gsxr slingshots on gs1100 float height?, HELP!

[stiksave]

Here's what I've been able to dig up on these carbs. They are Mikuni BDST 36MM. They are from a 1994 Suzuki RF900. The stock jets are 130's. I think they are down draft, so the have to be tipped like the flatslides. Here's a description of the bike, http://www.mcnews.com.au/Testing/rf900.htm . I do have a pair of 2 x 2 K&M's that would help with room for the tipping if the carbs. The next question would be, will they be an improvement over my CV roundslides with dyno stage 3 installed? The jets in my carbs are 135's. Next question. Is there a good exploded veiw and spec chart for this carb some where?

Thanks,
Chris

[gsBert]

not to be a pain in the backend here, but make your own thread...

do you guys realise that this thread "help me with my float heights with gsxr slingshots on an 1150 engine" has been completely hijacked...

we're discussing a different carb on a different engine, on a different bike.
thansk for all the help, really, should i feel slightly upset?
i mean its interesting readingf and all, but everytime i see a reply to this post i get all excited becasue someone might have posted their actual float heights, only to find out what i already knew: the rf 900 carbs suck on the 1100 engine.

what you want are either slingshots or rs36, but if you plan on doing any street driving you want the slingshots, all you need is to get your hands on some (flatslide cv carbs) and pray (as i do) that someone posts the correct float height for our engines...

[stiksave]

Sorry Dude

[pano]

gsBert,

I dug this all up from searching this site a while back. There is some reference to the float heights in here. I have a set but have not had the time to fiddle with them yet.


........After having read many posts about the GSXR Slingshot carb mod for GSs, I obtained what I am pretty sure are some '92 Slingshot carbs for my '81 GS1100E. However, upon inspection, they appear to be downdraft carbs, with the bowls at about a 15 degree angle. Does anyone know if this will be problematic in terms of spilling fule into the cylinders, and does anyone have a solution? I would really appreciate some advice, before I wash out my cylinders and blow my engine. Thanks for any help.

Austin

I'm running the 90 GSXR 11's (36mm) on an 1150 with no problems now. I too was concerned about the angle. I had to lean the float height considerably to get it to run right. I bought my carbs used, and I think they may have been fiddled with previously.

The dyno jet kit that came with the carbs had these super blunt looking needles and huge mains. I fouled about 24 plugs, four at a time, until I leaned the floats.

In the meantime, I bought a Factory jet kit and the needles looked totally different, slim and pointy. I tryed these and fouled half the plugs mentioned above. My emulsion tubes, where the needle slides into, may have been fiddled with also so I stuck with the Dynojet kit. I'm using 32 pilots and 147.5 mains with the needle 4 notches down. I had it a 3 for a long while, but was experiencing detonation in the lower rev range. This change solved that..

I would reccomend a jet kit and K&N filters. If the idle adjustment screw is on the bottom it might need to be shortened, but if on the side with the long cable, no worries. The throttle cable needs to be shortened or a GSXR used. I modified my stock throttle housing to accept the GSXR cable, as it has a different end. Carter

Carter,

Do you have your carbs tilted somehow (like tied up to the frame) to level out the float bowls, or did you just leave them straight, with the float bowls at an angle? What height did you set the floats at, and are you sure that there's no raw fuel seepage into the cylinders? Have you ever checked the intake boots after riding to make sure that there's no fuel seepage? Are your plugs the right color? I want to use these carbs, but I'm nervous about cylinder washout. Any other information from you or anyone else would be extremely useful. Thanks to all.

Austin

Austin

I dont have them tilted, but I did fabricate a crude aluminum bracket to support the carbs to the frame. I mounted on the top of the inner carbs to the bar that supports the four carbs and connected to the two holes in the frame where the airbox used to mount.

The reason for the brackets is to support the weight without an airbox, but also maybe half a dozen times, I've started the bike and the negative back pressure or whatever its called, blew my carbs right off the boots. I also had three boots burst on startup.

Hopefully this is caused by the backpressure and not seepage.

My plugs tips almost look like they do when new, but inside the threads are darker. I actually think I'm running a little rich, but thats to cure the detonation on the 1229 with a little more compression than stock.

The floats are set at 17-18mm, almost as far as you can go. I had a shop do it as my hand dexterity is clumbsy.

When I've taken my carbs off, I noticed residual fuel on the ends of the boots, but I recall this with stock carbs too.

The power delivery is amazing, the pickup off the bottom, and the lightness of the twistgrip is addicting. Feels like a new engine.

One hot tip is to mount the cable to the carbs before installation, then route the cable through the frame. Try it the other way and you'll cussing and cursing. Carter

If you can get a copy of a book titled "Superbike Preperation" by Jewel Hendricks, it goes into detail on this subject and many others dealing with engine and suspension modifications. It was written in the mid 80's and it deals with these older bikes before fuel injection and shim-under bucket valve trains became the norm. My copy is full of greasy thumbprints, it is well worth the $20 or so bucks. Ride On, Ed.

I'm running GSXR carbs on my 83 Kat. It does have an 1150 motor in it but I dont' see a problem running them on the 1100 as I've tryed 36mm 1150 carbs on my 80 1100 with no problems except a rich idle circuit or improper float height.

I'm currently using 90 36mm GSXR 1100 carbs with stage 3 jet kit and dual K&N's. I think you'll run into problems trying to plumb them on a stock 1100 airbox setup.

I had to fiddle a bit with float height as I was told the GSXR carbs are sensitive to float height. I was told to start at 14mm float height but ended up fouling numerous plugs over and over until I set them at 17-18mm. Actually you may have better luck with a Factory jet kit and 14mm may work. I bought a Factory jet kit and tryed to install them in the carbs that had previously housed a Dyno Jet kit and I think the copper emulsion tube that surrounds the needle had been bored out before I bought them. That maybe why I was fouling plugs.

The throttle response was impressive and more immediate with lighter throttle action. The main jets were Dyno Jets equivalent to roughly a 160 Mikuni which seemed a bit big. I'm now running 145's.

Its a bit surgy around 2500-3000 rpms in 2nd and 3rd around town stuff and a delicate throttle hand is required at this low steady rpm. Otherwise its a vast improvement throughout the rpm range. Felt like a new motor was installed the first time I dialed them in right.

I did have to shorten the throttle cable, running a GSXR cable housed in the stock 1100-1150 throttle assembly. I also had the idle speed adjustment screw shortened as it was touching the cam chain tensioner.

I'm running a Pingel petcock with no vaccum line. You also must use a T- fitting to plumb the dual fuel line from the carbs. It's a go if you're into a little fiddling. I don't know anything about accelerator pumps. Carter Turk

[Flo]

have two GS bikes running with such carbs (GSXR and BAndit). Never cared about that float bowl height thing. Just set them up like in the GSXR-handbook, runs fine!

I run:
-org. 83 GS1100E-Motor
-36mm CVs from some 1100 Gixer, dont know exact year, might be 90
-K+N-duplex
-Laser 4in1 full with street legal pot

needle, air corrector jets and stuff all org. (dont know numbers, whatever was inside)
idle screw 3 turns out
142,5 main jets
O2-meter shows great reading, full throttle at > 6500 rpm could be richer. Is close to lambda1, great for economy, engine and environment, not perfect for power. But bike runs great, faster than I can drive of course, so no need to change. Better than with stock 34CVs from stoneage.

my other setup:
GS1150
-bored to 1200, 11/1 compression
-36 CV from 97 BAndit 1200
-Speedpro-4-1 with open Race-pot
-K+N-duplex
-HD150
-needles in highest postition + washer M3 under each (I know carbs are precision parts and washers arent... but it simply works great and was the only thing I has available)
-idle screws according to o2-meter (dont know how many turns, sorry)
here someone could go a bit richer too. But it runs GREAT (wheels 1st and 2nd). Correction for all out power should be done with air correctors as mid range is just perfect (acc. to O2 and my "seat of pants")

the BAndit carbs seemed to be set up much leaner in the mid range (Smog regulations?), so they need much more tweeking... easiest point to start are definetely the Gixer-parts.

the 1100 runs like that for two years now and I am really happy with it. It is in every way equal or better than the orig. setup or the 36mm 1150 carbs I tried. The modern carbs arent as worn out as the antique stuf, parts are cheaper and readily availabale and be honest: they are simlpy a more modern and tricked out design!
Manual Flatslides are fine for some people... I dont like them! I managed to slide out of a corner with a spinning rear wheel with the setup above, it really kicks enough!

I sold my GSXR1100W to my brother, up to 180km/h the fresh built GS1150 kicks his ass ;-)

Regards
Flo