rs flat slide carbs

[slideplayer]

Hi peeps, anyone fitted these to a gsx 1100 e 1980 ? What size is needed for a standard engine, 34, 36, 38 ? Any major problems mounting them, is it possible to retain some of the original air box and cut off the front for the filters. How difficult are they to tune to the bike, are they worth the money ? Not looking for extra performance, just a reliable bike that runs well, giving up trying to fix the original carbs. Any information most welcome, many thanks.

[Steve]

I have never done it, but I would guess that if you are not looking for extra performance, it would not be worth whatever it takes.

Unless the original carbs have been sitting on the bottom of a river for a while, it shouldn't be that hard to "fix" them. With a stock engine, they should work quite nicely.

What is wrong, that you are trying to fix?

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[Buffalo Bill]

If you're looking for new carbs for normal riding, use the 34mm. That said, you're on your own for tuning because those carbs are designed and intended for racing and custom tuning.

[GregT]

If you're looking for new carbs for normal riding, use the 34mm. That said, you're on your own for tuning because those carbs are designed and intended for racing and custom tuning.

They're easy to tune. If you get them pre-jetted from Sudco, they will be very close to dead right. It's always more pleasant working on new unworn instruments.

[Buffalo Bill]

They're easy to tune. If you get them pre-jetted from Sudco, they will be very close to dead right. It's always more pleasant working on new unworn instruments.

I agree with new is better, but part of tuning is air filter style. So Slideplayer will have to test for the best tuning for his air filters and exhaust system. Maybe a chart will come with the carbs.

If I had the money, I'd buy a new RS set for my track bike.

[slideplayer]

Hi peeps, the problem with the original carbs is the pilot fuel adjustment screws don't do much, from almost screwed right in to 5 turns out, the motor runs rather fluffy not running crisply and evenly. The pilot jet slots are not good, so trying to get them out could be bad news, but the carbs have been cleaned 5 or 6 times ultrasonically and manually. The other problem is the bike stalls around 4 to 5 thousand revs, closing the throttle brings the engine back to life, and runs normally at around 4 thousand. Plugs are black coloured. Main jets are standard size, new diaphragms, any ideas most welcome, many thanks.

[Buffalo Bill]

Can't have an opinion without examining carbs and all components.
I'd suggest sending them to a CV carb builder, if you can find one in Europe.
We have a few on site here, but US based.

Last fall I spent weeks tuning and testing the carbs in my track bike. Continued again this spring into summer.
Got the idle circuit set first with a Gunson Colortune, plus carbs synchronized.
Wanted to be sure I was getting full power potential from 9000 to 12,000 RPM so:
Tried a step bigger jets but that was too much, went back to standard size.
Tried a higher flow air filter, degraded performance so went back to standard.
Plugs continued to blacken and foul.
Final trick that worked was lowering the needles one slot. That's an adjustment to lean out the midrange RPMs.
Bike's had such good consistent performance since, I haven't taken the tank off to examined the plugs.
Hope this story helps.
Carbs have 3 tuning zones: Idle circuit up to 3000 RPM, Needle height through Midrange, Main jet size for Wide open top end.
CV carbs run best overall with OEM airbox, pod filters only good for wide open top end.

[Tom R]

There are several ports for the pilot system.... only one is on the engine side of the throttle plate. If this one’s clogged, I’ve seen people compensate by opening the throttle plate more to allow the others to come into play. It’sa bandaid fix and you will never get it to run right. Not sure if this is your problem, but something to consider. Did you disassemble carbs 100% to clean them? Soak overnight? Adjustable clips on the needles? Which notch? All air jets clear? Did you remove the needle jets and make sure the emulsion holes are clear? Is the enrichment (choke) dystem closing all the way? Sealing up?
Not sure how thoroughly you cleaned them, but unless they were highly corroded, they’re likely repairable.

[slideplayer]

Hi peeps, thanks for all your replies, yes carbs completely stripped many times before cleaning, rebuilt as per standard specs, float height correct, needle middle notch, emulsion tubes perfectly clean, new float valves and seats, new diaphragms, head to carb rubbers, and still won't run properly. Is suicide really painless ????????? Perhaps those tiny holes in the throat are still blocked, but how to clear them for good slow running ? Will drop the needle a notch to try and overcome the 4 / 5 grand present rev limit, but those little holes have been ultrasonically cleaned professionally several times, is it possible to clear them with a guitar string, how about battery acid, or a very small rodent ? Nice bike, shame about the carbs.

[Buffalo Bill]

I use guitar strings to poke out the jets, works good. Check with high power magnifier, crud builds up in there…

[Tom R]

You do have the rubber plugs over the pilot jets... right? Not trying to be insulting, but you wouldn’t be the first.

[Steve]

While there is a lot to be said in favor of ultrasonic cleaning, I don't know how well it works to get into the small passges that comprise the pilot fuel system.

Do you have proper chemicals available? We have carb cleaner dip that we use to soak the carb bodies in overnight. The directions on the can say to dip the parts for 15-30 minutes, but they were probably written many years ago, when the chemicals inside the can could actually do the task in that amount of time. Over the years, the Environmentalists and other Safety Weenies have weakened the chemical so we have to dip the carbs for 15-30 HOURS to get the job done. Even after sitting in the dip all that time, it still takes a good shot of carb cleaner spray and a blast of compressed air to verify that all the passages are clear.

If you do have chemicals available, feel free to try them, but whatever you do, DO NOT immerse any of the rubber parts, like diaphragms, "choke" plungers, etc.

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