38mm Vs Flatslide Carbs

[Anonymous]

They are not smoothbores, but are the same size. They should give a lot of extra compared to the stock CV34 on GS1100. I can?t however see an acceleratorpump on them, but so does the SB33:s miss....That means that from idling RPM you can?t rev it up too quickly, since the gasoline is sucked directly from the throttle needle - main jet, sounded strange even to me but hopefully you know what I mean.
With pods and a 4-1 you can start with 127,5 main jets and go from there. On my bike I used that and it worked fine, ran a little rich in the midrange so I lowered my needles one step.

 

[Anonymous]

OK so here is yet another question 8O
I know a bit about CV and flatslades - i.e. I understand the differences and the pros and cons - and have riden bikes with both. But I do not know about smoothbores Can anyone fill in the gap in my knowledge :?: What are the pros and cons of smooth bopres compared to CV and flatslides :?: :?: :?:

 

[skip]

chrille_08 wrote:skip] :

Do you have a ported head on your beast?

Its mildly ported with boots matched to the carbs and the intake matched to the boots. mild porting inside the head and oversize valves it was a $ 600 port job at the time(not including parts) and I got a price break because the shop I went through got a dealer discount and passed it on to me

 

[Anonymous]

With flatsides and not beating it to death all the time, what kind of gas mileage should you get?

 

[skip]

Because of of the acceleration pumps if you twist the gas alot your milage will fall into the twenties but baby it a little or do some highway and you should be up in the forties

 

[GER144]

BikerShaun, here's the differences on the flatslides-smoothbores-CV's.
Basically the smoothbore name is applied to any carb that is not CV. You can have smoothbore flatslides, and CV flatslides. Smoothbore round slides, and smoothbore CVs'. Smoothbore flatslides are a hair more responsive than smoothbore round slides. All smoothbores won't have as nice drivability as CV's, but the RS's come damn close.
In a CV carb there is the throttle slide, and also a throttle valve. The throttle valve is connected to the throttle cable. Twist the cable, opens the valve (or butterfly) and the incoming vacuum rasies or lowers the slide. But that 'butterfly' -or valve, is always there so there is not a 'smooth bore' through the carb even when the slide is fully open. The valve is always in the way of airflow through the carb. Make sense?
There are basically 3 kinds of smoothbore flatslides. The Mikuni RS, the Keihin FCR, and the Lectron. My favorite is the RS's. I run RS40's on my 1428 dragbike, but I have also ran these same carbs on a completely stock '83 1100 Katana, and it carbureted and ran just fine. Different jetting of course. The FCR's are nice, but harder to find, and usually more money. The Lectrons are great too, but not good for the street. Dragbike only. I also have a set of Mikuni 33 smoothies with the rare accelerator pump kit on my '83, and they work pretty good, but not as nice as my RS's. If I were you, save your pennies and get a set of RS's instead of CV's. They work so nice, and their drivability is nearly as good as CV's when set up properly.

 

[Hoomgar]

GER144, can you give some info on where to find some RS's at a good price? And what size/type would I look for to put on my GS1000C. We bored it to about 1100 and port and polished the head. Was going with a set of 34mmcv's on it but would I be better of with the RS's?

Thanks for any info.

 

[Anonymous]

[/quote]can you give some info on where to find some RS's at a good price?

Take a look at these:

http://cgi.ebay.com/ebaymotors/ws/e...5597&item=2457181676&sspagename=STRK:MEBWA:IT

No idea what they will go for, but the typical winning bid is around $350-$400USD.

Mark

 

[rosco15]

I can't help but think flat slides are the cheapest way to make a ton of power. 36 mikuni flat slides, stock pistons, stock (no porting) head, V+H drag pipe, good ignition made 113 HP. I put in an 1166 low compression kit and I got 128 HP. Seems Isaac has a comparable motor, but he runs Keihin carbs, aftermarket cams, and has his head ported and makes 129HP (darn near the same). I would think with a set of Mikuni's, the porting, and cams, his motor would make a ton more power than I got.
HOOMGAR, Just a note. The 36's on the stock motor seemed a little big. I did some head work and might put on my 38 flat slides, but am worried they are too big.

 

[skip]

I can't help but think flat slides are the cheapest way to make a ton of power. 36 mikuni flat slides, stock pistons, stock (no porting) head, V+H drag pipe, good ignition made 113 HP. I put in an 1166 low compression kit and I got 128 HP. Seems Isaac has a comparable motor, but he runs Keihin carbs, aftermarket cams, and has his head ported and makes 129HP (darn near the same). I would think with a set of Mikuni's, the porting, and cams, his motor would make a ton more power than I got.
HOOMGAR, Just a note. The 36's on the stock motor seemed a little big. I did some head work and might put on my 38 flat slides, but am worried they are too big.

i dont think the 38's will be too big with the rest of ther work you have. I have the 38's with a 1229 kit and g-4 cams and the combo runs great, my buddie has 38's on a stock 1150 with headwork and g-4's and loves it.

 

[GER144]

Hey Hoomgar, the places I would try for some RS's would be either Ebay, or the dragbike.com classifieds. Sometimes you'll see them for sale in 'bargain finders' or bike trader magazines. I missed out on a set of magnesium RS38's a few years ago that were advertised in the local Bargain Finder. They would've been cool. The ones Mark posted above that are on Ebay would work. It doesn't say what size they are though? They say they are for '89-'92 GSXR, but that is ok. The GS's and oil-cooled GSXR's have the same carb spacing. (KZ too)
For your bike Hoomgar, I'd go with 36 or 38's. Usually the smaller RS carbs (34mm-36mm) are cheaper than the 38's or 40's. Keep that in mind. Smaller carbs make more torque, the bigger carbs will get you more top end. Don't be scared of the big carbs! I had RS40's on my completley stock '83 Kat 1100, and it carbureted just fine. I even ran that '83 on alcohol with these carbs once!