GSXR carbs

[Flo]

To my big surprise it seems to run great in the mid range but only the o2sensor tells the real shocking truth... I really wonder about this because with my former GS1150 carbs I put the needles one or even two steps higher than original when changing to K+Ns... I cant tell you if the pre-owner had done some changings (carbs laid in shelf for maybe 3 years... came to me from ebay) but at least there was no dynojet installed. I just jetted them according to my experience and the first try was a really nice run! And then the weather became ugly...
the 142.5 jets are original Mikunis, as I heard a lot of bad reputation about the Dynojet-stuff and the orig parts are quite cheap... and until now I was able to get appropiate results with Mikuni parts...
A tip from me to all customizers out there: get an o2-sensor from junk yard and build yourself or buy from K+N or somewhere else an o2-meter. It REALLY pays and will cost you <20,- bucks if diy. An wideband o2 will bring you even more far but is not absolutely necessary and more costly...
Regards
Flo

[scotty]

Do you have an O2 sensor mounted in head pipe??

[Flo]

I welded in a thread in the connector pipe between header and muffler. Directly behind the 4-1 collector.

[Anonymous]

Project update:
Got everything up and running (finally), looks like I had a flaky plug wire/connection that happened to be temp sensetive, it really confused my carb tuning process.
whith that fixed, carbs synced and jetting : 32.5 pilots, 130 mains, and 0.5 mm shim under the needle, It idles like a champ.
Went for a round the block ride and WHHHEEEEEE...HHAAA....the difference is amazing, pulls well and smooth from idle up, throttle response is crisp and better than ever. In first and second gear, comes on even harder at 6500 rpm.
Getting just a hint of popping on decel, but very little. I think I may need to eventually go up on the mains, but I will not know till I can go for a longer ride and get a read on my plugs.
I am still using the pods from my old carbs( with an adapter) and the inside diameter may be providing enough restriction that the 130 mains are big enough. I think that the oval pods have a much bigger inside cross-section.

But it can be done, and so far it runs hard.

Ps. be careful around the plastic caps, particularly the vacuum nipples, it does not take much to snap one off, like by dropping a socket...


Later,
Derrick

[pano]

Thanks for the update.

I am looking forward to getting mine on but I got to finish up the few other things on my plate. As soon as I do I will post.

Thanks

[Anonymous]

well, after a longer ride today, still runs pretty well, after it really warms up the idle gets a little sporadic, and the plugs are lookin a little lean. I will richen the idel mixture a little and see how that goes. If tha does not fix I will go after the needles and maybe a main jet. I may have to buy a Jet kit after all, just to get the adjustable needles.
I want to re emphasize that the throttle return action is very light, I had a littel friction in my cable and it was enough to hang the revs during shifts.
I replaced the 1100E cable with the newer Katana one (took a little modification on the handle bar side) and that seems to fix the problem. The newer cable seems to have a heavier sheath, less likely to kink.

It's about the journey right?.......right?......

Derrick

[Flo]

Update

stock GS1100engine, 36 GSXR-carbs with 142,5 Mikuni main jets, other orig GSXR-setup, K+N dual filters, Laser 4-1 full exhaust street legal, a bit more ignition advance

I just had a longer ride this weekend, having time to watch the O2-meter. Setup works really nice! Maybe at top I could get one step bigger (145 or 147,5 as I am very clos to LAmbda 1, should be more to 0,9... 0,8) for more hp but it runs nearly perfect, very smooth and always a bit on the fat side according to measuring

[Anonymous]

well, after a longer ride today, still runs pretty well, after it really warms up the idle gets a little sporadic, and the plugs are lookin a little lean. I will richen the idel mixture a little and see how that goes. If tha does not fix I will go after the needles and maybe a main jet. I may have to buy a Jet kit after all, just to get the adjustable needles.
I want to re emphasize that the throttle return action is very light, I had a littel friction in my cable and it was enough to hang the revs during shifts.
I replaced the 1100E cable with the newer Katana one (took a little modification on the handle bar side) and that seems to fix the problem. The newer cable seems to have a heavier sheath, less likely to kink.

It's about the journey right?.......right?......

Derrick

You may want to think about increasing the return spring. A different cable is giving a false sense of security.

[pano]

I am finally starting to take a look at installing the GSXR carbs and want to make sure I set these up right. can you guys correct me if I am wrong.

It looks as though I have a dual fuel feed, one to the left pair and one to the right pair.

Above the dual feeds I have my vent hoses one for each pair

That seems clear but here is where it gets fuzzy, on top of the carbs I have rubber caps on carbs 3 and 4 and on carbs 1 and 2 the caps are missing. Am I missing the cap for carb 1 and carb 2 connects to the vacuum port on the petcock?

If using a Pingle without vacuum do I cap off all 4 of the carbs on top?

Thanks

[RacingJake]

Your right, if not using the vacuum petcock then just cap them off.

[pano]

Thanks Racingake

[isaac]

So what happened with this? I wanted to know how much of a boost those 2mm bigger carbs gave the 1100.

[pano]

I am still working on mine but I wil give you a comparison when done.

[Detman101]

8O
What in the.... Scotty on a GSXR!?!?!
I go away for 6 months and everything changes topsy turvy....

Dm of mD

I think RJ's and mine are supposed to be the slingshot carbs which I believe are the semi flatsides. Scotty I thought I read somewhere you had a set but hadn't put them on yet...but that was a while ago.

I picked them up because of what I read on this site. I want to see how they work.

yes i still have a set of 36mm semi flats from a 1996 750 Katana. They are spotless and still have the stock jetting in them. I got threm off ebay for just about $100 and sunk almost that amount into them for the parts i needed to modify them to a manual choke mounted on the left side of the carbs. i also modified an air box to go with them with a piece of very large pvc union cut and epoxied into it so i could run a huge K&N.
The idea is to have max air flow and not lose the dead air effect that the air box gives.
Now i wont use it because my gsxxxrrr 750 will get a set of real flatslides.

[Anonymous]

Hey Issac,
Now that I have finally got my 36mm carbs set up and running well(except for an intemittent oil seep, but that is another story), my 83 1100e seems to accelerate harder and pull a lot harder at the midrange and top end. Keeping in mind that the stock carbs that came with my bike were in pretty bad shape. Hopefully I will get a chance to ride with some of my fellow GSR bretheren some time this summer, and get a comparison with another 1100.

Derrick