably saw most of it when you toured Scotland on the Beemer..

Can't see him riding a chop to the alps..

I would rebuild the CV's too. Nicer ride and easy to rebuild in my opinion (I've had Gs1000's with both types fitted).

[1_v8_merc]

Had good luck with VM's...I never clean them, and they keep firing up every season..where-as the CV's begin acting up without cleanings.

[tkent02]

Does no good if I have to stop and change jetting halfway up a pass. Never had a problem with CVs acting up, but I don't let them sit for months either.

[Big T]

The VMs are smaller in diameter at the throat, so you would have to do some mods to connect them.
You (and your dad) would be better served if you rebuilt the CVs (which did not come out until 1980) so both bikes would be runners at the end.
Since your dad's bike is an 8 valve, it is a shaft drive G or GL (cruiser with stepped seat) model.

You forgot the 1980 GS1000E model, which is what I'm assuming is what his dad has

You can modify some VM boots from a 78 or 79 GS 1000 to fit the motor, or rebuild the CV carbs

[Sandwichmascara]

ok thanks for the replys in the end i have rebuild the CV carbs but i have also got my hands on a 78 750 lump with another set of VM carbs

but alot of the heads for the screws are rounded or well on the way any body know what thread and size they are as the cv ones are alot bigger maybe m3x14mm?? and ill get new ones before i fit them in the bike