GSX-R 1100 40mm cv carbs on a GS1100?

[maicojoe]

Was just wondering if anyone on here has used Mikuni 40mm flat slide CV carbs from a 1993 or so GSX-R 1100 onto a 1983 GS1100e. The GS1100 has a 1170cc kit, ported head and performance valve job with stock size valves, V&H pipe, and K&N pods. If the spacing on the rack is wrong, can I mount the newer 40mm carbs to the older 34mm cv rack, and use the corect shafts and linkage? That, and since I dont really want to use a stock air box, does DJ offer a stage 3 kit for the newer 40mm carbs?
Thanks, Joe

 

[gearhead13]

Was just wondering if anyone on here has used Mikuni 40mm flat slide CV carbs from a 1993 or so GSX-R 1100 onto a 1983 GS1100e. The GS1100 has a 1170cc kit, ported head and performance valve job with stock size valves, V&H pipe, and K&N pods. If the spacing on the rack is wrong, can I mount the newer 40mm carbs to the older 34mm cv rack, and use the corect shafts and linkage? That, and since I dont really want to use a stock air box, does DJ offer a stage 3 kit for the newer 40mm carbs?
Thanks, Joe

I had a set of these that I tried on mine. A REAL bugger to get on the 1100 or 1150 boots. DJ does not sell a kit AFAIK. You could talk to Factory pro and they could help you. Finding pods for them might be tough. Depending on what year they are off of the spacing might be close or close enough.

 

[Guest]

Was just wondering if anyone on here has used Mikuni 40mm flat slide CV carbs from a 1993 or so GSX-R 1100 onto a 1983 GS1100e. The GS1100 has a 1170cc kit, ported head and performance valve job with stock size valves, V&H pipe, and K&N pods. If the spacing on the rack is wrong, can I mount the newer 40mm carbs to the older 34mm cv rack, and use the corect shafts and linkage? That, and since I dont really want to use a stock air box, does DJ offer a stage 3 kit for the newer 40mm carbs?
Thanks, Joe

The spacing is wrong with these water cooled carbs.
You need oil cooled 40mm cv carbs that were on non-USA 91-92 gsxr1100.

 

[posplayr]

The spacing is wrong with these water cooled carbs.
You need oil cooled 40mm cv carbs that were on non-USA 91-92 gsxr1100.

I think the 40 mm (BST40SS) were in the US just not California

 

[blowerbike]

there is so much more power in the RS series miks.
36's will work on a stock motor or run 8's on a drag bike.
just a little hard to find used..

 

[maicojoe]

How about 40mm RS Mikuni's ?

How about 40mm RS Mikuni's ?

Do you think I could get a set of 40mm RS Mikuni's to work on my bike for street use? The reason I ask, is I have a set of almost new ones. Or anyone want to trade for a like set of 36 RS Mikuni's ? Just want something better for the current street engine that is in the bike now, while I build a better engine that will use FCR pumper carbs. The 40mm RS carbs I have now came off of a GS1230 drag bike. He made about 20 passes with them, and wanted more, so went to Lectron carbs. The reason I was looking at 40mm CV flat slides, are I reckon they are more street friendly than say 40mm race carbs? Long story, but the bike was supposed to come with 38mm RS carbs when I bought it, but showed up with stock 34mm CV Mikuni's. The 34's were jetted and tuned on a dyno, but I don't like them. They don't have the correct throttle response down low or in the mid range, like my old 1981 GS110E did, with the same 34's and stock air box. Once past say 5K-6K rpm, it comes on very strong though. Just don't feel like messing with the 34's on this type of engine, feel like I would be leaving a lot of HP on the table, plus want the bike to jump hard when I roll the throttle on, hence the interest in 40mm CV flat slides.

 

[blowerbike]

40 RS just to much to be enjoyable on a street bike of your size.
36 RS are hard to come by used.
40 RS are way more available used but...you may find a guy that thinks bigger is better.
post up an ad on CL for a trade...never know.
FYI
36/38/40 RS carbs new are all the same price.
34's are a little cheaper.

 

[maicojoe]

Ya, I paid $200 for these, they look new, in the factory box, with velocity stacks and a push/pull throttle . I just might throw them on for a quick try. Just wish I owned a chassis dyno....

 

[jimb12]

Do you think I could get a set of 40mm RS Mikuni's to work on my bike for street use? The reason I ask, is I have a set of almost new ones.

Yes I know from experience that you could. I had RS40s on an 1166 street bike and they worked fine. Just make sure that you use the push-pull throttle with flatslides. I agree that the RS36 would be a better match for your engine, but the 40 works if you understand smoothbores. With smoothbores, you control the throttle rather than a vacuum chamber doing it like on CVs. This means that if you whack the throttle open at 2500rpm with flatslides, you'll bog it. Do the same thing with CVs and it won't, because you're not actually at full throttle in the above scenario. The larger the venturi, the bigger the hole you're opening, and therefore the more sensitive the flatslide carbs are to misapplication as this scenario describes. Proper application of throttle on a smoothbore means that you open the throttle as the engine is ready for it.

Since you already own them, I'd suggest trying them and see what you think. Check the jets, the baseline for the RS40 is: 17.5 pilot jet, pilot fuel screw 1/4 to 1/2 turn out, needle in groove #3, and a 140 main jet. Mine worked very well right out of the box like this at low altitude, using pod filters. With velocity stacks I went a little bigger on the jets. I would not recommend choking these carbs down with the stock airbox. If you don't like them, you can always try something else.

 

[blowerbike]

will they work...yes
will you be happy....no