CV carbs vs mechanically activated slides

[garyS-NJ]

Im wondering if anyone updates their old gs bikes with later model CV carbs.

I have my '79 gs1000 running pretty good with the stock VM 26's jetted for pods and a 4:1 (& my own muffler thing which has no muff but employs an antireversion cone for transition and s reducer at the outlet, idk what I was thinking but it works well). I also put tubes in the pods and taped off some of the outside surface.. I went I think 2 clicks up on the mains and stock pilots (I have the next size up pilots (17.5 from 15's?) I might try but it's running pretty good except for a lug at slow roll on from a stop (seems to want a goose and snappy clutch work).

Back to my post.. so before I got the gs1000 dialed in I got a set of bst33's from a katana600 I parted and then also a set of bst36's from a kat750 and I WAS thinking about trying the bst33's. So that's just brewing in my head (I know I would need some slick adapter manifolds, ideas?)..

I just found a set of tk26 CV carbs (cheap) from an early 80's kz550 and was wondering if these might be desireable to the kz community or adaptable for a gs750 (i have vm26's on that gs750 now with pods running ok). Checking on ebay, seems more of the mechanical slide vm's and keihin are sold for UJM's.

Thoughts??

 

[Steve]

To properly adapt to CV-style carbs, you will need to have adapters, because the CV-style carbs are larger. For example, newer versions of your 1000 have BS34SS carbs, the 26s you mention are simply too small. In fact, the GS550 through the GS850 all use BS32SS carbs.

.

 

[Guest]

Take the tape off the pod filters, you're robbing the engine of airflow which is one of the reasons pods are put on in the first place. Put your stock pilot jet back in, 17.5's are often too big. Try 15's with the fuel screw turned 1.5 out from the bottom. Then up the main jet substantially, sometimes 5 sizes over stock is necessary if not more. Once that is sorted, adjust your needle clip position down one.

That should get you close.

 

[Big T]

Sounds like a lot of work for zero gain

Remember the VM 26s and BS 34s deliver the same HP and are equivalent in air flow

Plus, the BS carbs are a lot harder to tune for pods and it seems you don't have that dialed in yet in your current configuration

 

[garyS-NJ]

Thanks Steve. I wasn't thinking of trying the TK 26's on my GS1000 but rather will I find KZ550 owners that want them over round slides/. And as for the BST33's, 34's or 36's on my GS1000 do any make sense over the VM26's and if so, do you know which adapters bolt on?

To properly adapt to CV-style carbs, you will need to have adapters, because the CV-style carbs are larger. For example, newer versions of your 1000 have BS34SS carbs, the 26s you mention are simply too small. In fact, the GS550 through the GS850 all use BS32SS carbs.

.

 

[garyS-NJ]

Thanks, Special K, just found some old notes about the pilots and mix screw. and if I can understand what I wrote, seems it came with 20 pilots and I tried several mix settngs, then did same with the 15 pilots and somewhere in there I bought 17.5's but never installed them as it ran pretty good after the pod mods/. Looks like I ended at 1.5 turn fuel ad 2.75 turns air mix. all this was after going way up on the mains (I think I started 1 click up from stock and went up another 4 jet sizes. and I'm not sure how much airflow I'm "robbing" considering the exposed area compared to the stock airbox
opening and that it seemed to lean in the midrange before that and it seems to run pretty good now

Take the tape off the pod filters, you're robbing the engine of airflow which is one of the reasons pods are put on in the first place. Put your stock pilot jet back in, 17.5's are often too big. Try 15's with the fuel screw turned 1.5 out from the bottom. Then up the main jet substantially, sometimes 5 sizes over stock is necessary if not more. Once that is sorted, adjust your needle clip position down one.

That should get you close.

 

[garyS-NJ]

good points Big T.. I didn't know how the BST33's or BST34's faired against the VM26's or if the BST 36's would add any performance or streetability. Right now unless I get my Kat1100 BST34's working right, the BST36's might go on the Kat 11. Again,the point of my post was those TK26 CV carbs - sellable or garbage... (I assumed too small for my G1000 bc they came off a KZ550 (unless jets would do it)

 

[Big T]

Hmm, are you talking about the fuel mix screw setting, or the air mix screw s?

Yes, the TKs are way too small for a 1000

 

[garyS-NJ]

Fuel screw and air screw

Fuel screw and air screw

I listed my final setting on the fuel mix and the air mix with seems to indicate that my pilots are aboutf right sized

Hmm, are you talking about the fuel mix screw setting, or the air mix screw s?

Yes, the TKs are way too small for a 1000